CAMBRIDGE, Massachusetts, USA – Moderna said today that its vaccine for Covid-19 protects against emerging variants of the virus, but as a precaution, it is testing a possible booster dose against a strain discovered in South Africa.
In today’s announcement, Moderna CEO Stephane Bancel said the move is “out of precaution” after preliminary lab tests suggested his injection produced a weaker immune response to that variant.
Vaccine manufacturers have been testing their treatments against the mutated strains, including two that first emerged in Britain and South Africa. In a study conducted with the US National Institutes of Health, Moderna used blood samples from eight vaccinated and some immunized monkeys in laboratory tests against mutated viruses.
The vaccine was effective against both variants, but the researchers found a six-fold drop in levels of “neutralizing antibodies” against the South African strain. Moderna said that while the vaccine continued to protect even at lower levels, the company has begun developing a booster vaccine targeting that new strain, called variant B.1.351. Additionally, Moderna will test whether it might be helpful to simply administer an extra dose of the original vaccine.
Pfizer, which makes a similar Covid-19 vaccine, has previously reported that its injection appears effective against the British strain as well. But other research has raised questions about the South African variant.