S Africa variant could reduce Covid vax protection: Pfizer-BioNTech

The South African variant of Covid-19 may significantly reduce antibody protection from the Pfizer-BioNTech vaccine, as per a laboratory study, the pharmaceutical companies said. However, human trials are still to be conducted in this regard.

According to the study, published in The New England Journal of Medicine, although the results indicated a reduction in neutralisation of virus with all the South African variant spike glycoprotein mutations, the vaccine was still able to neutralise the virus.

This finding is consistent with recent reports of the neutralisation of variant SARS-CoV-2 or corresponding pseudoviruses by convalescent or post-immunisation sera, the companies said in a statement on Wednesday.

Pfizer and the University of Texas Medical Branch (UTMB) investigated the full set of South African variant (also known as B.1.351 lineage) spike mutations.

To this aim, three genetically engineered recombinant viruses were produced. One virus had the full set of spike glycoprotein mutations found in the South African variant and the other two had subsets of these mutations.

The viruses were tested against a panel of sera from 15 participants in the previously reported Phase 3 trial who had been immunised with the Pfizer-BioNTech Covid-19 vaccine.

Pfizer-BioNTech said they are taking the necessary steps, making the right investments, and engaging in the appropriate conversations with regulators to be in a position to develop and seek authorisation for an updated mRNA vaccine or booster once a strain that significantly reduces the protection from the vaccine is identified, the company said.

Pfizer-BioNTech are currently evaluating neutralisation of SARS-CoV-2 with the Brazilian strain spike mutations, as well as mutations from other emerging SARS-CoV-2 variants, and they continue to conduct studies to monitor the vaccine’s real-world effectiveness.

The pharmaceutical companies believe that the flexibility of BioNTech’s proprietary mRNA vaccine platform is well suited to develop new vaccine variants, if required.