Questions tagged [virology]

Virology deals with the study of viruses, infectious entities that require the machinery of a host cell to replicate.

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53
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7answers
10k views

Why isn't a virus “alive”?

The recent news about a new supermassive virus being discovered got me thinking about how we define viruses as non-living organisms whilst they are bigger than bacteria, and much more complex than we ...
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5answers
8k views

Virus cannot survive on surface after certain time period, but why and how?

I'm not a biology student at all, but I'm trying to get a clearer picture on what is meant by "virus cannot survive after a certain period". To my understanding, a virus cannot be killed it can only ...
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2answers
532 views

Changing the definition of life?

Viruses at this period of time do not fit the current definition of life. Much of the reasoning behind this is that we currently believe that all life must be made up of cells. Also, many biologist/...
38
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2answers
45k views

Why don't we develop immunity against common cold?

We all suffer from common cold, and that, frequently. Why have we not developed immunity against it till now? By immunity I mean immunity as a species.
25
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1answer
1k views

What are the environmental conditions for SARS-CoV-2 to survive?

What do we know about the environmental limits for nCoV to survive outside the body? For example, in: In open air On surfaces In water What are the limits for temperature, humidity and air pressure,...
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3answers
11k views

What causes a 'stuffy' or 'runny' nose when you have a cold?

When humans get the common cold, a common symptom is a stuffy or runny nose. Is that the body's immune response or is that the virus's doing?
32
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1answer
1k views

How did viruses come to be?

My question is out of curiosity and got me thinking. How did viruses with the head, tail and tail fibres actually evolve? These viruses look more like machines than biological entities. Are there any ...
16
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5answers
2k views

Why have parasites not evolved to be harmless?

I have yet to understand why so many viruses or bacteria haven't evolved to be harmless (specifically, I don't know of any harmless virus). I think it would be greatly beneficial for a virus to ...
13
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3answers
2k views

Are viruses self-propelled?

So obviously, viruses are nonliving. But when my teacher was teaching viruses in the video (we're doing "flip" learning this semester), the way he described it, it seemed like the viruses responded to ...
12
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2answers
654 views

Why are bats the source of dangerous coronavirus pandemics?

Why do coronaviruses come from bats? I mean, why precisely coronaviruses and not (for instance) herpesviruses? It looks like bats host more zoonotic viruses (per species) than rodents, although they ...
10
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2answers
5k views

How exactly does alcohol solution kill or neutralize viruses?

To reduce the risk of infection by viruses (including 2019-nCoV) the CDC suggests: Wash your hands often with soap and water for at least 20 seconds. Use an alcohol-based hand sanitizer that contains ...
7
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1answer
6k views

What is the size (diameter) of the SARS-CoV-2 virus?

You can easily find a lot of pictures of the SARS-CoV-2 virus. But although it should be trivial for an electron microscope to measure the size, I am not able to ...
95
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3answers
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What's the evidence against SARS-CoV-2 being engineered by humans?

A couple of colleagues suggested in a discussion that the virus that causes COVID-19 appears to be made by humans, since nature could not have produced such an efficient virus — that spreads so fast ...
44
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3answers
23k views

How does a Coronavirus “test kit” work?

A number of countries are using test kits for detecting new cases of nCoV (2019-Coronavirus) and apparently China is running low. What exactly is in a nCoV "Test Kit" — How does it work? (Surely ...
32
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2answers
3k views

Why doesn't blood remain on a mosquito's proboscis in quantities that could spread blood-borne diseases?

We know that HIV can't be transmitted by mosquitos, and nor can other highly virulent viruses that are transmitted through blood and bodily fluid exchanges, such as Ebola (thankfully!). Marcus Junius ...
28
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2answers
7k views

Why is rabies incurable?

I'm still not sure about the mechanics that lead to rabies being incurable. I know that it can be treated before any symptoms show up, but why is it that once symptoms show the person is a dead man ...
9
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2answers
333 views

How do bats survive their own coronaviruses?

How do bats survive their own coronaviruses (without showing any symptoms)? Or, more generically, how can viruses keep reproducing inside healthy carriers without inducing any pathogenic effect? Are ...
7
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2answers
571 views

Viruses: Adaptation to a new host through repeated host jumps

A friend told me, during a 3 minute discussion, that viruses that are endemic in host $A$ and make repeated jumps to host $B$ but can't be transmitted between individuals of species $B$, may slowly ...
11
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2answers
9k views

Why do I need a flu shot every year, while many other vaccinations last years or even a lifetime?

Is it a viral vs. bacterial thing? Is there just more variety among types of flu than other diseases, so that this year's vaccines don't cover next year's flu?
8
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2answers
3k views

How does the ebola virus attack?

How does the ebola virus attack and how do some people get away with it? Normally any virus would attack a cell with some kind of receptors and some kind of lock and key mechanism entering the cell ...
7
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1answer
153 views

What is the purpose of getting a rabies vaccine after exposure?

After exposure to the virus, it is already inside you and your immune system will start to recognize it. Is the vaccine then just a way to kickstart this process so the body can fight off the ...
6
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1answer
113 views

Do any known viruses contain “junk” or parasitic genomic information?

After reading about so-called "mystery proteins" in this excellent summary of the coronavirus genome (and acknowledging that the "mystery" simply reflects our lack of knowledge about a very new virus),...
7
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1answer
370 views

How exactly can dsRNA be introduced to a cell?

Is it just by viruses or are there other means by which it gets into cells, such as plasmid uptake?
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5answers
7k views

How does HIV mutate into other strains while keeping their virulent phenotype?

How does a virus like HIV mutate into so many strains, and yet all of them are harmful to our immune system? What gives this virus the ability to mutate so efficiently?
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2answers
380 views

Agony, Hydrophobia and viruses in the light of evolutionary principles

I'm undergraduate physics student, but I've always been interested in biology. So I have a couple of questions about an application of the evolutionary principles to practice. Agony as the last stage ...
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0answers
131 views

How do viruses die outside of host cells? [duplicate]

I am posting a question that a friend of mine has asked. My friend wrongly assumes that SARS-CoV-2 virus can be transmitted through blood, although there is no such evidence. However, his question ...
96
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7answers
22k views

Do beneficial viruses exist? If so, what examples are there?

Typically, people call viruses some kind of organic compounds that cannot reproduce autonomously and which lower the fitness of their hosts. Even the word "virus" means "venom" in Latin. But from the ...
28
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3answers
8k views

Can the dead be brought back to life by viruses?

Zombies have been a part of popular culture for decades. The living dead rising up to take over the world is a terrifying concept, worthy of Hollywood blockbusters and television hits. Some of those ...
57
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2answers
12k views

Are the social-distancing measures implemented against SARS-CoV-2 also suppressing the spread of other viruses?

With social-distancing measures being implemented in many countries I would expect other viruses, like the ones that cause seasonal flus, to have also a hard time propagating in these circumstances. ...
2
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1answer
296 views

Is Covid-19 likely to mutate into a deadlier form?

When the Spanish influenza hit in 1918, it struck in two waves. The first wave was typical for a flu virus, targetting mainly elderly people, but the second wave was far deadlier and killed far more ...
17
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1answer
678 views

How does herpes (HSV) infection suppress HIV?

HIV compromises the human body to defend against infection. Yet people who are infected with herpes are at less risk of developing AIDS. How does this work?
16
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2answers
59k views

Why does rabies cause hydrophobia?

What feature of rabies pathophysiology causes hydrophobia? Why is hydrophobia unique to this one particular type of viral infection?
15
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1answer
3k views

Why do viruses last longer on hard surfaces, like glass, than porous ones

All the papers I've read about survival of viruses outside of the host refer to longer survival times on hard surfaces without explaination. As a layman I would have thought that a virus (who's main ...
10
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2answers
2k views

Why Can't The Immune Systems of Uncontacted Tribes Handle Our Common Colds?

I'm sorry if this is a stupid question, I'm just starting my first year of a biomedicine degree and I'm curious - googling didn't find me any answers. I know that the Aboriginal Australians and many ...
9
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1answer
868 views

Is COVID-19 claimed to get less deadly over time? If so, why?

From a TV news report of a press conference from (I think) the German Robert Koch Institute, I remember hearing an expert declare that he was expecting COVID-19 to get less deadly over time. ...
9
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3answers
183 views

Why does increased humidity decrease coronavirus “survival”?

All news I can see scientist telling that the SARS-CoV-2 virus survive more in cold and dry weather. I can understand cold as hot weather will desiccate virus, but why dry weather. Would not dry ...
5
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1answer
998 views

What is the name of the category of viruses that affect only one side of the body?

The Varicella zoster virus causes chickenpox in children and shingles in adults. When the virus attacks as shingles, one of its distinguishing characteristics is that it only affects one side of the ...
4
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0answers
208 views

What percentage of cells in the human body are infected during a non-fatal viral infection?

I understand that this would be a very rough estimate, but approximately how many cells in the human body are infected during an average non-fatal viral infection before the infection is eliminated by ...
2
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3answers
9k views

How do viruses or bacteria survive outside the body long enough to spread?

Say I cough on my table, then someone else touches it and picks up something I've got... how is it that these things can live outside the body, how long can they manage it, and how long is generally '...
14
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1answer
1k views

How heavy are all foreign microorganisms in and on the human body?

I define "foreign microorganism" as a microorganism which is not produced by the human body (not antibodies or leukocytes) including bacteria, viruses, fungi, biofilm aggregates or small lifeforms ...
4
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2answers
6k views

How long do viruses, such as Zika, stay in the body?

Can a virus stay in your body (after recovery) in a concentration that is sufficient to infect someone? Is it known how long the Zika virus persists in the body?
2
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1answer
241 views

We know that the hepatitis C virus can live on surfaces for at least six weeks. Maybe longer. The infectivity study ended after just six weeks; why?

Background A paper has found that the hepatitis C virus (HCV) can remain infective for at least six weeks on ordinary household surfaces. You can see the free full text, or a summary for busy ...
2
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1answer
143 views

Can Covid-19 (similarly to HIV) infect T-Cells?

I'm interested in better understanding this Nature publication, discussing the potential for Covid to infect t-cells. After describing the results they conclude: "Based on the results of pseudovirus ...
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2answers
96 views

Why does the SARS-CoV2 virus not remain infectious forever? Or does it?

Given that the majority of biologists do not currently consider viruses to be alive, a virus can never die. It can, however, get destroyed by long exposures to soapy water, alcohol, and apparently ...
9
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2answers
14k views

What is the life cycle of a wart?

There doesn't seem to be a lot of information available on research done on warts. What is the life cycle of a wart? How does it spread? -- specifically how does it recruit cells to spread it? What ...
7
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2answers
469 views

Why are some viruses not communicable person-to-person?

Below are two quotes from the CDC about Hantavirus: "Researchers believe that people may be able to get the virus if they touch something that has been contaminated with rodent urine, droppings,...
2
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2answers
131 views

What's the difference between mutation and substitution rates?

The Wikipedia section on substitution rates (shown below) isn't clear to me. What's the precise definition and difference between mutation and substitution rates, and how do they relate to each other? ...
2
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1answer
115 views

Viral mutation rates and replication

TL;DR What's the relationship between the following? Mutation rates (expressed as "mutations per year" for a virus like e.g. COVID-19 (SARS-CoV-2). E.g. this article mentions "The rate ...
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1answer
141 views

Since RNA viruses and retroviruses all have high mutation rates, why do only a few viruses have the virtue of variability?

We have been taught that it's difficult to make vaccines to influenza, HIV and HCV because they lack the proofreading mechanism, hence have high mutation rates. But most RNA viruses and retroviruses ...
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2answers
112 views

In marine DNA viral diversity studies, what would “paradigm of rampant mosaicism” refer to?

The recent paper in Cell Marine DNA Viral Macro- and Microdiversity from Pole to Pole describes the (huge) new Global Ocean Viromes 2.0 (GOV 2.0) dataset. In the Results and Discussion section, the ...