If you can get Covid twice, how will a vaccine work?
 

I am not anti vax.

There are reports of people getting COVID-19 more than once. From another thread, Fast Fred knows a guy...

If we can get this virus more than 1 time, how will a vaccine work?

Isn’t the mechanism of a vaccine that your body developed an immune response to the dead cells of a virus within the vaccine? This immune response then knows how to fight off live cells of the virus. If your body has successfully fought off Covid once, shouldn’t your immune response prevent you from getting it again?

I’m not arguing if the vaccines work, I want to understand HOW they will work on a virus that you can get twice...

It's a numbers game ... though not a game at all. Almost nothing is 100% ... and just like the flu, maybe the second time is a slightly different "strain"? I have no expertise whatsoever ...

You need to understand how antibodies work.

Antibodies do not stop you from "getting" the virus. It gives your body the ability to quickly fight it off. More antibodies = bigger response. The Moderna vaccine produces 2-4 times the antibodies of a natural infection.

So in realty, anyone who is exposed, gets the virus. But you may not develop the disease or only develop a mild case if you are exposed if you have anti-bodies.

Someone who had a mild case might not have developed a full load of antibodies.

Antibodies also may not "stick around". We may need yearly boosters. This is one of the things being tracked in my vaccine study. 6 months after my second injection they are going to take more blood for the anti-body study.

In fact, the Moderna vaccine works like a booster system. One shot to "prime" you, then a second to get your body to really produce massive antibodies. Which means we may need to a yearly booster probably of a lower level than the initial shots.

Viruses mutate. No one knows how fast Covid-19 mutates, but it could have changed enough not to be recognized by the immune system.

The seasonal flus mutate, that's why you have to get vaccinated every year. The vaccine is different for them every year to try to keep up with the mutations.

The seasonal flu is a recombination of various types of flu. The COVID vaccines are developed to recognize the spike proteins common to these types of virus.

The "common cold" is a Coronavirus. These people may have cured the "common cold".

The mutation rate of the SARS2 virus is being tracked closely, actually. It seems to mutate slowly, and so far not meaningfully. In particular the part of the virus that the vaccines target does not seem to mutate much.

We live in a world free from small pox. Only because of vaccines. Same for the most part for polio and several other deadly diseases.

I received the small pox vaccine twice. The second time it did not "take" so I was still immune.

I will take the vaccine when it becomes available for me.

I have never had a flu shot, nor the flu since I was a kid. Because of my parents, I will get one of these when available.

Um...smallpox still exists, it still breaks out, and it can still run rampant across the planet because almost everyone my age and younger had no vaccine. In 20 years, people who are vaccinated for smallpox in the US will be pretty rare.

The vaccine was only one part of ending the smallpox plague in the 70s. Coordinated effort from governmental agencies across the planet (WHO, CDC, etc), and the African use of containment (shut down and seal the borders of a community infected, and let it burn through the people) went a long way towards stopping a worldwide pandemic.

As far as I know the last naturally occurring case of small pox happened in 1977.

I could be wrong, I though there were small outbreaks in the recent past (10 years).

Last I heard Small Pox was declared eradicated. Polio is being aggressively vaccinated against in the areas where it is still active.

As a kid I had the mumps and that is mostly stopped because of vaccinations. Mumps is a disease no adult male ever wants. The testicles can swell to the size of grapefruits or even bigger.

My dad was an Air Force pilot and traveled all over the world. He filled up two vaccination record books.

yes, slow in relative terms - this virus family has the "ability" to test for and repair errors in the genetic code (RNA for these)

same general idea as a checksum

Small pox has been eradicated.

https://www.cdc.gov/smallpox/index.html#:~:text=Thanks%20to%20the%20success%20o f,occurring%20smallpox%20have%20happened%20since.

There are two stocks of small pox kept in secure ultra cold storage facilities - one in the US and one in Russia (supposedly secure). They are kept in case they are needed for research in case...

... in case a related virus evolves into smallpox again, or something very close to it

or in case we missed something, some natural reservoir of smallpox

and BTW as the arctic warms up, scientists are finding new bacteria that were previously deep frozen

- so stay tuned

It is my understanding where they have found re-infection, it has been the same strain, which is concerning. Also of note is that as opposed to most viral infections, those that get it twice seem to be much sicker the second round.

So to answer the OP, the vaccine is not a magic silver bullet. I had to get the small pox vaccine as a young kid and I don't remember much about it, but I have the scar to prove it. In 1971 we were living in Hawaii and the USAF required our family to get a small pox vaccination to return to the mainland. I kept asking why, as there were no small pox in Hawaii or in the mainland, and of course with the military, it came down to "those are the rules" so I was vaccinated a second time. So even small pox vaccine is not a lifetime cure. We all may have to get a second shot in several months to keep us safe from the Kung Flu.

I remember mine. They covered it with a clear plastic bubble. It scabbed over after a while.

About all I remember was picking at the scab and mom telling me not to.

Regarding short-term Covid "reinfection", I haven't found anything yet that wasn't purely anecdotal, or 100% confirmed with false positive/negative tests completely ruled out, or not involving those with already-compromised immune systems.

With the (genetically stable) characteristics of this virus, an infection via one strain should provide both antibody and cellular immunity for other strains.

As such, a single vaccine will be effective against many strains of Covid, so an ever-changing "cocktail" will not be needed...for now.

I got the small pox in 15'....