
Ask HN: Why is developing a vaccine for the covid19 so hard? - ahmedfromtunis
To the best of my knowledge, vaccines are made out of &#x27;dead&#x27; viruses to &#x27;train&#x27; the body&#x27;s immune system to fight the real deal when the time comes.<p>If so, why is coming up with a vaccine for the covid19 is hard? I read that this is due to the lack of understanding of the virus, but would it matter if all we have to do is to make a soup out its dead corpse?
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sushshshsh
The process of developing, testing and licensing a vaccine for widespread
population use is designed to be slow, deliberative, peer-reviewed,
reflective, evidence-based, so that we don't make mistakes," Poland said.

Going too fast could lead to a vaccine that's not effective or, worse, can
cause serious health problems, Poland said.

Seems like the answer is bureaucracy and also an abundance of caution

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croes
[https://www.latimes.com/science/story/2020-03-12/why-does-
it...](https://www.latimes.com/science/story/2020-03-12/why-does-it-take-so-
long-to-make-a-coronavirus-vaccine)

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ahmedfromtunis
Thank you! Should I be ashamed to say this is the first time I find out there
are vaccines for bacteria?

While the article is rich with information, it just glossed over the main
issue: "One classic technique involves injecting a person with a killed virus.
Another uses live viruses that have been grown and deliberately weakened,
typically by removing specific genes in their RNA or DNA. Both of these
strategies take some time, and scientists worry that if they use them on novel
viruses, they may not behave the way researchers predict."

But what is exactly taking time? Killing the virus and/or making a weak
version of it? And in what way they can behave unpredictably? Alas, so many
questions left unanswered :(

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Gibbon1
One thing that in the past has taken a lot of time is proving the vaccine
works 'in the wild'. Which means you vaccinate thousands of people and then
wait a couple of years and see if they get infected or not. If they do, and
that happens, your vaccine is bunk. Sometimes vaccines only provide short term
immunity. Fading immunity is a problem with some vaccines.

And you also monitor them to see if there are adverse effects. Too many
adverse effects and you're vaccine isn't safe enough. Adverse effects are like
anaphylactic shock, guillain barre syndrome. And that sometimes candidate
vaccines both fail to provide protection but make the infection worse.

There is a balancing act between how bad a disease and the risk you're willing
to take with the vaccine. Covid19 is probably the worst. It's really dangerous
to certain population groups like the elderly and people with certain health
issues. And much less so to young healthy people. To get rid of covid19 we're
going to have to vaccinate 90% of the world population which means the vaccine
needs to be 100% safe.

Anyway you should not be ashamed just because you don't know something.

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ahmedfromtunis
Thank you for your kind words and for this awesome explanation that did
finally quench my thirst for knowledge on the matter! Much appreciated!

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Gibbon1
It's fascinating. A lot of fields have a short list of theoretical foundations
that everything builds on. Immunology is the reverse. An applied science with
lot of important ad hoc observational things that are important yet poorly
understood.

