https://t.co/BoZ3WkIH5X 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. 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.