Prognosis
Delayed Second Dose Turns Into a Win for Vaccine-Starved Places
- More time between shot boosts efficacy, delays full immunity
- Singapore leads Asia with focus on one shot for all in August
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Faced with a limited supply of shots and anxious populations waiting their turn, more countries are turning to an initially controversial strategy that’s now been vindicated by scientific studies: doubling or tripling the intervals between the first and second Covid vaccine dose.
A delay in getting the second shot not only allows the existing supply of shots to be more widely distributed, it boosts their protective power by giving the immune system more time to respond to the first inoculation. Levels of antibodies produced to fight off the virus are 20% to 300% higher when the follow-up vaccine comes later, new research shows.