We are searching data for your request:
Upon completion, a link will appear to access the found materials.
When a cure has been found for a virus, can it be called such anymore?
Virus implies it's something you've contracted that you just have to live with until (hopefully) your body can overwhelm and destroy it.
But say someone found a cure for the Common Cold tomorrow, would we still call it the cold virus or would it just be known as the "cold infection" or something to that effect?
Is "Virus" just a nomenclature we've adopted for a bug that has no cure, or is it used to describe a certain type of organism?
Lets start with the definition of a virus (from the Wikipedia page on viruses):
A virus is a small infectious agent that replicates only inside the living cells of other organisms. Viruses can infect all types of life forms, from animals and plants to bacteria and archaea.
So basically speaking you have a piece of genetic information (DNA or RNA) which encodes proteins which are important for the function of the virus and a hull (not always, but mostly). These invade a cell type, take over the cell (litarally, after an infection the cell will mostly only make viral proteins and DNA/RNA). Finally new viruses are built inside the cell and released to infect more cells. In principle this works like in the figure below (from here):
There are two possibilities for cures: The first one are vaccinations. Here you either use dead or attenuated viruses (or parts of viruses) to train the immune system. When this has happened, the immune system "knows" this specific agent and can rise a fast and highly specific immune answer against it, before the virus can replicate in high numbers and infect a lot of cells. This happened for example for the small pox virus which could be eradicated from the human population.
The other would be drugs which either target a virus (or some of it functions) specifically or prevent them from spreading. The immune system usually does the final cleanup here.
Both methods only work for people which either take the drug or are vaccinated, so they have no influence on the virus in people which are not protected. For further information have a look on the Wikipedia page on Viruses.
We're beginning to understand the biology of the covid-19 virus
THE covid-19 virus is humanity’s newest foe, with the potential to prematurely end millions of lives. To control this new coronavirus, we need to understand it. Labs around the world are now working around the clock in a bid to know their enemy.
Three crucial questions are occupying virologists. What makes the new virus so good at infecting people? How does it reproduce so quickly once it is inside us? And why doesn’t the virus cause symptoms straight away, allowing it to &hellip
Article amended on 23 March 2020
We clarified what structures researchers are determining.
Article amended on 24 March 2020
We clarified that disrupting the virus's ability to copy itself can help people infected with covid-19.
Subscribe for unlimited digital access
Subscribe now for unlimited access
App + Web
- Unlimited web access
- New Scientist app
- Videos of over 200 science talks plus weekly crosswords available exclusively to subscribers
- Exclusive access to subscriber-only events including our 1st of July Climate Change event
- A year of unparalleled environmental coverage, exclusively with New Scientist and UNEP
Print + App + Web
- Unlimited web access
- Weekly print edition
- New Scientist app
- Videos of over 200 science talks plus weekly crosswords available exclusively to subscribers
- Exclusive access to subscriber-only events including our 1st of July Climate Change event
- A year of unparalleled environmental coverage, exclusively with New Scientist and UNEP
Existing subscribers, please log in with your email address to link your account access.
A virus is a pathogenic, parasitic organism that isn’t classified as being alive, since a cell is an essential to our definition of life. A virus has no cell membrane, no metabolism, no respiration and cannot replicate outside of a living cell. A virus is a creepy half-live, single strand or double strand of DNA or RNA or both, looking for a cell to invade. Once inside, it reprograms the cell with its DNA or RNA and multiplies on mass, bursting through the cell with a thousand or more new virus strands seeking new cells to invade. RNA viruses mutate more easily than DNA viruses. (SARS, bird flu, West Nile virus, swine flu, hepatitis, measles, polio, yellow fever, and Ebola are among the many RNA viruses).
If two viruses invade the same cell (a bird virus and a human virus, for instance) their DNA can combine to form a new virus, a potentially virulent one. The same is true if two animal viruses combine and jump species to humans.
Viruses have two life cycles: the lytic cycle and the lysogenic cycle.
In the lytic cycle, the virus focuses on reproduction. It invades a cell, inserts its DNA and creates thousands of copies of itself, bursts through the cell membrane, killing the cell, and each new viral strand invades new cells replicating the process.
In the lysogenic cycle, viruses remain dormant within its host cells. The virus may remain dormant for years. Herpes and chickenpox are good examples. (Chicken pox can cause shingles in later life when the dormant virus reactivates.)
Vaccines Help The Immune System Kill Viruses
Viruses are very tricky things to handle. They create disease by using the host&rsquos cellular machinery to reproduce. To eliminate them from the body, one has to kill the virus without harming the healthy cells around it.
Remember those vaccinations I mentioned earlier? They are a key line of defense to help our bodies ward off viral invasions. These vaccinations act as reminders for our bodies, in case we become exposed to the same virus again. Our immune systems destroy the virus by secreting chemicals that kill virus-infected cells, thereby preventing the virus from multiplying, and/or secreting antibodies that put a death signal on the virus so that immune cells, such as the macrophages, can come and kill it.
For example, one injection for measles will provide a lifetime of resistance if our body ever encounters the measles virus again!
However, if these vaccinations are so effective, why don&rsquot they work for all viruses?
Viruses and the ways they infect a cell are very diverse. Some viruses are easier to kill than others, either because they lack a strong defense against our immune system or because we managed to develop a strong enough vaccine to stimulate the immune system. However, many viruses are tricky because they are able to evade our vaccines.
Creating New Vaccines When A Virus Mutates
One way that viruses become difficult to kill is through mutation. The host of different viruses that cause the flu, for example, mutate rapidly. Their genetic material and their protein coats will soon be different enough to hoodwink the immune system.
Take a look at the protein surface in the picture above. These protein surfaces continuously change when a virus mutates, and when this happens, our bodies can&rsquot remember if they&rsquove fought with this particular virus or not. Therefore, the vaccine that worked so well last year won&rsquot work the next time around.
Every year, scientists must create a new vaccine for newly identified strains of flu viruses.
The human immunodeficiency virus (HIV), which causes the disease AIDS, has posed an as yet insurmountable challenge for vaccine designers. The virus infects immune cells, our defenders against disease. With our immune system out of commission from the virus, it becomes difficult to find a vaccine to fight itself. And then, once the HIV virus starts to replicate, it&rsquos difficult to distinguish a healthy cell from an infected one. How do you expect to kill something like that?
HIV is one extreme case of the viral world, but it reveals just how complicated it is to deal with viruses. Scientists have been searching for an answer to this same questions for many years. There have been numerous experiments and theories concerning the best way to handle viral infections, but not a single solution that works every time.
Virus-like nano particles are being used to treat virus diseases like RSV. Credit: nanotechmag.com
This issue even involves nanotechnology, which seems to be all the rage this century! Vaccine developers are now using nanoparticles to specifically target viruses. In 2020, a paper published in the journal Science looked at the immune response to a nanoparticle vaccine against respiratory syncytial virus.
12 Deadly Diseases Cured in the 20th Century
According to the U.S. Census Bureau, the average life expectancy at the beginning of the 20th century was 47.3 years. A century later, that number had increased to 77.85 years, due largely to the development of vaccinations and other treatments for deadly diseases. Of course, vaccines and treatments only work if they're given, which is why many of these diseases still persist in poorer, developing countries. Despite the success of vaccines, only one of these diseases -- smallpox -- has been erased from the globe.
Here are 12 diseases that could be completely eradicated from the world if vaccines were made available to all.
Before 1995, a case of the chicken pox was a rite of passage for kids. The disease, caused by the varicella-zoster virus, creates an itchy rash of small red bumps on the skin. The virus spreads when someone who has the disease coughs or sneezes, and a nonimmune person inhales the viral particles. The virus can also be passed through contact with the fluid of chicken pox blisters. Most cases are minor but in more serious instances, chicken pox can trigger bacterial infections, viral pneumonia and encephalitis (inflammation of the brain).
According to the Centers for Disease Control and Prevention (CDC), before the chicken pox vaccine was approved for use in the United States in 1995, there were 11,000 hospitalizations and 100 deaths from the disease every year. Many countries don't require the vaccination because chicken pox doesn't cause that many deaths. They'd rather focus on vaccinating against the really serious diseases, so the disease is still common.
While chicken pox is still a relatively common occurrence, diseases like malaria and diphtheria seem to have been wiped out ages ago. Find out more about how these diseases were cured on the following pages.
Diphtheria is caused by the bacteria Corynebacterium diphtheriae and mainly affects the nose and throat. The bacteria spreads through airborne droplets and shared personal items. C. diphtheriae creates a toxin in the body that produces a thick, gray or black coating in the nose, throat or airway, which can also affect the heart and nervous system. Even with proper antibiotic treatment, diphtheria kills about 10 percent of the people who contract it. The first diphtheria vaccine was unveiled in 1913, and although vaccination has made a major dent in mortality rates, the disease still exists in developing countries and other areas where people are not regularly vaccinated. The World Health Organization (WHO) estimates that worldwide there are about 5,000 deaths from diphtheria annually, but the disease is quite rare in the United States, with fewer than five cases reported each year.
Invasive H. flu, or Hib disease, is an infection caused by the Haemophilus influenzae type b (Hib) bacteria, which spreads when an infected person coughs, sneezes or speaks. Invasive H. flu is a bit of a misnomer because it isn't related to any form of the influenza virus. However, it can lead to bacterial meningitis (a potentially fatal brain infection), pneumonia, epiglottitis (severe swelling above the voice box that makes breathing difficult) and infections of the blood, joints, bones and pericardium (the covering of the heart). Children younger than 5 years old are particularly susceptible to the Hib bacteria because they haven't had the chance to develop immunity to it. The first Hib vaccine was licensed in 1985, but despite its success in the developed world, the disease is still prevalent in the developing world. WHO estimates that each year Hib disease causes 2 to 3 million cases of serious illness worldwide, mostly pneumonia and meningitis, and 450,000 deaths of young children. If you're not familiar with diseases like the invasive H. flu, see the next page to read about the cures for more household name diseases such as the measles.
This disease is a parasitic infection of the liver and red blood cells. In its mildest forms it can produce flulike symptoms and nausea, and in its severest forms it can cause seizures, coma, fluid buildup in the lungs, kidney failure and death. The disease is transmitted by female mosquitoes of the genus Anopheles. When the mosquito bites, the parasites enter a person's body, invading red blood cells and causing the cells to rupture. As the cells burst, they release chemicals that cause malaria's symptoms.
About 350 million to 500 million cases of malaria occur worldwide every year. About 1 million are fatal, with children in sub-Saharan Africa accounting for most of the deaths. Other high-risk areas include Central and South America, India and the Middle East. Malaria is treated with a variety of drugs, some of which kill the parasites once they're in the blood and others that prevent infection in the first place. Of course, if you can avoid the parasite-carrying mosquitoes, you can avoid malaria, so the disease is often controlled using mosquito repellent and bed netting, especially in poor countries that can't afford medications.
Measles is a highly contagious viral illness of the respiratory system that spreads through airborne droplets when an infected person coughs or sneezes. Although the first symptoms of measles mimic a simple cold, with a cough, runny nose and red, watery eyes, this disease is more serious. As measles progresses, the infected person develops a fever and a red or brownish-red skin rash. Complications can include diarrhea, pneumonia, brain infection and even death, although these are seen more commonly in malnourished or immunodeficient people. Measles has historically been a devastating disease, but WHO reported in 2006 that measles mortality rates dropped from 871,000 to 454,000 between 1999 and 2004, thanks to a global immunization drive.
Until 1963, when the first measles vaccine was used in the United States, almost everyone got the measles by age 20. There has been a 99 percent reduction in measles since then, but outbreaks have occurred when the disease is brought over from other countries or when children don't get the vaccine or all the required doses. Most children today receive the measles vaccine as part of the MMR vaccination, which protects against measles, mumps and rubella (German measles). Read on to learn about a couple more obscure but often deadly illnesses: pneumococcal disease and whooping cough -- both of which have been cured in the 20th century thanks to science.
Whoop, there it is -- and if you suspect someone has it, move away. Pertussis, or whooping cough, is a highly contagious respiratory infection caused by the Bordetella pertussis bacteria. The descriptive nickname comes from the "whooping" sounds that infected children make after one of the disease's coughing spells. The coughing fits spread the bacteria and can last a minute or longer, causing a child to turn purple or red and sometimes vomit. Severe episodes can cause a lack of oxygen to the brain. Adults who contract pertussis usually have a hacking cough rather than a whooping one.
Although the disease can strike anyone, it's most prevalent in infants under age one because they haven't received the entire course of pertussis vaccinations. The pertussis vaccine was first used in 1933, but adolescents and adults become susceptible when the immunity from childhood vaccinations wanes and they don't get booster shots. According to the CDC, pertussis causes 10 to 20 deaths each year in the United States, and there were 25,000 cases reported in 2004. Worldwide, the disease causes far more damage -- about 50 million people around the world are infected annually, and WHO estimates around 294,000 deaths each year. However, 78 percent of the world's infants received three doses of the vaccine in 2004.
Pneumococcal disease is the collective name for the infections caused by Streptococcus pneumoniae bacteria, also known as pneumococcus. This bacteria finds a home all over the body. The most common types of infections caused by S. pneumoniae are middle ear infections, pneumonia, bacteremia (blood stream infections), sinus infections and bacterial meningitis. There are more than 90 types of pneumococcus, with the 10 most common types responsible for 62 percent of the world's invasive diseases.
Those infected carry the bacteria in their throats and expel it when they cough or sneeze. Like any other germ, S. pneumoniae can infect anyone, but certain population groups are more at risk, such as the elderly, people with cancer or AIDS and people with a chronic illness such as diabetes. The CDC blames pneumococcal disease for the deaths of 200 children under the age of 5 each year in the United States. WHO estimates that annually pneumococcal disease is responsible for 1 million fatal cases of respiratory illness alone most of these cases occur in developing countries.
There are two types of vaccines available to prevent pneumococcal disease, which the CDC recommends that children receive. In June 2019, the Advisory Committee on Immunization Practices — the experts who advise U.S. vaccine policy — stopped saying that all adults 65 or older should get the vaccine, too, instead suggesting that senior patients should discuss it individually with their doctor.
Since pneumococcal diseases are bacterial, doctors may treat them with antibiotics, but as with other bacteria out there, resistance can get in the way of successful treatment.
Shots preventing diseases like polio and tetanus are now commonplace. Continue reading to find out how these diseases were finally cured.
Of the deadly infectious diseases for which science has developed vaccines and treatments, people are most familiar with the victory over polio. The disease is caused by a virus that enters the body through the mouth, usually from hands contaminated with the stool of an infected person. In about 95 percent of cases, polio produces no symptoms at all (asymptomatic polio), but in the remaining cases of polio, the disease can take three forms.
Abortive polio creates flulike symptoms, such as upper respiratory infection, fever, sore throat and general malaise. Nonparalytic polio is more severe and produces symptoms similar to mild meningitis, including sensitivity to light and neck stiffness. Finally, paralytic polio produces the symptoms with which most people associate the disease, even though paralytic polio accounts for less than 1 percent of all cases. Paralytic polio causes loss of control and paralysis of limbs, reflexes and the muscles that control breathing.
Today, polio is under control in the developed world, and world health authorities are close to controlling the disease in developing countries, as well. Dr. Jonas Salk's inactivated polio vaccine (IPV) first appeared in 1955, and Dr. Albert Sabin's oral polio vaccine (OPV) first appeared in 1961. Children in the United States receive IPV, but most children in developing areas of the world receive OPV, which is cheaper and doesn't have to be administered by a health care professional however, in rare instances, OPV can cause polio.
Reproductive cells (spores) of Clostridium tetani are found in the soil and enter the body through a skin wound. Once the spores develop into mature bacteria, the bacteria produce tetanospasmin, a neurotoxin (a protein that poisons the body's nervous system) that causes muscle spasms. In fact, tetanus gets its nickname -- lockjaw -- because the toxin often attacks the muscles that control the jaw. Lockjaw is accompanied by difficulty swallowing and painful stiffness in the neck, shoulders and back. The spasms can then spread to the muscles of the abdomen, upper arms and thighs.
According to the CDC, tetanus is fatal in about 11 percent of cases, but fortunately, it can't be spread from person to person -- you need direct contact with C. tetani to contract the disease. Today, tetanus immunization is standard in the United States, but if you're injured in a way that increases tetanus risk (i.e. stepping on a rusty nail, cutting your hand with a knife or getting bitten by a dog), a booster shot may be necessary if it's been several years since your last tetanus shot.
According to the CDC, since the 1970s, only about 50 to 100 cases of tetanus are reported in the United States each year, mostly among people who have never been vaccinated or who did not get a booster shot. And WHO says that globally there were about 15,500 cases of tetanus in 2005. Read on to find out how the WHO and the CDC have nearly eradicated once-fatal diseases such as yellow fever and smallpox.
Typhoid is usually spread when food or water has been infected with Salmonella typhi, most often through contact with the feces of an infected person. Once the typhoid bacteria enter the bloodstream, the body mounts a defense that causes a high fever, headache, stomach pains, weakness and decreased appetite.
Occasionally, people who have typhoid get a rash of flat, red spots. Because sewage treatment in the United States is quite good, the disease is very rare, and the CDC reports only about 400 cases of it annually. However, people who live in developing countries where there is little water and sewage treatment, or where hand washing isn't a common practice, are at high risk. Prime typhoid fever areas are in Africa, Asia, the Caribbean, India and Central and South America.
WHO estimates 17 million cases occur globally with 600,000 deaths each year. Despite these daunting statistics, typhoid fever vaccination is available for people who travel to high-risk areas, and the disease can be effectively treated with antibiotics. Without treatment, the fever can continue for weeks or months, and the infection can lead to death.
Yellow fever is spread by mosquitoes infected with the yellow fever virus. Jaundice, or yellowing of the skin and eyes, is the hallmark of the infection and gives it its name. Most cases of yellow fever are mild and require only three or four days to recover, but severe cases can cause bleeding, heart problems, liver or kidney failure, brain dysfunction or death.
People with the disease can ease their symptoms, but there is no specific treatment, so prevention via the yellow fever vaccine is key. The vaccine provides immunity from the disease for 10 years or more and is generally safe for everyone older than nine months.
Yellow fever occurs only in Africa, South America and some areas of the Caribbean, so only travelers who are destined for these regions need to be concerned about it. WHO estimates that there are 200,000 cases of yellow fever every year, and 30,000 of them are fatal. The elderly are at highest risk of developing the most severe symptoms. Although vaccination and mosquito-eradication efforts have made a great difference, WHO says yellow fever cases are on the rise again.
Unlike other diseases on this list, which can still appear in outbreaks when vaccination vigilance weakens, smallpox has been wiped off the face of the earth, except for samples of the virus held in labs in the United States and Russia for research purposes.
Symptoms of smallpox included a high fever, head and body aches, malaise, vomiting. The most marked characteristic of the diseases is a rash of small red bumps, which progress into sores that break open and spread the virus (the virus could also be spread via contact with shared items, clothing and bedding). Smallpox was an entirely human disease -- it didn't infect any other animal or insect on the planet. Thus, once vaccination eliminated the chances of the virus spreading among the human population, the disease disappeared in fact, the United States hasn't vaccinated for smallpox since 1972.
Although smallpox was one of the most devastating illnesses in human history, killing more than 300 million people worldwide during the 20th century alone, scientists declared the world free of smallpox in 1979. The naturally occurring disease has been eradicated, but fears remain about the smallpox samples being used as bioweapons.
Helen Davies, Marjorie Dorfman, Mary Fons, Deborah Hawkins, Martin Hintz, Linnea Lundgren, David Priess, Julia Clark Robinson, Paul Seaburn, Heidi Stevens, and Steve Theunissen
Viruses are tiny infectious agents that invade host cells and cause disease. Although they are harmful, viruses also have interesting technological potential.
Viruses are microscopic biological agents that invade living hosts and infect their bodies by reproducing within their cell tissue.
Photograph by Maryna Olyak
Viruses are tiny infectious agents that rely on living cells to multiply. They may use an animal, plant, or bacteria host to survive and reproduce. As such, there is some debate as to whether or not viruses should be considered living organisms. A virus that is outside of a host cell is known as a virion.
Not only are viruses microscopic, they are smaller than many other microbes, such as bacteria. Most viruses are only 20&ndash400 nanometers in diameter, whereas human egg cells, for example, are about 120 micrometers in diameter, and the E. coli bacteria has a diameter of around 1 micrometer. Viruses are so small that they are best viewed using an electron microscope, which is how they were first visualized in the 1940s.
Viruses generally come in two forms: rods or spheres. However, bacteriophages (viruses that infect bacteria) have a unique shape, with a geometric head and filamentous tail fibers. No matter the shape, all viruses consist of genetic material (DNA or RNA) and have an outer protein shell, known as a capsid.
There are two processes used by viruses to replicate: the lytic cycle and lysogenic cycle. Some viruses reproduce using both methods, while others only use the lytic cycle. In the lytic cycle, the virus attaches to the host cell and injects its DNA. Using the host&rsquos cellular metabolism, the viral DNA begins to replicate and form proteins. Then fully formed viruses assemble. These viruses break, or lyse, the cell and spread to other cells to continue the cycle.
Like the lytic cycle, in the lysogenic cycle the virus attaches to the host cell and injects its DNA. From there, the viral DNA gets incorporated into the host&rsquos DNA and the host&rsquos cells. Each time the host&rsquos cells go through replication, the virus&rsquos DNA gets replicated as well, spreading its genetic information throughout the host without having to lyse the infected cells.
In humans, viruses can cause many diseases. For example, the flu is caused by the influenza virus. Typically, viruses cause an immune response in the host, and this kills the virus. However, some viruses are not successfully treated by the immune system, such as human immunodeficiency virus, or HIV. This leads to a more chronic infection that is difficult or impossible to cure often only the symptoms can be treated.
Unlike bacterial infections, antibiotics are ineffective at treating viral infections. Viral infections are best prevented by vaccines, though antiviral drugs can treat some viral infections. Most antiviral drugs work by interfering with viral replication. Some of these drugs stop DNA synthesis, preventing the virus from replicating
Although viruses can have devastating health consequences, they also have important technological applications. Viruses are particularly vital to gene therapy. Because some viruses incorporate their DNA into host DNA, they can be genetically modified to carry genes that would benefit the host. Some viruses can even be engineered to reproduce in cancer cells and trigger the immune system to kill those harmful cells. Although this is still an emerging field of research, it gives viruses the potential to one day do more good than harm.
Viruses are microscopic biological agents that invade living hosts and infect their bodies by reproducing within their cell tissue.
Eukaryotic viruses can cause one of four different outcomes for their host cell. The most common outcome is host cell lysis, resulting from a virulent infection (essentially the lytic cycle of replication seen in phage). Some viruses can cause a latent infection, co-existing peacefully with their host cells for years (much like a temperate phage during lysogeny). Some enveloped eukaryotic viruses can also be released one at a time from an infected host cell, in a type of budding process, causing a persistent infection. Lastly, certain eukaryotic viruses can cause the host cell to transform into a malignant or cancerous cell, a mechanism known as transformation.
Where Do Viruses Come From?
The origin of viruses is a hotly debated topic. It’s unclear how they first evolved. However, there are many ideas floating around out there. There are three classical hypotheses but many new ideas and discoveries challenging them.
The first one is the virus first hypothesis, and states that since viruses are so much simpler than a cell, they must have evolved first, and that ancestors of modern viruses could have provided raw material for the development of cellular life. The key data that supports this is apparent when you look at virus genes, compare them and their genetic sequence with cellular life data available in genetic databases. This will reveal a mismatch that suggests viruses aren’t a simpler version of cellular life, but are different fundamentally and might have predated cellular life altogether. This model also suggests there was an ancient virosphere from which all viruses evolved. However, some scientists dismiss this hypothesis because of one key feature. According to the classical definition of viruses, they need a host’s cell to replicate. So, how could viruses have survived before the existence of cellular life?
The second model is called the regressive hypothesis, sometimes also called the degeneracy hypothesis or reduction hypothesis. This one suggests that viruses were once small cells that parasitized larger cells, and that over time the genes not required by their parasitism were lost. The discovery of giant viruses that had similar genetic material to parasitic bacteria supported this idea. But what it can’t explain is why the tiniest of cellular parasites don’t resemble viruses at all.
The third model is escape hypothesis, or vagrancy hypothesis, and states that viruses evolved from bits of RNA or DNA that escaped from genes of larger organisms. For example, bacteriophages (viruses that infect bacteria) came from bits of bacterial genetic materials, or eukaryotic viruses are from bits of genetic material from eukaryotes like us. However, in this model, it would be expected that viral proteins would then share more qualities with their hosts, but this is largely not the case. This model also doesn’t explain the unique structure viruses have that is not seen in cells.
Some recent discoveries of giant viruses have even further complicated the question about the origin of viruses. These discoveries also challenge many of the classical definitions of what makes a virus, such as the size requirement, gene behavior, and how they replicate.
Giant viruses were first described in 2003. The first specimen was Acanthamoeba polyphaga mimivirus (APMV), isolated from an amoeba in cooling tower in England. The name “mimivirus” stands for MImicking MIcrobe virus because of the way amoebae mistake it for their typical meal of bacteria. Mimiviruses are different from viruses in that they have way more genes than other viruses, including genes with the ability to replicate and repair DNA.
The pandoravirus, discovered in 2013, is even larger than the mimivirus and has approximately 2500 genes, with 93 percent of their genes not known from any other microbe.
|Illustration: Nicole Elmer|
The pithovirus was discovered in 2013 from a Siberian dirt sample that had been frozen for 30,000 years. It’s larger than the pandoravirus, as well as some bacteria, and behaves differently than viruses when it comes to reproduction. According to the classical definition of viruses, they must have a host’s cell to reproduce and cannot do it on their own. However, the pithovirus possesses some replication machinery of its own. While it contains fewer genes than the pandoravirus, two-thirds of its proteins are unlike those of other viruses.
Tupanvirus was discovered in Brazil. It holds an almost nearly complete set of genes necessary for protein production.
The discoveries of these giant viruses and others not listed here have made some researchers suggest they lie somewhere between bacterium and viruses, and might even deserve their own branch on the Tree of Life. This would create a yet undescribed fourth domain of life aside from Bacteria, Archaea, and Eukaryotes. And in case you’re worried if these big viruses can infect us human being, rest easy. You only need to worry if you happen to be an amoeba.
In our next posting about viruses, we'll look at how they might be the most successful of earth's inhabitants.
Are there different variants of this coronavirus?
Yes, there are different variants of this coronavirus. Like other viruses, the coronavirus that causes COVID-19 can change (mutate). In December 2020, B.1.1.7, a new variant, was identified in the United Kingdom, and since then, variants have appeared in other locations around the world, including B.1.351, first isolated in South Africa, and others. Mutations may enable the coronavirus to spread faster from person to person, and may cause more severe disease. More infections can result in more people getting very sick and also create more opportunity for the virus to develop further mutations. Read more about coronavirus variants.
Coronavirus: What do I do if I Feel Sick?
Long Before COVID-19, Dr. Anthony Fauci 'Changed Medicine In America Forever'
President Trump's daily briefings on the COVID-19 pandemic have introduced millions of Americans to Dr. Anthony Fauci, the director of the National Institute of Allergy and Infectious Diseases. Evan Vucci/AP Photo hide caption
President Trump's daily briefings on the COVID-19 pandemic have introduced millions of Americans to Dr. Anthony Fauci, the director of the National Institute of Allergy and Infectious Diseases.
President Trump's daily briefings on the COVID-19 pandemic have introduced millions of Americans to Dr. Anthony Fauci, the director of the National Institute of Allergy and Infectious Diseases. At times, the specialist in infectious diseases has differed with the president during the briefings, correcting him on the seriousness of the virus or on the timeline for developing a vaccine. That's fueled speculation that Fauci's tenure might be cut short.
But New Yorker writer Michael Specter doesn't think Fauci needs to worry about job security. "Trump can't fire him," Specter says. "He can kick him off the coronavirus task force . but he can't fire him from his job."
Coronavirus Live Updates
White House Says Trump 'Is Not Firing Dr. Fauci'
Specter has known Fauci for decades — covering his work and the way he's handled the role of presidential adviser through six different U.S. presidents and the AIDS epidemic. Specter chronicles those ups and downs in the New Yorker article, "How Anthony Fauci Became America's Doctor."
"He's always taken an open-minded approach to the problems that he's faced," Specter says. "He's never been one, even in the early days, to say, 'This is how we do it and we're never going to do it a different way.' "
Specter notes that in the 1980s, during the height of the AIDS epidemic, Fauci worked with activists to amend the way the government handles clinical drug trials. The policy shift increased the number of patients who had access to experimental HIV/AIDS treatments — and saved countless lives.
The Coronavirus Crisis
Trump And Fauci Seek To Present United Front At Coronavirus Briefing
"This new system [for AIDS treatment] basically forced people to realize that you can't run drug trials and decide what to do with patients without ever consulting patients," Specter says. "I think it changed medicine in America forever."
Fauci continues to be forward-thinking in his approach to COVID-19, Specter says: "He wants to make a difference. He sees his job as marshaling evidence and presenting it to the people who need to know what he's talking about."
On how Fauci's studies in humanities may have influenced the kind of physician he became
Fauci spent a lot of his life studying Latin and Greek and romance languages and philosophy. He was very deeply concerned with the humanities. He wasn't a guy just saying, "What are the English courses I need to take to graduate so I can go to medical school?" It was pretty much the inverse. He was saying, "What are the science courses I need to take to go? Because these other things are also very important." .
Coronavirus Live Updates
Fauci Interviewed By NBA Star Stephen Curry On Instagram
Infectious diseases are diseases that spread among people, and that is a discipline that requires a sort of social interaction. There are some medical disciplines where you can go in and do your job. If you're a surgeon, you'll take things out and maybe you have good bedside manner and maybe you don't, but what we really care about is are you good with your hands? That's not as true with the type of doctor that Fauci is. . He certainly has said — and said to me — that the combination of the humanities and science seemed to push him towards being a certain type of physician. Because physicians are people who interpret science and deliver it to people — but they need to do it in a human way. They need to do it in a way that people understand, and I think we all know that is sometimes in short supply.
On how Fauci and his colleagues helped develop a cure for vasculitis in the '70s
Vasculitis is a very rare inflammatory disease where your blood cells attack your blood vessels and your organs shut down. And until Fauci and his mentor, Sheldon Wolff, came along, it was almost uniformly fatal. But when Fauci started working on it, he was also called to consult for cancer chemotherapy patients at the National Cancer Institute, just on their treatment — because they get very powerful [toxic drugs], and it suppresses their immune system. So doctors like Fauci were experts on the immune system, and when he saw a bunch of that, a weird thing occurred to him, which is: The vasculitis patients have overactive immune systems. Maybe if we gave them these toxic drugs, but in a much lower dose, it would lower the overreaction without killing them. And in fact, it not only did that, it cured the disease. He and his colleagues, principally Sheldon Wolff, helped cure a disease that, as he has said, it's not a disease that zillions of people have, but people died from it, and they don't die from it now.
On how activists initially blamed Fauci for the slow pace of HIV/AIDS drug trials when he became the head of NIAID in 1984
Basically, drug trials, for a long time, have undergone a particular system where you try a drug over a period of time in a small group of people who are healthy, to see if it's safe, if it has side effects, if it would harm you. Once that's done, and it can take a while, you then move to another level of testing called Phase II, where you test a small group of people to see if it's effective. Does it change the course of your disease? Are there markers in the blood system that show that it's taking effect? That takes a while. And then, if it's safe and seems to be effective, you do a much longer and bigger trial to make sure it works and that there aren't some adverse reactions that people hadn't counted on. This can take years.
Shots - Health News
Could Lessons From The Early Fight Against AIDS Inform The Coronavirus Response?
Meanwhile, [AIDS patients] had nothing. They had no hope of any treatment or cure. They were dying by the hundreds, the thousands and the tens of thousands. And they were listening to an organizations not only say, "Well, wait a few years," but they had rules like if you were on one experimental drug, you couldn't take another one in a trial. . These were absurd and outdated rules. And Fauci was the person that they knew who they could attack. It didn't matter whether he was in charge. He was the face of AIDS for the U.S. government.
On how Fauci changed his approach to the HIV/AIDS clinical trials and changed medicine
After a certain number of protests, he looked out at NIH one day as ACT UP and other protesters were storming the gates, and he thought, "These guys, they dress crazy and they say terrible things, but they're mostly from New York like I am. And let me think about this for a minute: If I had a disease in which the result was that I would die no matter what, and the government was telling me, 'You can't try anything that might work under any circumstances,' I'd be ramming down the doors, too."
In 1989, Fauci and then-U.S. Health and Human Services Secretary Louis W. Sullivan (right) announced results of studies showing that the antiviral drug AZT had delayed the onset of disease in some people with HIV. Bettmann Archive/Getty Images hide caption
In 1989, Fauci and then-U.S. Health and Human Services Secretary Louis W. Sullivan (right) announced results of studies showing that the antiviral drug AZT had delayed the onset of disease in some people with HIV.
Bettmann Archive/Getty Images
So at that point, he decided to talk to these leaders more frequently, to go up to New York and meet with them, to go to San Francisco. And he came to realize . they had a point. And even more importantly, they had some people who understood the system way better than anyone who worked for him. .
Fauci, once he understood that the activists weren't saying, "Let's get rid of the whole system,' but, [rather], 'Let's open it up a bit so that we can have some relief while we press on to get the ultimate answer.' " He said, "Jesus, that makes perfect sense." And he proposed something called "parallel track," which was these sort of two systems — the old system and the new melded in. And that's what was adopted, and it worked.
On why Fauci doesn't want to be the director of the NIH, despite his popularity and success
Fauci has been offered the head job to be the director of the National Institutes of Health — I've lost track, I think it's three times. He always turns it down. He turns it down for a couple reasons: He has a lab and he cares about keeping his lab. He cares about seeing patients, and, even now, still does. But I think more importantly, he's figured out that you can be more persuasive sometimes without having the top job — you have more room to maneuver. And I think what he values is his ability to get his point across. And sometimes when you run an organization like that, the administration is just very, very burdensome.
On how COVID-19 compares to other recent viruses
It's not as deadly as it could be. In fact, H5N1, which was usually referred to as avian influenza, was truly deadly. And if that virus had spread the way this one spread, we'd be talking millions of people [dead].
Goats and Soda
How The Novel Coronavirus And The Flu Are Alike . And Different
In 2009, we had a pandemic of influenza. H1N1 was the designation, and a lot of people called it the swine flu. One quarter of the population of Earth was infected with that virus — 1.47 billion people at the time — before any vaccine got anywhere. So that happened to be way less virulent than is usual for influenza, but had it been super bad, 10 million, 20 million, 30 million people could have easily died. Easily. And yet, we see these things come up every few years and an endless number of reports are issued saying, "We have to do more." Fauci has been screaming this song, since — I don't know, I've talked to him about it at least 10 times in the last 15 or 20 years. And he's not the only one. There are many, many people. There are so many reports and they are constantly ignored. And we've spent hundreds of billions of dollars in missile defenses in the United States. That's something that — it's not even clear it works. And we don't spend pennies on the dollar to do the same thing with viral defenses.
On the structural changes, research and bioengineering that need to happen to be prepared for the next pandemic
I think a lot of things have to happen. . There has to be someone with authority. Fauci is a guy who is a good spokesman and he can marshal facts but he doesn't go to his office every day and plan the biological future of this nation. The fact that we are surprised by biology is a tremendous failing, given what we do and what we know.
I'm hoping that maybe this pandemic, which is so ruinous, will at least make people realize that an investment . will pay tremendous dividends in terms of the safety of humanity, because this is going to happen again. There isn't any way that it won't.
I'm teaching at Stanford, and in bioengineering that's one of the things we're trying to focus on — to make sure that bioengineers and also people in this country understand that we don't have to be surprised by biology in the future. We can plan for it and we can even create what we want to create. And I'm hoping that maybe this pandemic, which is so ruinous, will at least make people realize that an investment, a few hundred billions of dollars — which sounds like a lot of money, but it's a drop in the bucket of what's happening now — will pay tremendous dividends in terms of the safety of humanity. Because this is going to happen again. There isn't any way that it won't. .
This does have everyone's attention, but so have other viruses. Not quite as much as this. But I am deeply concerned — and I'm not the only one — that what will happen is we'll get over this, and some money will be appropriated and some commissions will be formed and some words will be said, and over time, people will start to stop thinking about it. And we can't do that. We can't allow ourselves to do that, because, honestly, as bad as this one is, the next one could be worse. And also it would be irresponsible of me not to point out that the next one might not come from a bat. It may come from a crazy person who has the ability to make a virus and it's disseminated — because we are in a world where that is possible. .
We can use our ability to alter genes and rewrite biology to [cure diseases] and we don't have to wait anymore for bad things to happen to us. We should sit down and say, "What are the things we want to prevent?" and figure out ways to prevent them. It won't be perfect. It won't be 100%. There are lots of questions about how we want to deploy such powerful tools but we have those tools. We have the ability not to be shocked by biology in the future. We should be using biology — not be afraid of it.
Amy Salit and Seth Kelley produced and edited the audio of this interview. Bridget Bentz, Molly Seavy-Nesper and Deborah Franklin adapted it for the Web.