New study warns Pfizer and Moderna COVID-19 vaccines may be much less effective against South African variant

Despite the increasing global circulation of COVID-19 vaccines, variants of the virus that emerged in late 2020 could disrupt the global mission to achieve herd immunity, according to a new study approved for publication in the journal Nature.

The researchers are looking specifically at the South African COVID-19 mutation, scientifically dubbed B.1.351, analyzing whether or not these pathogens are more resistant to immune responses elicited by available vaccines.

Samples of biological fluids, namely convalescent plasma and vaccinated sera, were collected and studied for the volume of COVID-19 neutralizing antibodies contained in volunteers who recovered from documented COVID-19 infection. This highlights the risk of potential reinfection.

When analyzing sera from vaccinated volunteers – or fluids from individuals who had been fully vaccinated – the results were just as gloomy; neutralizing activity was “significantly lower” compared to B.1.351, regardless of the vaccine received by the patients.

Moderna’s vaccine candidate was shown to be 12.4 times less effective against the South African variant, and Pfizer’s was found to be approximately 10.3-fold reduced in effectiveness.

A silver lining could be that both vaccine candidates have held up well to the UK variant of COVID-19.

“The overall results are worrying, especially in light of recent reports that the Novavax and Johnson & Johnson vaccines have shown a substantial drop in efficacy in South Africa,” the authors concluded.

Originally originating from its namesake South Africa, B.1.351 quickly spread around the world. The United States Centers for Disease Control and Prevention (CDC) reports 81 confirmed cases in 20 separate jurisdictions in the United States. first known case was detected in the United States in January 2021, with official statements from the CDC calling for more research on the variant.

The UK and the South African version of COVID-19 see a mutation specifically in the spike protein binding sites, which limits 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, we may be doomed to continually continue the course of SARS-CoV-2, as we have long done with the influenza virus. », Warn the authors. “Such considerations demand that we stop the transmission of the virus as quickly as possible, redoubling our mitigation measures and accelerating the deployment of vaccines.”

In response to mutations and concerns about the effectiveness of approved vaccines, drug companies have published studies to track the evolution of variants.

In January, Pfizer announced his vaccine responds well to 16 different mutations. Meanwhile, Moderna has announced that it is working on developing a booster vaccine to help fill the gaps in its first vaccine when fighting a variant of COVID-19.