Delta mutation in Omicron BA.4, BA.5 makes Covid variant virulent but…: Expert on how to avert 4th wave in India
2 min read 09 May 2022, 10:34 PM ISTIt is clear by now that South Africa has entered the 5th wave of COVID-19 but this looks very different from the Omicron BA.1 wave, expert said

Omicron BA.4 and BA.5 contain Delta mutation, which could have made the subvariants extremely virulent but due to vaccination and immunity from the previous infection, the risk has certainly been reduced, pointed out epidemiologist Tulio de Oliveira, who had first identified the new sub-variants. “It is clear by now that South Africa has entered the 5th wave of COVID-19 but this looks very different from the Omicron BA.1 surge," he further asserted and adding, that the current situation in South Africa can guide the rest of the world on what will happen when a new wave comes.
Speaking on the current spike, the expert told WIRE, that infection is spiking but the hospitalisation rate and the deaths are very low. At present, 90% of the COVID beds and ICUs are empty. So the country is in a good position to drive through the 5th wave. The expert confirmed the new wave is driven by BA.4 and BA.5.
Can Omicron BA.4 and BA.5 cause reinfection?
Regarding the properties of the new sublineages, he added that the chances of reinfection are very high with BA.4 and BA.5 if you are unvaccinated. But infected ones who are also vaccinated (hybrid immunity), are well protected.
So, the fifth wave is happening because a large part of the population in South Africa is still unvaccinated and they are getting infected. The experts also pointed out reinfection is possible in case you had Delta since immunity, in that case, is waning.
Since BA.4 and BA.5 contain Delta mutation, is it more virulent?
BA.4 and BA.5 both have some mutation of Delta variant that could not only make the variant more transmissible than Omicron but also more virulent than Delta. On this, the expert said if we were in the first phase of the pandemic, this could have been the case. Since most of the pollution is vaccinated now and already have immunity from the previous variant, so the risk is much less now.
The highly transmissible Omicron variant of Covid-19, which was first detected in southern Africa in November last year and rapidly spread globally, is now the dominant variant, accounting for almost all new cases. WHO's latest report showed that the sub-lineages "have acquired a few additional mutations that may impact their characteristics."
The WHO has officially recorded more than 6.2 million Covid deaths worldwide since the start of the pandemic, but the true toll is believed to be far higher. However, the number of newly reported cases and deaths are now declining.