By Sola Ogundipe
Shortly after Pfizer announced that it is developing a booster to help its COVID-19 vaccine to protect against new highly-infectious variants from Brazil and South Africa, Moderna Inc has said that it is advancing its own COVID-19 vaccine with a booster to combat the South African variant.
Lab tests done by both firms suggest each of their vaccines will likely work well enough against the variants from the UK (B117) and South Africa to be protective.
But Moderna’s tests suggested the South African variant might make their shot less effective, or cut the amount of time for which the vaccine works.
Minnesota reported the first case US of the Brazilian P1 COVID-19 variant even as cases of the UK variant have been detected in the US. No cases of the South African variant have been detected in the US so far, but the Brazilian variant shares mutations with it that could make vaccines less effective against either.
Pfizer announced last week that its vaccine was effective against the UK variant that has become dominant in the UK and has been detected in at least 25 states.
Its lab studies showed that antibodies triggered by the vaccine successfully bind to the mutated spike protein that makes the variant about 70 percent more infectious.
The firm noted that the lab study did not test the vaccine against the whole, live virus, but said the findings make it likely that COVID-19 caused by the UK virus variant will also be prevented by vaccination with its shot.
It also noted that the South African variant shares the mutation seen in the UK’s spike. However, the South African variant has additional mutations, including some of its spike protein that is also present in the Brazilian variant.
The mutations of the South African and Brazilian variants make them about 50 per cent more infectious, and may also help the virus to evade antibodies triggered by vaccines or prior infection.