3 Singapore COVID cases of new BA.4 and BA.5 Omicron sub-variants found: MOH

omicron BA.4 corona virus variant
Omicron BA.4 and BA.5 COVID-19 sub-variants. (ILLUSTRATION: Getty Images)

SINGAPORE — Singapore has detected three local COVID-19 cases who were infected with two new Omicron sub-variants, the Ministry of Health said on Sunday (15 May).

Two of the cases are infected with the BA.4 variant, and one case is infected with the BA.5 variant – both of which are the first such infections in the community. The European Centre for Disease Prevention and Control has recently classified BA.4 and BA.5 as variants of concern, MOH said.

The detection of the variants was confirmed via further testing of polymerase chain reaction (PCR) positive samples and whole genome sequencing.

All the cases were either asymptomatic or had mild symptoms such as fever, cough, runny nose and sore throat. They are fully vaccinated, and had received their booster dose. They had self-isolated after testing positive for COVID-19.

BA.4 and BA.5 have become the dominant variants in South Africa after they were first reported early this year.

They contain mutations in the spike protein that appear to make them more contagious than the BA.1 and BA.2 variants that caused the Omicron wave earlier this year.

“However, emerging real-world evidence from other countries supports that BA.4 and BA.5 infections will likely give rise to similar clinical outcomes, compared to previous Omicron lineages,” MOH said.

At least 1,000 cases of BA.4 and BA.5 have been reported in at least 16 countries as of Wednesday, according to the World Health Organization.

On Sunday, Singapore detected a total of 2,594 local COVID-19 cases and 57 imported cases, with one reported death from the infection.

The weekly infection growth rate – or ratio of community cases for the past week over the week before – fell for a fourth consecutive day. It dropped to 1.39 on Sunday from 1.42 a day earlier. A figure of over one means that the number of new weekly cases is on the rise.

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