Pfizer-BioNTech COVID-19 Vaccine Significantly Prevents Infection, Severe Disease in Israel

May 5, 2021

Kevin Kunzmann is the managing editor for Contagion, as well as its sister publication HCPLive. Prior to joining parent company MJH Life Sciences in 2017, he worked as a health care and government reporter for The Pocono Record, and as a freelance writer for NJ Advance Media, The Express-Times, The Daily Journal, and more. He graduated from Rowan University with a degree in journalism in 2015. In his spare time, he enjoys reading, cooking, running his dog, and complaining about the Mets. Follow him on Twitter @NotADoctorKevin or email him at [email protected]

New real-world research suggest the vaccine may help provide control of the pandemic virus.

Two-dose administration of Pfizer-BioNTech COVID-19 vaccine BNT162b2 is associated with greater than 90% prevention of asymptomatic, symptomatic and severe COVID-19 infection, according to new real-world findings out of Israel.

The three-month study outcomes from the nation with the greatest rate of vaccinated adults showed persons aged ≥16 years old given the two-dose mRNA vaccine have similarly benefitted in substantial risk reduction from hospitalization (97.5%) and death (96.7%) related to the pandemic virus.

Investigators, led by Dr. Sharon Alroy-Preis, of the Israel Ministry of Health published in The Lancet Wednesday evening, believe these newest real-world outcomes provide evidence of future control over COVID-19 among a more vaccinated global population.

“Until this point, no country in the world had described the national public health impact of a nationwide COVID-19 vaccination campaign,” Alroy-Preis said in a statement. “These insights are hugely important because, while there are still some considerable challenges to overcome, they offer real hope that COVID-19 vaccination will eventually enable us to control the pandemic.”

The new study was borne out of Israel’s Ministry of Health campaign to immunize the approximate 6.5 million residents aged ≥16 years old following the emergency authorization of BNT162b2 for such eligible individuals.

Alroy-Preis and colleagues conducted a real-world efficacy estimation study of two-dose vaccine against SARS-CoV-2 infection and outcomes, with added consideration to nationwide public health impact of the vaccine’s introduction to the Israel population.

Their study used national surveillance data from January 24 – April 3 of this year to define the total cases of laboratory-confirmed SARS-CoV-2 infections and disease-related outcomes, including asymptomatic and symptomatic infection, COVID-19 hospitalization, severe or critical hospitalization, and death.

Vaccine efficacy against such outcomes were calculated by comparison of their occurrence in fully-vaccinated persons (≥7 days after their second dose) versus non-vaccinated persons.

Decade-length age groups, sex, and calendar weeks were used to adjust the binomial regression model for vaccine efficacy assessment.

Additionally, the investigators estimated the prevalence of the then-spreading B.1.1.7 variant in Israel through the proportion of spike gene target failures on PCR tests among the nationwide sample of SARS-CoV-2 positive specimens.

In total, the team observed 232,268 SARS-CoV-2 infections, 7694 COVID-19 hospitalizations, 4481 severe or critical hospitalizations, and 1113 COVID-19 deaths among people aged ≥16 in the observed time period.

Israel’s eligible population was 72.1% fully vaccinated with 2 doses of BNT162b2 by April 3.

Vaccine effectiveness at ≥7 days following the second dose, adjusted for demographics, were as follows for the selected outcomes:

95.3% against SARS-CoV-2 infection (95% CI, 94.9 – 95.7)
91.5% against asymptomatic SARS-CoV-2 infection (95% CI, 90.7 – 92.2)
97.0% against symptomatic COVID-19 (95% CI, 96.7 – 97.2)
97.2% against COVID-19 related hospitalization (95% CI, 96.8 – 97.5)
97.5% against severe or critical hospitalization (95% CI, 97.1 – 97.8)
96.7% against COVID-19 related death (95% CI, 96.0 – 97.3)

Investigators additionally observed that across all age groups, SARS-CoV-2 outcome incidence declined with increasing vaccine coverage—meaning a more vaccinated population was associated with decreased SARS-CoV-2 infection and COVID-19 illness and death.

The B.1.1.7 variant, understood to be more transmissible than the most prevalent strain of SARS-CoV-2, was prevalent in 94.5% of all observed infection samples from that time period.

Alroy-Preis and colleagues concluded the two-dose BNT162b2 COVID-19 vaccine is “highly effective” across all groups in preventing all observed virus outcomes, included those causes by the B.1.1.7 variant.

“Finally, the high effectiveness against all SARS-CoV-2 infections and apparent effectiveness against infections that were asymptomatic at the time of epidemiological investigation suggest that BNT162b2 might reduce SARS-CoV-2 transmission,” investigators wrote. “Taken together, these findings suggest that high vaccine uptake can meaningfully stem the pandemic and offers hope for eventual control of the SARS-CoV-2 outbreak as vaccination programmes ramp up across the rest of the world.”