Does Moderna's Covid-19 vaccine work against South Africa strain?

Both Pfizer and Moderna have carried out early lab tests on the efficacy of their existing vaccines on the new UK and South African variants of the novel coronavirus.

Does Moderna Covid-19 vaccine work against South Africa strain?

On 18 December, optimism was running high in the face of the coronavirus pandemic as the FDA announced it had issued emergency use authorization for Moderna’s Covid-19 Vaccine, which became the second novel coronavirus vaccine to be approved by the US drug authority following approval of Pfizer-BioNTech’s vaccine a week prior.

However, in a cruel case of timing, on the same day the FDA announced the approval of Moderna’s MRNA vaccine, national authorities in South Africa warned that they had detected a new variant of coronavirus rapidly spreading in three provinces of the country, which has since become a major worry for vaccine makers, the WHO and health authorities around the world as this new strain has now spread to several countries.

South African variant not yet detected in US

Reports of this new South African variant emerged just days after the detection of a more infectious and presumably more deadly strain in the UK. While cases of the UK strain have been detected in the United States, US experts are rather more worried about the South African variant. Although it has yet to be identified among US cases of the novel coronavirus.

In a bid to stop the South African variant entering the US, president Joe Biden imposed a ban on travel on most non-U.S. citizens entering the country who have recently been in South Africa, which came into effect last Saturday.

Joe Biden has imposed a South Africa travel ban.

Moderna test efficacy of vaccine on South African variant

Both Pfizer and Moderna have carried out early lab tests on the efficacy of their existing vaccines on the new UK and South African variants, labelled B.1.1.7 and B.1.351, respectively. Both companies have found that their current vaccines are almost equally as effective on the new UK strain as they are against earlier variants upon which they were developed. However, both vaccines were found to offer slightly less protection against the South African variant.

Moderna’s laboratory tests found that while blood samples exposed to the new variants appeared to have sufficient neutralizing antibodies to stop both strains, the neutralizing effect was weaker for the South Africa variant than for the UK one. Moderna has therefore concluded that protection against the South Africa variant might not last as long, although the company remains confident that their current vaccine is still sufficiently effective against the B.1.351 strain.

“For the South Africa strain we still see a very high level of antibodies … but it is indeed lower than the traditional strain and the B.1.17 (UK variant),” said Moderna CEO Stephane Bancel in an interview with CNBC.

Bev Belgau, who got in line with her husband Ron at 10pm the previous evening, receives her first dose of the Moderna COVID-19 vaccine at a free coronavirus disease (COVID-19) vaccine clinic for people 70 and older and their spouse or partner, run by the Jamestown S'Klallam Tribe in Sequim, Washington, US, January 23, 2021.

Moderna testing new vaccine booster candidate

Moderna has subsequently began testing a new version of its vaccine that could be used as a booster shot against the variant in South Africa. “We’re doing it today to be ahead of the curve, should we need to,” Dr. Tal Zaks, Moderna’s chief medical officer, told the New York Times. “I think of it as an insurance policy.” “I don’t know if we need it, and I hope we don’t,” he added.

While Moderna hopes it will not need the insurance policy of its new booster dose against the South African strain, it is preparing for the possibility that other mutations of the virus may emerge which could be resistant to current vaccines. As such, the company is not resting on its laurels and will continue to test new vaccine candidates as new strains potentially emerge.

“Out of an abundance of caution and leveraging the flexibility of our mRNA platform, we are advancing an emerging variant booster candidate against the variant first identified in the Republic of South Africa into the clinic to determine if it will be more effective to boost titers against this and potentially future variants,” Bancel said in a statement.