Is Pfizer Vaccine Effective Against Brazil Variant?

Pfizer Coronavirus Vaccine
Source: AP
  • Studies suggest that the Brazil coronavirus variant is twice as transmissible as the original virus.
  • Scientists tested blood samples of vaccinated individuals against an engineered version of the Brazil variant.
  • The laboratory study showed the Pfizer vaccine as effective against the Brazilian variant.

Since the beginning of the pandemic, Brazilian president Jair Bolsonaro has not only downplayed the situation in the country but also opposed strict quarantine measures. Thus, leading Brazil to record more than 11 million cases and 270,000 deaths. Experts believe such measures, coupled with a lack of vaccines, has led to the emergence of coronavirus variants across the country. Most dangerous of which is the variant P1. According to studies, this particular Brazil variant is up to 2 times more transmissible than the previous strain. It can also evade the immune response and increase the chance of reinfection by 25% to 60%. Moreover, this highly contagious strain has now spread across the world, including the US.

Scientists from Pfizer, BioNTech, and the University of Texas Medical Branch investigated their vaccine’s efficacy against the Brazil variant, P1. They published their findings in the New England Journal of Medicine.

Pfizer Vaccine Neutralizes Brazil Coronavirus Variant

First, researchers engineered a virus in the lab, containing the spike protein mutation present in the Brazil variant, P1. Spike protein allows a virus to bind more tightly to human cells. Therefore, vaccines tend to target the spike protein of the virus.

Next, researchers obtained serum samples from 15 vaccinated individuals who had received their second dose 2 to 4 weeks ago. They tested the samples against the engineered version of the P1 variant. As a result, the antibodies present in the blood effectively neutralized the virus. Moreover, the neutralizing ability was equal to that of the original coronavirus.

However, these results are yet to be confirmed through a real-world study.

Previously, the Pfizer vaccine has also shown promise against the UK and South African variant of coronavirus, although the South African variant may reduce antibodies produced by the vaccine. However, Pfizer believes its vaccine provides a good level of protection against the variant. The vaccine manufacturer is currently planning to test a third booster dose to increase its efficacy against the variant.


Liu, Yang, et al. “Neutralizing Activity of BNT162b2-Elicited Serum.” New England Journal of Medicine, 2021, doi:10.1056/nejmc2102017.

Faria, Nuno R., et al. “Genomics and Epidemiology of a Novel SARS-CoV-2 Lineage in Manaus, Brazil.” 2021, doi:10.1101/2021.02.26.21252554.


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