How effective a COVID-19 vaccine do we need?

In medicine, as in life, nothing is perfect.

This is true of vaccines. No vaccine is 100% effective. Yet, vaccines have produced massive declines in many serious illnesses, and succeeded in eradicating two such illnesses (smallpox in humans and rinderpest in cattle).

Herd immunity

Since COVID-19 has come along, everyone is talking about herd immunity. This is a straightforward idea. Let’s say I’ve never had smallpox. I’ve never been vaccinated against it. But, if you put me in a group of people who are immune to smallpox, I’ll never catch smallpox. Why? Because they can’t catch it to spread it to me.

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An interesting approach to COVID-19

This is an interesting article on a possible approach to long-standing COVID-19 immunity here.

One of the problems with other approaches is that other coronavirus immunity is not typically long-lasting, and fades. Thus, even herd immunity may not give us long-term protection, and standard vaccine approaches might need to be repeated frequently.

This approach, if feasible, would be a game changer. And its written by someone who actually knows what they’re talking about.

Real world data on COVID-19 antibody tests – we ain’t there yet

We’ve talked here about the problems and limitations of antibody tests. We’ve seen others discuss it. And a primer on the mathematical whys and wherefores is available here.

Today some pre-publication data on a variety of US antibody tests were released, and they aren’t great–and they illustrate precisely the problems discussed above:

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