Real-World Evidence Confirms Pfizer COVID-19 Vaccine Effectiveness

March 22, 2021 - The Israel Ministry of Health (MoH), Pfizer, and BioNTech recently shared real-world evidence showing that the Pfizer-BioNTech COVID-19 vaccine, BNT162b2, elicited lower incidence rates of coronavirus in individuals who were fully vaccinated. 

Specifically, researchers found that vaccine effectiveness was at least 97 percent in preventing symptomatic disease, severe or critical disease, and death. Additionally, the analysis found vaccine effectiveness of 94 percent against asymptomatic SARS-CoV-2 infections. 

For all outcomes, effectiveness was measured from two weeks after the second dose.

The new data confirms previously released data from MoH, which showed that BNT162b2 was effective against virus cases, severe and critical hospitalizations, and death. 

Additionally, the data confirms findings from the company’s Phase 3 trial at the end of November, which showed that BNT162b2 elicited a vaccine efficacy rate of 95 percent efficacy in participants without prior SARS-CoV-2 infection, as well as with and without prior SARS-CoV-2 infection. 

“We are extremely encouraged that the real-world effectiveness data coming from Israel are confirming the high efficacy demonstrated in our Phase 3 clinical trial and showing the significant impact of the vaccine in preventing severe disease and deaths due to COVID-19,” Luis Jodar, PhD, senior vice president & chief medical officer of Pfizer Vaccines, said in the announcement. 

“Altogether, these data are critical to understanding the role of vaccination in combating the pandemic and provide hope to other countries dealing with this devastating disease, which has now afflicted the world for more than a year,” Jodar continued.

Findings from the analysis were derived from de-identified aggregate Israel MoH surveillance data collected between January 17 and March 6, 2021, a Pfizer spokesperson said. At the time, BNT162b2 was the only vaccine available in the US when B.1.1.7 was the dominant strain. 

Following FDA’s emergency use authorization for BNT162b2 in Israel at the beginning of December, MoH launched a national vaccination program targeting individuals 16 years of age and older.

The program represented a total of 6.4 million people, or 71 percent of the population. 

“Israel’s strong health system and an unprecedented societal mobilization and awareness allowed us to achieve high national uptake of the COVID-19 vaccine in a short period of time,” Yeheskel Levy, Israel MoH director, said in the recent announcement. 

“Incidence rates in the fully vaccinated population have massively dropped compared to the unvaccinated population, showing a marked decline in hospitalized cases due to COVID-19. We aim to achieve even higher uptake in people of all ages, which gives us hope of regaining normal economic and social function in the not so distant future,” Levy continued. 

B.1.1.7 lineage is a rapidly spreading variant of SARS-CoV-2 first detected in the UK that carries a larger than usual number of genetic changes. Specifically, there are 10 mutations on the spike protein.

The two earliest sampled genomes that belong to the B.1.1.7 lineage were collected in September in Kent, England and another from Greater London, a recent study found. 

At the end of January, Pfizer and BioNTech announced that their vaccine elicited antibodies that neutralize B.1.1.7 lineage.

The in-vitro study investigated the capability of sera from individuals immunized with the vaccine to work against new mutant strains of the coronavirus. Researchers found that in sera of participants from a German Phase 1/2 strain, neutralizing range was biologically equivalent to the Wuhan SARS-CoV-2 spike. 

The neutralization of the pseudovirus bearing the UK strain spike by BNT162b2 means that COVID-19 caused by the UK virus variant can also be prevented by immunization with BNT162b2, Pfizer explained in the January announcement. 

This is promising, as a UK study claimed that B.1.1.7 lineage is 56 percent more contagious than the strain found in the states. The variant may also be up to 70 percent more transmissible.