Delay Pfizer COVID-19 Vaccine's 2nd Inoculation To Boost Supply? Here's What Research Is Saying

The first dose of Pfizer Inc PFE and BioNTech SE BNTX vaccine could be highly efficacious against COVID-19, a study has found — fueling debate over delaying the second dose to stretch supplies, Reuters reported Thursday.

What Happened: The first dose of the Pfizer vaccine could be 85% effective, according to a study of healthcare workers at Israel’s Sheba Medical Center, Reuters noted.

Research in Canada — based on documents submitted by Pfizer to the United States Food and Drug Administration found that the first dose provides 92.6% efficacy, Reuters reported separately.

The Canadian researchers suggested that the second dose be delayed to maximize the vaccine’s distribution.

The Israeli medical facility said there was an 85% reduction in symptomatic COVID-19 among the 7,214 staff members that received their first shot in January. The overall reduction in infections, which includes asymptomatic cases was 75%.

Why It Matters: The Sheba study was conducted on a “mostly young and healthy” cohort, as per Sheba epidemiologist Gili Regev-Yochay.

British authorities have lengthened the gap between the first and second doses of the Pfizer vaccine to 12 weeks. 

Sheba found a 95% efficacy for the Pfizer vaccine in a two-dose regimen given 21 days apart, as per Reuters.

Pfizer said that alternative dosing schedules have not been evaluated and the decisions are at the discretion of the health authorities. 

Price Action: Pfizer shares closed 0.95% lower at $34.56 on Thursday. On the same day, BioNTech shares closed 0.8% lower at $112.65 and fell 0.58% in the after-hours session. 

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