>There's an Israeli study showing that the Pfizer vaccine gives some protection after 1 dose but most of its benefit after the 2nd dose. This includes the UK variant, fwiw. The second dose was given at 3 weeks in this study compared to longer delays elsewhere.
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>Fauci was worried that delay may select for stronger strains that need the second dose for optimum effectiveness.
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>Not all the vaccines need 2 doses, fwiw. E.g. the Johnson and Johnson effort needs only one dose, or so they say today.

Yup, I've tried to read as much as I can on the Israeli study.....and yes, Fauci did state that for the vaccines that come in two, it's very important to get the 2nd one.