A silver lining could be that both of the vaccines held up well against the UK Covid-19 variant
Although vaccines for Covid-19 has increased in global circulation, a new study now suggests that vaccines produced by Pfizer and Moderna may not prove to be much effective against the South African variant, scientifically dubbed B.1.351.
The study, which has been approved for publishing in the journal Nature, has also raised concerns that such new mutations of the coronavirus that emerged in late 2020 may disrupt the world’s mission to achieve herd immunity through available vaccines.
Researchers specifically studied B.1.351 variant, where they analyzed whether or not these pathogens are more resistant to immune responses prompted by the available vaccines.
Samples of biological fluids, namely convalescent plasma and vaccine sera, were collected and studied for the volume of Covid-19-neutralizing antibodies contained among volunteers who recovered from a documented Covid-19 infection, the study said.
When analyzing volunteer vaccinee sera — or fluid from individuals who had been fully vaccinated — the results were similarly grim; neutralizing activity was “significantly lower” against B.1.351, regardless of which vaccine patients received, which highlights concern for potential reinfection
Moderna’s vaccine candidate was found to be 12.4 times less effective against the South African variant, and Pfizer’s was found to have a reduced effectiveness by about 10.3 times.
A silver lining could be that both of the vaccines held up well against the UK Covid-19 variant.
“The overall findings are worrisome, particularly in light of recent reports that both Novavax and Johnson & Johnson vaccines showed a substantial drop in efficacy in South Africa,” the authors concluded in the study.
First originating in its namesake South Africa – B.1.351 – has quickly spread across the globe.
After being first detected in the US on January 2021, the country’s Centers for Disease Control and Prevention (CDC) reports 81 confirmed cases across 20 separate jurisdictions.
Both the UK and the South African version of COVID-19 see mutation specifically in the spike protein’s binding sites, which constrains how antibodies produced by the human immune system can fight the virus.
“If the rampant spread of the virus continues and more critical mutations accumulate, then we may be condemned to chasing after the evolving SARS-CoV-2 continually, as we have long done for influenza virus,” the authors warn.
In response to the mutations and concerns over efficacy of approved vaccines, pharmaceutical companies have issued studies to monitor how the variants are developing.
“Such considerations require that we stop virus transmission as quickly as is feasible, by redoubling our mitigation measures and by expediting vaccine rollout,” they added in the study.
In January, Pfizer announced its vaccine responds well against 16 different mutations.
Meanwhile, Moderna announced that it was working on developing a booster vaccine to help bridge any gaps its first vaccine misses when fighting a Covid-19 variant.