Two new sublineages of the Omicron coronavirus variant – BA.4 and BA.5 – are capable of dodging antibodies from earlier infection well enough to trigger a new wave; South African scientists have found. The variants, however, are far less able to thrive in the blood of people vaccinated against Covid-19, Reuters reported quoting the scientists.
The two new sublineages of the Omicron; were last month added to the monitoring list of the World Health Organization (WHO).
The study conducted by scientists from multiple institutions analysed the blood samples from 39 participants previously infected by Omicron when it first emerged at the end of last year.
Among the participants, 15 were vaccinated – eight with Pfizer’s shot; seven with J&J’s – while the other 24 were not.
“The vaccinated group showed about a 5-fold higher neutralisation capacity… and should be better protected;” Reuters quoted the study – a pre-print of which was released over the weekend.
In the unvaccinated samples, an almost eight-fold decrease in antibody production when exposed to BA.4 and BA.5; compared with the original BA.1 Omicron lineage was observed, said the report.
Blood from the vaccinated people showed a threefold decrease.
South Africa may be entering a fifth Covid-19 wave earlier than expected, officials and scientists said on Friday; blaming a sustained rise in infections that seems to be driven by the BA.4 and BA.5 Omicron sub-variants.
Only about 30% of South Africa’s population of 60 million is fully vaccinated.