What are vaccines? How does it work in the body?

So im curious to learn about vaccines. I just got one for hpv and the flue... How exactly does it work? Do they inject the dead virus itself?

2 Answers

  • 7 years ago
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    @Some random guy, it's flu. A flue is part of a chimney. Flu is an abbreviation of influenza. Luis, I'd be more than happy to explain vaccinations.

    "How exactly does it work?" -- The whole point of a vaccination is to stimulate the immune system into producing enough antibodies against an organism so that one has immunity. The initial antibodies are IgM and these are temporary, the long-term antibodies are IgG. I'll get back to these in a bit.

    When you get vaccinated, you're receiving a small amount of the organism along with the more important part, antigens. Viruses and bacteria have a protein, called antigen, on their surface. It acts kind of like an ID badge, and identifies the bacteria or virus as not belonging to you, or "non-self" as we call it. Your body makes something like 200,000 or so different proteins and some end up on the surface of your body cells, including blood cells. And like an ID badge, these surface antigens identify these cells as being "self". So when you receive a vaccine, and I'll address specifically flu vaccines for this, you're getting either inactivated viral particles with antigen (injected) or attenuated virus with antigen (intranasal). I'll explain this in more detail when I answer your second question.

    Your immune system won't recognize the viral antigen as being "self" and will react. Much of the immune response causes the unpleasant symptoms we have when we're sick. It's not the virus causing this, well, indirectly it is. But directly, it's the immune system. The immune system produces a number of chemicals (chemokines & cytokines) that cause fever (pyrogens), body aches and pain (prostaglandins), swelling (histamine & inflammatory response) and more. Some things we feel, for example dizziness and lightheadedness, can be caused by increased mucus production in the airways and the inflammatory response creating congestion, constriction and reduced oxygen intake.

    The immune system first produces an antibody called immunoglobulin M, or IgM. I mentioned that IgMs don't last long, that they're temporary. Later on another kind of immunoglobulin is produced, called IgG and this hangs around in the blood for a long time, years even. So...the immune system responds not to the presence of viruses or bacteria but to their antigens. In the case of some bacteria, those that produce toxins, the immune system reacts to the toxins as well. It takes about 2 weeks after a vaccination for the immune system to produce a sufficient number of antibodies for immunity. If you should be exposed to what you were just vaccinated against, you'll probably get the disease/infection. Although most vaccines work this way, there are a few exceptions, such as with the hepatitis B series, a 3-dosage vaccine given over 6 months, all three doses must be given for immunity.

    "Do they inject the dead virus itself?" -- Viruses are not alive to begin with so they can't be dead, either. Viruses are either active or inactive. In the injectable vaccine, particles, pieces of inactivated virus are used but the important part is the antigen on the particles. In the intranasal form of the vaccine, an active virus is use but it's been attenuated, which means modified, altered. The way it's been altered is that it's been weakened so that the virus has limited replication ability. Neither form, inactivated or active attenuated, can cause infection. But your immune system will think it's under attack. It's doesn't know the difference between a vaccine and the real thing. But because vaccines aren't the actual disease/infection, the immune response is short-lived as the antigens in the vaccine are soon dispensed with.

    Source(s): I'm a nurse.
  • 7 years ago

    Vaccines are weakened strands of the virus that creates an immunity when injected and your body fights off the weak version preventing you from getting the actual virus. Like once you get the chicken pox you can't get it again because your body is immune now kind of thing, except you don't actually have to get sick because the strand is too weak. Hope This Helps :)

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