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Covid-19: Pfizer BioNTech vaccine reduced cases by 94% in Israel, shows peer reviewed study

BMJ 2021; 372 doi: (Published 25 February 2021) Cite this as: BMJ 2021;372:n567

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Who really needs a Covid-19 vaccine?

Dear Editor,
So far Pfizer BioNTech’s vaccine has been 94% effective in reducing Covid-19 cases during Israel’s mass vaccination campaign. (Wise, BMJ 2021;372:n567, Feb 25) This refers to relative population benefit, but many people want to know about individual benefit, which can be expressed as absolute risk reduction (ARR). The following table provides these numbers, based on Figure 2 in the original article by Dagan et al, NEJM 2021, online Feb 24, DOI:10.1056/NEJMoa2101765. There were 596,618 subjects in each group.
PCR+ Symptomatic Hospitalized Severe illness Death
Unvaccinated 6100 3607 259 174 32
Vaccinated 4460 2389 110 55 9
ARR 0.0027 0.002 0.00025 0.0002 0.000039
NNTV 370 500 4000 5000 25,641
NNTV is the Number Need To Vaccinate, and = 1/ARR. For example, 5000 individuals must be vaccinated to prevent one severe illness from Covid-19. The other 4999 individuals derive no benefit but are subject to adverse vaccine effects, which are yet to be quantified. Numbers will change as time goes on and new data are acquired.
Public health authorities in the US continue to push for universal vaccination and continued lockdowns, even as cases rapidly decline. However, some experts believe we need to open things up (Makary, “We’ll Have Herd Immunity by April”, Wall Street Journal, 19 February 2020) Some of us believe that vaccination should be targeted at the ~20% of the population that is truly high risk, and let the rest of the population acquire broader and more lasting protection from natural infection, an approach that may be safer and more cost-effective overall. (
ALLAN S. CUNNINGHAM 28 February 2021

Competing interests: No competing interests

28 February 2021
Allan S. Cunningham
Retired pediatrician
Cooperstown NY USA <