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23

The flu virus changes rapidly so that the current vaccine doesn't work against the new strains. The way vaccines work is that they teach our immune system what to look out for. The vaccine contains bits of the virus but in a form that can't cause a proper infection, the body learns what to look for and next time before the virus can really get going the ...


14

Vaccines work by introducing an attenuated strain of the pathogen (or alternatively the antigens that are normally present on the pathogens surface) into the body, whereupon the body mounts an immune response. As this will (hopefully) be the first time that the body has encountered the antigens on the pseudo-pathogen's surface, the response is called the ...


12

MBQ and Rory M have already given decent answers on the "hows" of how the vaccine memory is formed. Now, for some twists: There are three (general) types of vaccine, all of which are meant to make your body "think" its being infected and provoke an immune response, while at the same time not causing active infection. They are: Live attenuated. These ...


11

Duration of efficacy is typically determined by tracking the antibody titers of a cohort of subjects who have gotten the vaccine, and estimating based on the trajectory of those titers where they will eventually cross the threshold to the point where the vaccine no longer confers immune resistance. These estimates do get revised and estimated as time goes ...


7

The goal of the vaccine is to provoke an immune answer, therefore some degree of inflammation is expected in order for the vaccine to work. Since you get the shot intramuscularily, intradermally or subcutaneously, it is local, and the inflammation does not spread. The reason why your whole arm seems to hurt (rather than the place where the vaccine was ...


6

First let me point out that for the US, I'm not knowledgeable enough to speak for the rest of the world, you are correct. There are no approved live attenuated vaccines mixed with componet/subunit/inactivated vaccines. Background: Before we go into why that's true, let's work a little to show that's true. The FDA publishes a wonderful list of every ...


6

The major reason for this are differences in the preparation methods. Live (attenuated) vaccines need permanent cooling, which makes their use in third world countries difficult. Inactivated vaccines are inactivated either by heat, radiation of chemicals and are often freeze-dried after purification (removal of chemicals used for killing). In this ...


6

In short, some of the B-cells (antibody producing lymphocytes) specified to deal with this agent go dormant after the vaccine stimulation -- when the real danger comes, they can proliferate quickly and flood it with new antibodies, also alerting the rest of the immune system.


5

There is a Wikipedia page on the topic of attenuated vaccines. Basically the idea is that the virus is grown on some sort of foreign host such as cells in culture, eggs or an animal. This selects for mutant viruses, present in the original population, which are pre-adapted to the new host (so that they grow better). By repeating this process several times ...


4

No, it is not true, see references 1 and 2 for this purpose. From these articles which followed up booster vaccinations for pertussis it seems that there is at least some protection 5 and 8 years after the boost. There is another study, which says that 10 years are relatively safe to assume, as the reduction in antibody levels over time estimated from the ...


4

There are basically three classical possibilies: Using an attenuated virus as Alan described in his answer use only parts of viruses (here mostly proteins, which are displayed on the surface of the virus and which can be recognized by the immune system) inactivated viruses (here often formaldehyde is used, which changes parts of the proteins, the ...


3

Not true. Vaccines were initially made for the highly contagious diseases that used to cause epidemics (which obviously means they were not rare). The efficacy of a vaccine depends on multiple factors which includes adaptability of the pathogen. The all-the-time encountered pathogen that the article is talking about is HIV; the reason for why no ...


3

What you call influenza isn't a specific virus which is always the same, but a virus that has numerous different strains. Flu virus is constantly alive on this planet, and there are numerous different types, such as the ones which infect humans, the ones that infect birds, and occasionally a virus that mutates to infect humans although it shouldn't as it ...


3

Remember first that the human body nearly always, although there are exceptions, rejects any non-genetically identical graft placed into it, and therefore one cannot prepare a general colony of B-cells to confer immunity to the population at large. However, in principle, there is no impediment to removing B-cell progenitors in an individual, conditioning ...


3

The toxins of both Clostridium tetani and Corynebacterium diphtheriae are so toxic that you cannot use them for immunization, since the amount needed for proper antibody production would kill the individuals. For that purpose the toxins are "de-toxified" by reacting them with formaldehyde which takes away the toxicity but the resulting toxoids are still ...


2

But are there ways to tell the body that this allergy is safe and there is no need to amount a response to it? Yes, that's what allergy shots (Exposure Therapy) does. Exposure Therapy is an effective, albeit sometimes imperfect, method of letting the body know that a substance is common and that it shouldn't mount a response to it. Over time the body ...


2

Ovalbumin is frequently used in immunology to induce an immune response (see some publications about mice and ovalbumin here. You usually inject it together with an adjuvans to enhance the reaction. The factors that must be taken into account for its maintainance are the same as for the other antigens, so you should boost this "vaccination" from time to ...


2

Not an easy question, especially since the reasons for both pathogens are different. For HIV the problems are manyfold: Insufficient knowledge about required immunity Its not known, which parameters are really important to raise an adequate immunity. Variation in HIV strains HIV has a very high mutation rate, which results in many different ...


2

Rhinitis is irritation and inflammation of the mucous membrane inside the nose. Common symptoms of rhinitis are a stuffy nose, runny nose, and post-nasal drip. The most common kind of rhinitis is allergic rhinitis, which is usually triggered by airborne allergens such as pollen and dander [1]. Many questions regarding sublingual immunization still remain to ...


2

The source article had several major errors in it. I wouldn't trust any of it. Vaccines are designed to protect against invaders that are encountered rarely - not all the time. This is one of the major errors. There is a vaccine for chicken pox now - an infection which affected approximately 4,000,000 cases per year in the US before the vaccine. That ...


2

The exposure to environentally occurring Mycobacteria causes a immune response to these (mostly unspecific, since no real infections occur). It seems that immunizations with BCG in these individuals is causing either no, or only a very attenuated immune response This is shown in this ("BCG-induced increase in interferon-gamma response to mycobacterial ...


2

Interesting question! The Tick Borne encephalitis vaccine is an inactivated vaccine. It is therefore impossible to get the infection from the vaccine. Reports of fever have been noted but that is due to the body mounting an immune response not due to infection. There are therefore no reports of encephalitis or other markers of infection following the ...


1

According to Wikipedia in 1998 a vaccine was approved by the FDA. It was directed against the outer surface protein A (OspA) of B. burgdorferi, but was taken from the market in 2002 after a large number of recipients reported the development of autoimmune diseases. An investigation of the FDA and the CDC found no connection to these claims, but afterwards ...


1

There is also some work with programming a patients own stem cells to become long lived plasma blasts for broadly neutralizing antibodies against HIV (and other diseases I assume). Although you are essentially asking what is harder...eliciting these broadly neutralizing antibodies with traditional vaccine approaches (difficult), or working out the complex ...



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