Worldover, it’s a race to vaccinate populations. This even as new variants of the SARS-CoV-2 virus emerge, mutating in ways that allow it to spread more easily, and possibly evade immune response. These variants, as the US Centers for Disease Control and Prevention points out, pose a real threat to the progress that several countries have made in the fight against COVID-19. There are several variants of concern presently, including the B.1.1.7, which was first identified in the UK, the B.1.351, which was detected in South Africa originally, the P.1, which was first seen in Brazil and the B.1.617, which is fast becoming the dominant variant in India. With many of the COVID-19 vaccines having been developed before these mutations emerged, the question is are they then effective against these new variants?
The World Health Organisation (WHO) says that COVID-19 vaccines are expected to provide “at least some protection against new virus variants because these vaccines elicit a broad immune response involving a range of antibodies and cells. Therefore, changes or mutations in the virus should not make vaccines completely ineffective.” The WHO also states that in the event that any of these vaccines prove to be less effective against one or more variants, it will be possible to change the composition of the vaccines to protect against these variants.
A recent study by Public Health England (PHE) found that two doses of Oxford-AstraZeneca vaccine and the Pfizer-BioNTech vaccine are “highly effective” against the B.1.617.2 variant that is dominant in many parts of India. The study found that the Pfizer vaccine was 88% effective, while the AstraZeneca vaccine was 60% effective. The Oxford-AstraZeneca vaccine is being manufactured in India by Serum Institute of India under the name Covishield.
Scientists at the Indian Council for Medical Research (ICMR) found that Covishield and Covaxin, which is manufactured by Bharat Biotech, generated fewer antibodies against the B.1.617 variant. However, The Hindu reported that multiple scientists noted that reduced antibodies did not mean that the two vaccines were not a ‘potent tool’ against COVID-19.
A study published in The Lancet found that the AstraZeneca vaccine is effective against the B.1.1.7 variant that was first identified in the UK. However, the AstraZeneca vaccine has been found to be less effective against the B.1.351 variant that was first seen in South Africa. The Pfizer vaccine, meanwhile, was found to be effective against the B.1.1.7 and the B.1.351 variants, according to researchers in Qatar.
Meanwhile, Moderna’ ‘tweaked’ vaccine was found to have successfully neutralised the B.1.351 variant and the P.1 variant that first emerged in Brazil. Although these results were based on a small trial, the US company hopes that the tweaked vaccine could be rolled out later this year.