NEJM | Pfizer Vaccine Shows Neutralizing Effect Against Three Major New Coronary Mutant Viruses

▎The content team editor of WuXi AppTec recently, researchers from Pfizer and BioNTech, in collaboration with researchers from the University of Texas Medical Branch, published an article in the New England Journal of Medicine (NEJM), evaluating The sera of individuals vaccinated with the new crown vaccine BNT162b2 are directed against the neutralizing ability of the three new coronavirus mutations originally found in the United Kingdom, South Africa, and Brazil.

The results of in vitro studies showed that the neutralizing ability of serum against the B.
1.
1.
7 virus strain originally found in the UK and the P1 virus strain found in Brazil did not decrease.
For the B.
1.
351 virus strain originally found in South Africa, the neutralizing ability did not decrease.
However, it still remains at a relatively high level.

In this study, the researchers introduced genetic mutations carrying the spike protein of the B.
1.
1.
7, B.
1.
351, and P1 virus strains into a wild-type virus strain isolated in January 2020 to generate Three types of recombinant new coronaviruses were released.

Researchers also generated two other virus strains carrying partial B.
1.
351 gene mutations.

Then, the researchers tested the neutralizing ability of 20 serum samples obtained from 15 volunteers who participated in the pivotal clinical trial of BNT162b2.

These serum samples were obtained 2 or 4 weeks after the participants received the second dose of vaccine.

Experimental results show that all serum samples can effectively neutralize wild-type new coronaviruses and virus strains containing mutations of different new coronaviruses.

The geometric mean neutralization titer (PRNT50) for wild-type new coronavirus is 532, the value for the strain carrying the B.
1.
1.
7 spike protein is 663, the value for the P1 virus strain is 437, and the value for the B.
1.
351 virus strain is The value is 194. ▲The neutralization ability of the serum of inoculated BNT162b2 volunteers against different new coronavirus mutant strains (picture source: reference [1]) In two recombinant virus strains carrying partial mutations in the spike protein of the B.
1.
351 virus strain, they carry the N-terminus The neutralization titer of the virus strain with 242-244 deletion mutation was 485, while the neutralization titer of the virus strain with K417N, E484K, and N501Y gene mutations in the receptor binding domain was 331.

These data show that the K417N, E484K, and N501Y variants in the receptor binding domain have a greater impact on antibody neutralization than the 242-244 deletion variants in the N-terminal domain.

The researchers said that overall, the neutralizing effect of the immune serum on B.
1.
17 and P1 is about the same as that of the wild type.

The neutralizing ability of B.
1.
351 has been weakened, but it still remains at a relatively high level.

The neutralizing antibody titer against B.
1.
351 is still greater than the neutralizing antibody titer achieved after a dose of BNT162b2 vaccine.

The results of clinical trials show that the efficacy of preventing COVID-19 can be observed after a dose of BNT162b2.

However, the researchers also pointed out that the protective efficacy calculated from the neutralizing antibody and T cell response still needs to be verified by evidence collected in the real world.

Pfizer and BioNTech have already carried out clinical studies to evaluate the protective effect of an enhanced vaccination against the new coronavirus 6-12 months after the inoculation of two doses of BNT162b2.

The two companies are also in discussions with regulatory agencies to quickly test new vaccines against B.
1.
351 or other mutant strains with immune escape characteristics.

Note: This article is intended to introduce medical and health research, not a treatment plan recommendation.

If you need guidance on treatment plans, please go to a regular hospital for treatment.

Reference: [1] Liu et al, (2021).
Neutralizing Activity of BNT162b2-Elicited Serum.
NEJM, DOI: 10.
1056/NEJMc2102017.