49
votes
Accepted
Why is untreated trypanosomiasis invariably fatal in humans?
African trypanosomiasis, or sleeping sickness, is caused by the protozoan Trypanosoma brucei, a single-celled eukaryote. Being eukaryotic, it has a cell nucleus and a larger genome than most bacteria;...
- 9,083
39
votes
Accepted
Why did scientists state that the Omicron COVID-19 variant was a reason to get a booster?
(note: I'm simplifying things a bit here by only talking about antibodies; I don't mean to downplay other aspects of the immune response, just to keep it focused for a lay audience)
Natural antibody ...
- 46.5k
31
votes
Accepted
What does vaccine efficacy mean?
Vaccine efficacy
Pfizer's target measures for efficacy (see the study on clinicaltrials.gov) seem to be:
Confirmed COVID-19 in Phase 2/3 participants without evidence of infection before vaccination
...
- 46.5k
29
votes
Are fully vaccinated people more likely to not get infected at all with COVID-19?
Yes, this is the effect of the vaccine. A reduction of infections of over 88%, a reduction of severe cases and death by 95% and higher. See reference 1 for the details. Data from the ReCoVAM Study ...
- 52.5k
25
votes
Accepted
Can fever cure Ebola disease?
Short Answer: Fever cannot cure Ebola simply because the virus is not temperature-sensitive.
Background: Fever is a defense mechanism of the body which is specific to temperature-sensitive virus and ...
- 14.1k
25
votes
Can simultaneous double pathogen infections happen, or are they prevented?
You can absolutely have two infections occurring together.
One term which is used is 'co-infection'. Also 'secondary infection', in case where either the first infection or the treatment made it more ...
- 372
18
votes
Accepted
Is COVID-19 claimed to get less deadly over time? If so, why?
While the data are much too sparse and noisy to give an answer about what is happening to COVID-19's virulence (the technical term for the "deadliness" of an infectious disease), or to forecast what ...
- 5,504
17
votes
Accepted
Why doesn't our immune system react to infused antibodies produced in a horse?
Our immune system does react to horse antibodies, but as with any adaptive immune response it takes some time for the response to develop. In the weeks before our immune response fully responds to the ...
- 14.3k
17
votes
Accepted
How do bats survive their own coronaviruses?
It's common for the reservoir host of a zoonotic virus to be tolerant of it. MERS coronavirus appears to cause mild or no disease in dromedary camels ( source ), but kills about 35% of confirmed ...
- 3,949
16
votes
Accepted
What is the purpose of getting a rabies vaccine after exposure?
Rabies virus enters the body, typically from a bite, and then enters nerves which it follows up to the brain. An immune response to a first exposure of a pathogen generally takes many days, perhaps ...
- 14.3k
15
votes
Do spike-protein-based vaccines undermine the DNA repair system?
Note: in the time since writing my answer, the paper in question has been retracted. Here's the text of the retraction notice provided by MDPI in collaboration with the authors:
The published article ...
- 8,326
14
votes
Accepted
Septic Shock: I'll kill myself before you kill me
The important thing to recognize about the host response to sepsis is that it is actually a generalization of mechanisms used in local infection response by the innate immune system. When an animal ...
- 256
14
votes
Do spike-protein-based vaccines undermine the DNA repair system?
The authors explicitly suggest the first part of your question in their discussion section:
indicating that full–length spike–based vaccines may inhibit the recombination of V(D)J in B cells,
...
- 3,949
14
votes
Why did scientists state that the Omicron COVID-19 variant was a reason to get a booster?
Some Clarification:
Scientist were not opposed to a third dose, they were opposed to the rich country getting a third dose before we vaccinated the rest of the world. The WHO is right to call a ...
- 251
12
votes
Accepted
Why are there 2 copies of RNA in the HIV virion?
You are not totally correct because these two strands don't have to be the same, they can be genotypically different, which occurs when a cell is infected by two distinct HIV strains. Also HIV uses ...
- 2,410
12
votes
What does vaccine efficacy mean?
It means protection against the virus brought to you by the vaccination.
Around 45.000 people participate in the trial; 50% of these are vaccinated with the trial vaccine and 50% receive a placebo. ...
- 52.5k
11
votes
Accepted
Is vermiform appendix no more a vestigial organ?
Short Answer: No, the appendix is still considered a vestigial organ.
Long Answer: The idea that that vermiform appendix is vestigial originated when Kumar et al (1989) removed it from the body, but ...
- 14.1k
11
votes
Accepted
What are the difficulties/challenges against developing a coronavirus vaccine?
There are multiple challenges presented, and many of those are not limited to coronavirus vaccine.
As mentioned above, it just takes time. Before a vaccine can be used in patients, clinical trials ...
- 150
10
votes
How do bats survive their own coronaviruses?
It's been tentatively proposed that bats are often unusually able to tolerate long-term infection with a wide range of viruses (though this hasn't been formally shown to be true). A specific cause for ...
- 14.3k
10
votes
Accepted
Can the Monkeypox virus be spread by mosquitoes?
As yet there are unlikely to have been any studies looking at this particular scenario with Monkeypox virus, as it hasn't been widely studied.
However, the poxviridae are all similar in that they are ...
- 12.9k
9
votes
Accepted
Is an antivenom venomous?
Although it is fancy to think of antivenom as a poison for the poison, technically it is a poison only for the poison!
Antivenom is developed in horses (equine) by hyperimmunizing them against the ...
- 3,687
9
votes
Accepted
What is the rationale behind tapering of immunosuppressant dose a while after transplant?
This is a very interesting question. One of the most important considerations in patients on long-term immunosuppression is the risk of complications, whether infections or (more dangerously) cancer ...
- 837
9
votes
Is vermiform appendix no more a vestigial organ?
Short answer
The appendix is a vestigial organ.
Background
According to the Oxford Dictionaries vestigial means:
Degenerate, rudimentary, or atrophied, having become function-less in the course ...
- 52.6k
9
votes
Infant immunization
There are a wide variety of different kinds of vaccines. The basic principle is that the human (and more generally, jawed vertebrate) immune system can identify invaders by recognizing and responding ...
- 8,811
9
votes
Accepted
Can people with AIDS/HIV be vaccinated?
Can people with AIDS/HIV be vaccinated?
Yes. Immunization is an important part of the overall treatment strategy for HIV positive individuals. HIV infection is a risk factor for a number of vaccine ...
- 8,811
8
votes
Accepted
Are MHC Proteins the Most Polymorphic Human Proteins Known?
Yes. There are many MHC (MHC in humans is called HLA) genes. The classical loci — Class I A, B, and C, and Class II DP, DQ, and DR — are the most polymorphic.
Here's a table from a 2002 article ...
- 9,701
8
votes
Accepted
Why don't we build up an immunity to sore throat?
Short Answer
It should be noted that there are many non-pathogenic causes of sore throat, and I would suspect that you are not always distinguishing these causes from actual illness.
In most cases, ...
- 30.3k
8
votes
what if there is a door for which our immune system has no key?
The Native Americans and smallpox
First I want to note that some of the posted answers are not quite accurate. For example, smallpox ravaged the Native American population because they did not have ...
- 81
8
votes
What is the mechanism by which passive immunity works?
I commented on this question, but the OP's response prompted me to think again. Here is the graph from the document that the OP linked to:
Clearly what is confusing is that the parameter referred to ...
- 22.8k
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