49
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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;...
- 9,024
41
votes
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Why is it advised that infants are fed mother's milk?
The phrase "Breast is best" is a hotly debated one (source: The Guardian and personal communications with many folks). The reason why we don't want to feed infants cow's milk is, however, anything but ...
- 52.3k
38
votes
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Why are scientists saying that the Omicron COVID-19 variant is 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 ...
- 44k
30
votes
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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
...
- 44k
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 ...
- 51.5k
25
votes
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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 ...
- 373
20
votes
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Why does immunity from the flu vaccine appear only after two weeks?
Most information here can be found broadly in Cellular and Molecular Immunology, 8th Ed.
Here's how the flu vaccine works: Scientists forecast months in advance which strains they think stand to ...
- 8,101
18
votes
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Why is an HIV infection considered "incurable"?
The reasons why HIV is "incurable" (a misnomer) are legion:
HIV is a retrovirus, which means it inserts its own genome into the host cell's genome. You must therefore kill each and every infected ...
- 9,681
18
votes
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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 ...
- 5,324
17
votes
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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 ...
- 14.2k
16
votes
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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 ...
- 14.2k
16
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 ...
- 3,666
15
votes
Accepted
Can people with AIDS get a fever?
With AIDS, the whole immune system is not non-functional. The condition results in a severe drop in CD4+ T-cells, which is what primarily predisposes AIDS patients to secondary infections.
Fever can ...
- 2,472
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 ...
- 8,256
14
votes
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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,
...
- 3,666
14
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Why are scientists saying that the Omicron COVID-19 variant is 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
13
votes
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Why do people dying of immune deficiency diseases appear sick?
Many of the symptoms of disease are indeed related to inflammation, but inflammation depends heavily (though not solely) on the innate immune response. Patients with AIDS and some of the other ...
- 14.2k
12
votes
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What will happen if a foetus is Rh- and the mother is Rh+?
Nothing. Rhesus incompatibility results when people who are Rh- develop antibodies against Rh+ blood after exposure. People with Rh+ blood do not show any such reaction to Rh- blood.
In a way, it's ...
- 2,258
12
votes
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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 ...
- 2,380
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. ...
- 51.5k
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
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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
11
votes
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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 ...
- 11.2k
10
votes
What are the difficulties/challenges against developing a coronavirus vaccine?
Vaccine development is not as easy as just inject some inactivated virus as:
Vaccine can have side effects such as inflammatory reactions. So for a good vaccine the side effects must be negligible ...
- 2,659
9
votes
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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 ...
- 3,667
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 ...
- 827
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 ...
- 52.3k
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 ...
- 8,751
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