Vaccines: mix them.
We have to realize that the only reason why we mandate 2 doses of some vaccines is because that's what we tested and it turned out to work.
It doesn't mean 2 doses is ideal.
It doesn't mean that amount is ideal.
It doesn't mean 3 weeks apart is ideal.
We have to realize that the only reason why we mandate 2 doses of some vaccines is because that's what we tested and it turned out to work.
It doesn't mean 2 doses is ideal.
It doesn't mean that amount is ideal.
It doesn't mean 3 weeks apart is ideal.
The question then is: what is ideal?
We can't test all combinations w/ RCT (randomized controlled trial). It's hard enough to just test vaccines.
We can rely on priors and new evidence.
We can't test all combinations w/ RCT (randomized controlled trial). It's hard enough to just test vaccines.
We can rely on priors and new evidence.
Priors: the world is messy. The variants present during a RCT are not all the variants ppl will face. Things evolve.
Which combination do you think will be more effective: one that prepares you twice to the exact same enemy, or one that shows you different enemies?
Which combination do you think will be more effective: one that prepares you twice to the exact same enemy, or one that shows you different enemies?
The more diverse your enemy, the more your body can learn to fight a generic enemy rather than a specific one.
So the prior should be that mixing vaccines is better than facing twice the same.
So the prior should be that mixing vaccines is better than facing twice the same.
This intuitive prior was already tested in the past:
pubmed.ncbi.nlm.nih.gov/26691569/
pubmed.ncbi.nlm.nih.gov/26691569/
And the evidence on COVID is mounting, from more
protective antibodies
medrxiv.org/content/10.110…
nature.com/articles/d4158…
protective antibodies
medrxiv.org/content/10.110…
nature.com/articles/d4158…
As for the risks, it doesn't appear to lead to more hospitalizations or deaths. It does make people feel worse, which is an indication that the immune system is working overtime.
So it's exactly what our priors would tell us to expect.
thelancet.com/journals/lance…
So it's exactly what our priors would tell us to expect.
thelancet.com/journals/lance…
And logistically it's so much easier to mix-and-match than to have to give the exact same type of vaccine to every person.
Some companies suggest we need a 3rd boost to prep for Delta. In fact, it would be a substantially better idea to mix as many safe and effective vaccines as possible.
For all these reasons, many countries already allow it: CA ES FR UK IT SE DE SK
nytimes.com/2021/06/24/wor…
nytimes.com/2021/06/24/wor…
The US is late to the game again because it's being overly cautious.
But the evidence now favors mix-and-match. It's time for countries to default to it, and only revert if new evidence appears to contradict it.
But the evidence now favors mix-and-match. It's time for countries to default to it, and only revert if new evidence appears to contradict it.
If you're interested, search for "heterologous prime-boost".
More in my article this week
unchartedterritories.tomaspueyo.com
More in my article this week
unchartedterritories.tomaspueyo.com
BTW, is there a better expression for this mental pitfall than "Better the devil you know than the devil you don't"?
In this case a booster of the same vaccine is not a devil. It's good. But it's likely worse than the alternative.
So what's a good name for this?
In this case a booster of the same vaccine is not a devil. It's good. But it's likely worse than the alternative.
So what's a good name for this?
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