New sub-lineage of Omicron variant able to evade immune system
New laboratory research shows that the BA.4 and BA.5 strains are able to evade both the natural immune system that develops after infection and the "barrier" created by COVID-19 vaccination.
According to Bloomberg news site, last April, South African scientists discovered two new sub-lines BA.4 and BA.5 ofOmicron variantat a time when the number of COVID-19 cases increased suddenly.
A new laboratory study shows that these variants are able to evade both the natural immunity gained after infection and the "barrier" created by COVID-19 vaccination.
The study was conducted at the Africa Health Research Institute laboratory in Durban with 24 people who had been infected with the original Omicron variant of the SARS-CoV-2 virus but had not been vaccinated against COVID-19 and 15 people who had been vaccinated.
Blood samples collected showed that in people who had been infected with Omicron, the amount of neutralizing antibodies decreased by nearly eight times when tested against the BA.4 and BA.5 sub-variants. For those who had been vaccinated, the amount of neutralizing antibodies decreased by about three times during the same test.
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| Microscopic images provided by the US National Institute of Allergy and Infectious Diseases show SARS-CoV-2 virus particles in a sample of a COVID-19 patient. Photo: AFP/TTXVN |
However, the amount of these antibodies is extremely low in unvaccinated people. Therefore, this group is not resistant to the two new sub-variants, thereby potentially causing a new wave of infection with BA.4 and BA.5.
The study results were published in the context of an increase in new cases in South Africa - the country experiencing its first wave of COVID-19 outbreaks caused by the Omicron variant after this variant was first detected here and in neighboring Botswana.
The Africa Health Research Institute's research lab was the first to test for the original Omicron variant of the SARS-CoV-2 virus based on blood sample analysis.
