Thread by @petermbenglish

Hi @DocStrain - were you involved in this paper?

medrxiv.org/content/10.110…

I'm struggling to understand the first sentence of the abstract: "Delayed second-dose SARS-CoV-2 vaccination trades maximal effectiveness for a lower level of immunity across more of the population."
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Longer prime-boost intervals generally elicit better immunity. So "delaying the second dose…" is likely to ensure a higher level of immunity across the population (once the booster dose has been given).
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Also "…patients receiving these drugs should be prioritized for optimally timed second doses."

What is the "optimal" timing for a second dose?
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It takes time for the immune system to respond to the first dose. In general, extending the prime-boost interval leads to a greater eventual response.

This paper suggests that patients on TNF blockers may not respond as well to a single dose, so…
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…so delaying the second dose may leave them at risk for longer.

Perhaps the answer may be…
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…Perhaps the answer may be that the optimum regime for such patients would be to give an additional, early booster dose, followed by a third dose (a second booster dose) when their immune systems have had more time to respond to the first doses.
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