BA4 and BA5 Covid-19 variants reach Singapore

 

Singapore has detected two local Covid-19 cases infected with the BA4 variant, and one local case infected with the BA5 variant, according to the republic’s Health Ministry.

“These are the first community cases confirmed to be infected with the BA4 and BA5 variants,” the ministry said on its website.

It noted that the European Centre for Disease Prevention and Control has recently classified them as variants of concern.

The ministry said the presence of the two variants in these three cases was detected via further testing of polymerase chain reaction (PCR) positive samples and confirmed through whole genome sequencing (WGS).

“All cases were either asymptomatic or had mild symptoms such as fever, cough, runny nose and sore throat; and did not require hospitalisation. They are fully vaccinated, and had earlier received their booster dose,” it added.

All three cases had self-isolated upon testing positive for Covid-19, the ministry said, adding that they did not have any reported exposure to vulnerable settings.

According to the ministry, BA4 and BA5 were first reported by South Africa in early 2022 and have since become the dominant variants there.

Both lineages contain mutations in the spike protein which appear to confer greater immune escape properties and higher transmissibility compared to the BA1 and BA2 causing the Omicron wave earlier this year, it said.

However, emerging real-world evidence from other countries supports that BA4 and BA5 infections will likely give rise to similar clinical outcomes, compared to previous Omicron lineages, it added.

Citing the World Health Organisation, the ministry said at least 1,000 cases of BA4 and BA5 have been reported in at least 16 countries as of May 11.

“We will step up local surveillance efforts and continue monitoring the spread of BA4 and BA5 in Singapore,” said the ministry.

- Bernama