Two sub-lines of Omicron cause a new wave of epidemics in South Africa

Inside the Center for Disease Research in Cape Town, South Africa – Photo: REUTERS

On May 3, CNN quoted information from South Africa’s National Institute of Infectious Diseases as saying that BA.4 and BA.5 accounted for 60% of new COVID-19 cases in the country as of the end of April. -2022. Before that, South Africa witnessed a new wave caused by 2 sub-currents of Omicron in two weeks with the number of new cases tripled, according to statistics from Johns Hopkins University.

According to statistics page Worldometer, South Africa recorded 3,785 new cases and 7 deaths on 3-5 days.

A recent (unreviewed) study suggests that these two sublines are able to avoid the natural immunity produced after infection with the Omicron variant and the immunity generated from the COVID-19 vaccination.

Research by South African scientists shows that in people who have been infected with Omicron, their levels of neutralizing antibodies are reduced by nearly eight times when tested with sub-variants BA.4 and BA.5. For people who had been vaccinated and then had a breakthrough infection, their levels of neutralizing antibodies were reduced by about three times during the same trial.

South Africa’s Health Minister Joe Phaahla said that although the number of hospital admissions in the country increased, the rate of serious illness or death had not changed.

He also said that the country’s health authorities have not yet issued a warning for any new variant other than Omicron. Meanwhile, infectious disease expert Richard Lessells said that the new wave in South Africa could be due to the population’s immunity from previous infections dwindling.

According to CNN, the BA.4 series is now available in 15 countries, while BA.5 is detected in 13 countries. These strains were detected in some states of the US and Canada but were not significant. On May 3, Australia also said it was closely monitoring after detecting a number of new cases of Omicron sub-lines in two states.

The BA.4, BA.5 variants of Omicron have not been recorded in Vietnam yet

TTO – Immediately after the World Health Organization (WHO) announced the monitoring of a number of infections with two new sub-variants of the Omicron variant, BA.4 and BA.5, discussed with Tuoi Tre Online, a representative of the Department Preventive medicine said that Vietnam has not yet recorded this variant.