Questions tagged [immunology]

The study of the immune system in organisms, primarily responsible for fighting infection.

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38
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2answers
42k 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.
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1answer
130k views

Why do vaccines cause your arm to hurt?

When you get a shot for a vaccine (for example, the annual flu vaccine), the nurse frequently indicates that your arm will ache for a day or two, maybe more. This ache is typically not just a pain ...
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2answers
242 views

How is duration of efficacy estimated for vaccines?

Vaccines, especially those given in adulthood, usually have term limits attached, eg: 10 years for yellow fever or 3 years for typhoid. Since presumably the time course of an immune response is no ...
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2answers
4k views

Why is it advised that infants are fed mother's milk?

I have heard that mother's milk is preferred over other baby foods, because it contains immunoglobulins (secretory IgA), and other essential nutrients. But why is mother's milk so special? Any ...
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4answers
7k views

How does the immune system “learn” from a vaccine?

According to Wikipedia: A vaccine typically contains an agent that resembles a disease-causing microorganism, and is often made from weakened or killed forms of the microbe, its toxins or one ...
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2answers
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Harmless virus?

Is it possible for a virus to live symbiotically with its host? Is the human body plagued with viral infections that do negligible harm, or even serve a beneficial role?
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Why do people have antibodies against other blood types?

The ABO blood type divides each blood type according to whether they have the "A" and "B" antigen(s) (AB has both, O has none). People also have antibodies against the antigens they don't have (AB has ...
22
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1answer
787 views

Are lymphocyte sizes clustered in two groups?

Tortora writes in Principles of Anatomy and Physiology: Lymphocytes may be as small as 6–9 μm in diameter or as large as 10–14 μm in diameter. Those ranges are quite close to each others. Should ...
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1answer
2k views

How Do White Blood Cells Learn? Or Do They?

So I get the concept that a vaccine is a weakened form of a virus so that the body can "learn" to fight it and make a person immune to that disease, but how exactly does this learning take place? What ...
17
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553 views

Why do people dying of immune deficiency diseases appear sick?

Please forgive the obviously silly appearance of this question, and/or of the tenor which may come across as flippant or dismissive of real world suffering. My intention is none of the above. As a ...
17
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2answers
195 views

What are the main mechanisms of interaction between the nervous and immune systems?

We know from pop science that our psychological states have an effect on our immune systems ("worrying ourselves sick", etc.), but what are the actual mechanisms through which our nervous systems pass ...
17
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1answer
2k views

Why are there 2 copies of RNA in the HIV virion?

There are two copies of the RNA in the HIV virion. These are retroviruses. So, they can make cDNA from even just one copy using reverse transcriptase. What is the use of the other? Are both ...
17
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1answer
4k views

Do we actually get more sick (flu/cold) during winter?

The word flu derives from the Italian phrase "influenza de freddo" meaning "influence of the cold". Indeed it is that time of the year when my colleagues seem to have the flu/cold more often than not....
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1answer
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At what age do babies begin to synthesize their own antibodies?

When babies are first born, they receive their antibodies from their mother (I assume because they do not yet have the capacity to synthesize their own). So my question is, at what age do babies ...
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1answer
628 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?
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7k views

Why does immunity from the flu vaccine appear only after two weeks?

It is said that immunity from a flu vaccine appears after about two weeks. However, from experience, the flu usually lasts only a few days. If sufficient antibodies appear only after two weeks ...
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2answers
2k views

What is the smallest molecule that can present as an antigen to the immune system in the context of allergies?

People often claim, in a colloquial sense, that they are "allergic to everything". Is it possible to have a full-fledged IgE mediated allergic response to very small molecules? I was always under ...
14
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1answer
268 views

Organ cloning - possible to make a non-antigenic organ?

From a J. Neil Schulman article on Organ Cloning: Cannibalizing organs from other people also entails the risk of rejection because of incompatibilities, not only for tissue-typing but also for ...
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3answers
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Is vermiform appendix no more a vestigial organ?

The appendix has a role in the immune response. So is it therefore recently removed from the list of vestigial organs?
13
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1answer
289 views

Why do doctors still advise HIV+ couples to wear a condom during sex?

HIV infected people already have HIV, but why do doctors still advise condom use for HIV+ couples?
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1k views

If all B cells are present at birth, why should the primary response to an infection take longer than the secondary response?

When learning about the immune response, my teacher mentioned that all the bodies B cells are present at birth, and there is one to counter every disease. But if this is the case, why should the ...
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1answer
1k views

Why are people unable to develop lasting immunity against Norovirus?

Infection with many viruses will result in decades-long if not lifetime immunity, for example chicken pox. Because of the large number of viruses responsible for the common cold, lifelong immunity to ...
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2answers
2k views

Why does the protection afforded by some vaccines last longer than for others?

After reading an answer to the question of How Do White Blood Cells Learn? Or Do They?, I came to wonder something. Specifically, The effect of this is that every new B and T cell that your bone ...
12
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1answer
849 views

In which order did the cells of the immune system evolve?

Thinking about how complex the interactions between different types of immune system cells (T-helpers, T-Killers, Phagocytes, B-Cells etc.) are, it's fascinating how they all combine to get the ...
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1answer
3k views

If fever is a natural immune defense, why do people take drugs to lower it?

If fever is a natural defense against pathogens, why do sick people take NSAIDs to reduce the fever?
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5k views

Why is an HIV infection considered “incurable”?

My biology teacher told me that if one caught HIV, they cannot be cured because it was near to impossible to be completely virus-free. She said this was because HIV keeps on changing its glycoprotein ...
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2answers
1k views

Do antibiotics attenuate immune response on subsequent exposure to same bacteria?

A healthy immune response to a bacterial infection includes "memory" to permit the body to thwart subsequent exposure to same bacteria. What are the dynamics of using antibiotics on initial exposure ...
11
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550 views

If Tumors have lots of mutations in them how is it the immune system can't detect them?

If a cancerous tumor has a lot of mutations in them why can't the immune system detect them? If a person has cancer could this somehow alter the person's immune system so it doesn't function ...
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1answer
398 views

What prevents a pregnant woman's immune system from recognizing her fetus as nonself (and attacking)?

I'm familiar with the scenario of Rh- mother with Rh+ fetus having complications (more so after her first child), but that's not what I'm curious about. I want to know mechanistically why a pregnant ...
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2answers
7k views

Is there a maximum amount of antibodies your body can keep?

I am wondering if you were theoretically able to get vaccinations or antibodies for any and every diseases and/or illness, would there be a limit to how many you can get and keep in your body at one ...
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2answers
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Why doesn't our immune system react to infused antibodies produced in a horse?

Calmette tried injecting horses with snake venom and then taking out the serum which has produced antibodies against the venom and injecting in the snake-bitten human. Shouldn't our immune system ...
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1answer
306 views

Septic Shock: I'll kill myself before you kill me

Most of the deaths caused by extracellular bacteria don't actually result directly form their action. Rather, it results from an overreaction of the immune system to antigens such as LPS and LTA (...
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1answer
782 views

What is the rationale behind tapering of immunosuppressant dose a while after transplant?

MMF, Cyclosporine, Prednisolone, Tacrolimus the dose of whatever immunosuppressant used is reduced in around 6 months - 1 year after the transplant. What is the rationale behind this? Wouldn't any ...
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Why do dendritic cells have CD4/CD8 on their surface?

Why do dendritic cells have CD4 or CD8 antigens on their surface? What is their function without the presence of a T-cell receptor?
10
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1answer
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Why is there an extended delay before G.M. liver cells are attacked by the immune system?

In this BBC article a trial is described where patients with B-Haemophillia are infected with modified Adeno-associated Virus 8 which contained the genes for Factor IX clotting protein. Trials seemed ...
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What is the distinction between chemokines, cytokines, interferons and interleukins?

They all seem to describe molecules of similar function and many people seem to use them interchangeably. Also please include any other similar molecules if I've forgotten any in the list above.
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3answers
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How and when did a dedicated immune system evolve?

I have recently been doing a lot of research into the interplay between the innate and adaptive immune systems in humans, and mammalian laboratory models. This has led to my reading some interesting ...
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1answer
159 views

Using the IMGT/GENE-DB service to find RSS

I'm trying to get the data for the Human and Mouse 12 and 23 Recomination Signal Sequences (RSS), to run a classification algorithm on it. I'm not a biologist, so I apologise in advance for my ...
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2answers
13k views

Reasons why people say that AIDS/HIV doesn't exist

It's been recurrent when I hear people saying that AIDS doesn't exist. When I ask why, they give weird reasons like HIV is a virus created to control economy and to develop medicine, etc. Also when I ...
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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?
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1answer
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Why can blood group O be given to all blood groups?

The blood of persons of blood group O contains antibodies against antigens A and B. The red blood cells of persons of blood group A have A antigen on their surface. If someone with blood group A ...
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1answer
775 views

Can people with AIDS get a fever?

It's my understanding that fevers are an immune system response to infection. Like the body's cells can take more heat than most viruses or bacteria. So if that's the case then can you even get a ...
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1answer
4k views

What will happen if a foetus is Rh- and the mother is Rh+?

If a mother has Rh-negative blood and her foetus has Rh-positive blood it will result in rhesus incompatibility and lead to erythroblastosis fetalis. What will happen if the reverse occurs, when a ...
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2answers
518 views

How are antibodies designed?

Antibodies have the ability of recognising highly specific peptide sequences and bind it at their antigen-binding site. This ability is harnessed as a tool in research to purify target structures in ...
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1answer
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Why some parts of the human body have immune privilege?

Why have the eye and CNS have immune privilege? Why does the body not develop tolerance against their tissue and instead risk their damage in case an accidental immune cell infiltration? Wiki: ......
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2answers
317 views

Why it is important to vaccinate a human newborn within 24 hours since birth?

In Poland a newborn has to be vaccinated within 24 hours against hepatitis B and tuberculosis. As I understand it is good to be vaccinated against both, I do not see the need to hurry so much. ...
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2answers
255 views

How do we find antibiotics?

So the last class of antibiotics were made in 1984 (I think), which makes it appear as though they are hard to find(/design maybe). How is it then they were discovered? Was it by chance? I know some ...
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3answers
15k views

Presence of MHC on red blood cells

Do red blood cells have no MHC? (I have often heard that they do not.) If so why are they not destroyed by immune cells?
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1answer
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What are the clotting factors' effect on avascular necrosis development?

Do clotting factors tpa and pai-1 lead to degenerative osteoarthritis in the same way that lupus anticoagulant and prothrombin might? Is one of these pathways particularly detrimental during formation ...
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Multi-nucleated cells: advantages and examples?

This question arises because I saw that monocytes and leukocytes are commonly called 'mononuclear cells' in the scientific literature. The implication of course being that other immune sub-types are ...