Pfizer/BioNTech’s COVID-19 vaccine neutralises Brazil variant, suggests study

Pfizer/BioNTech’s COVID-19 vaccine has been found to neutralise the variant discovered in Brazil, according to a laboratory study published in the New England Journal of Medicine.

The study, conducted by scientists from Pfizer and BioNTech alongside researchers from the University of Texas Medical Branch, used blood samples from people who had received the BNT162b2 vaccine.

They then used an engineered version of the virus that carries the same mutations on the spike protein of the P.1 variant, which is currently rapidly spreading in Brazil, to determine the level of neutralisation produced by the Pfizer/BioNTech vaccine.

The results suggested that the vaccine was able to neutralise the P.1 variant, with the levels of neutralisation ‘roughly equivalent’ to the jab’s effect on the original SARS-CoV-2 strain.

Previously, the Pfizer/BioNTech vaccine has been found to neutralise variants discovered in the UK and South Africa.

However, neutralisation of the South Africa variant, or B.1.351-spike virus, was reduced by around two-thirds in BNT162b2-vaccinated blood samples.

The researchers noted that it is difficult to determine the effect this reduction in antibodies will have on the vaccine’s efficacy against the B.1.351 variant.

This is because there is currently no way to determine the level of antibodies required to protect against the virus.

“Ultimately, conclusions about vaccine-mediated protection that are extrapolated from neutralisation or T-cell data must be validated by real-world evidence collected in regions where the SARS-CoV-2 variants are circulating,” commented the researchers.

Pfizer/BioNTech recently initiated a study to evaluate the safety and immunogenicity of a third dose of their COVID-19 vaccine.

The aim of this study is to understand the effect of a booster dose on immunity against COVID-19 caused by the circulating and potential newly emerging variants.

The companies are also in ongoing discussions with regulatory authorities regarding a clinical study to evaluate a variant-specific vaccine that would have a modified mRNA sequence.

This study would use a new construction of the Pfizer/BioNTech vaccine based on the B.1.351 variant, according to the companies.

Another vaccine maker – Moderna – is also developing a variant-specific vaccine candidate, mRNA-1273.351, against the B.1.351 variant discovered in South Africa.

The company is also developing a multivalent booster candidate, mRNA-1273.211, that will combine Moderna’s authorised vaccine with the mRNA-1273.351 candidate in a single vaccine.

Last week, the UK’s Medicines and Healthcare products Regulatory Agency (MHRA) announced that it will fast-track approvals for COVID-19 vaccines that have been modified to address new variants.

The new guidance from the ACCESS Consortium – a coalition of regulatory authorities from the UK, Australia, Canada, Singapore and Switzerland – said that ‘lengthy’ clinical studies that do not add to the regulatory understanding of a vaccine’s safety, quality or effectiveness would not be required for approval.

“Our priority is to get effective vaccines to the public in as short a time as possible, without compromising on safety. Should any modifications to authorised COVID-19 vaccines be necessary, this regulatory approach should help to do just that,” said Christian Schneider, chief scientific officer of the MHRA.