Bangladesh detects cases of omicron sub-variants BA.4, BA.5

Researchers at the Jashore University of Science and Technology have found omicron sub-variants BA.4 and BA.5 in samples from two Bangladeshi coronavirus patients.

The late sub-variants, which now account for more than 21 percent of new cases in the US, contain mutations not present in the BA.1 and BA.2 versions of omicron.

Those newer sublineages "notably evade the neutralizing antibodies elicited by SARS-CoV-2 infection and vaccination," Chinese researchers found in test-tube experiments.

Professor Dr Iqbal Kabir Jahid of the university's genome centre and head of microbiology department said both cases were locally transmitted. The patients are male and aged 44 and 79.

One of them received a booster dose of the coronavirus vaccine after the first two shots. The other had two doses. One of the patients has been hospitalised while the other is receiving treatment at home.

They have mild symptoms, such as fever, sore throat, cold, and cough, according to Dr Iqbal.

He said scientists believe the sub-variants are responsible for a third wave of infections in India.

"Vaccinated people are also getting infected with these sub-variants. Scientists think they can cause more infections than other sub-lineages in the future."

"BA.4 and BA.5 have similar mutations in their spike proteins like the early omicron sub-variants. The new sub-variants also have mutations in amino acid No. 452 in the spike proteins, just like the delta variant."

Vice-Chancellor Prof Md Anwar Hossain said he sees no alternative to strictly practicing preventive measures such as masking and social distancing because the sub-variants can evade the immune system.