Canadian researchers assert that a single shot of the Covid vaccine is as effective as two and that the second shot only hikes effectiveness marginally.
According to the FDA, a single dose of Pfizer vaccine is 92.6 percent effective after two weeks while a single Moderna vaccine dose is 92.1 percent effective following the same period.
When the second shot of Pfizer’s vaccine is administered, the effectiveness climbs to 94 percent.
The findings urge health officials to give the second doses of Covid vaccines to those who did not get one at all “given the current vaccine shortage.”
“With such a highly protective first dose, the benefits derived from a scarce supply of vaccine could be maximized by deferring second doses until all priority group members are offered at least one dose,” they suggested.
“There may be uncertainty about the duration of protection with a single dose. But the administration of a second dose within one month after the first, as recommended, provides little added benefit in the short term, while high-risk persons who could have received the first dose with that vaccine supply are left completely unprotected.”
