Pfizer vaccine effective against infectious Covid-19 variant, Moderna shot also offers protection: Reports
The coronavirus vaccine developed by Pfizer and BioNTech is effective against the new, more infectious coronavirus strain that was first identified in Britain, reveals analysis. The in vitro study was conducted with samples taken from people aged 18 to 85 who had been vaccinated.
When vaccinated with a dose of Pfizer vaccine, the UK coronavirus strain is neutralized, or rendered inactive by the medicine. The research team emphasizes that they found “no biologically significant difference in neutralization activity.”
The scientists created a pseudovirus with the UK Covid-19 strain’s same mutations to test against the Pfizer-BioNTech vaccine, and found that the vaccine effectively neutralized the virus pathogens for a prolonged period.
“Pfizer Inc and BioNTechSE announced results from an in vitro study that provides additional data on the capability of sera from individuals immunized with the Pfizer-BioNTech Covid-19 vaccine, BNT162b2, to neutralize the SARS-CoV-2 UK strain, also known as B.1.1.7 lineage or VOC 202012/01. Results reveal that the Covid-19 vaccine elicits antibodies that neutralize pseudovirus bearing the SARS-COV-2 UK strain spike protein in cell culture. Pfizer and BioNTech are encouraged by these early in vitro study findings,” write experts.
The findings are yet to be peer-reviewed and have been published online on a preprint server. The companies have also submitted the report to a peer-reviewed journal.
The B.1.1.7 lineage is a rapidly spreading variant of SARS-CoV-2 initially detected in the UK that carries a larger than the usual number of genetic changes with 10 mutations located in the spike protein. BioNTech and Pfizer have previously published data from an in vitro analysis that evaluated one of the key mutations in the UK strain, which is also shared by the South African strain.
“The previous study had also showed efficient neutralization of the N501Y mutated spike bearing virus by sera of individuals who had received the Pfizer-BioNTech Covid-19 vaccine. The current in-vitro report investigated the full set of UK strain spike mutations,” reveal authors.
Scientists, however, suggest that further data are needed to monitor the Pfizer-BioNTech coronavirus vaccine’s effectiveness in preventing Covid-19 caused by new virus variants.
“So far, for Covid-19 vaccines, it has not been established what reduction in neutralization might indicate the need for a vaccine strain change. Should a vaccine strain change be required to address virus variants in the future, the companies believe that the flexibility of BioNTech’s proprietary mRNA vaccine platform is well suited to enable such adjustment,” note researchers.
In a separate study, investigators tested plasma taken from 20 people who got two doses of either the Pfizer/BioNTech or Moderna vaccine as part of clinical trials.
Researchers found that the vaccines produced strong antibody responses, as well as cells that keep producing new antibodies for months or years. They explain that while the mutations in the new variants of the virus, one first detected in the UK and another identified in South Africa, did allow them to evade some of the immunity induced by vaccination, it was far from a total escape.
“Taken together the results suggest that the monoclonal antibodies in clinical use should be tested against newly arising variants, and that mRNA vaccines may need to be updated periodically to avoid potential loss of clinical efficacy,” conclude authors in the report, which has not been peer-reviewed.
Both Pfizer and Moderna vaccines have been authorized by the US Food and Drug Administration (FDA) for emergency use in the US. According to the US Centers for Disease Control and Prevention (CDC), 35,990,150 total doses have been distributed across the US, and 16,525,281 doses have been administered as of January 20.