SINGAPORE — A total of 350 local and imported cases of various COVID-19 variants have been detected in Singapore as of Tuesday (20 April), according to data from the Ministry of Health (MOH).
These include eight local cases of two variants – one of the South African strain and seven cases of the UK variant – along with 342 imported cases with various strains.
The ministry was on Thursday responding to media queries by Yahoo News Singapore in its latest update since end-January on variant cases here.
It also marks the first time authorities officially confirmed that other variants apart from the UK strain, or B.1.1.7, were detected here. The MOH did not specify in its response when the cases of the other variants were first identified, as well as the cases' current prognoses.
The sole local – and currently unlinked – case of the South African variant is a 23-year-old male Indian national who resides in a dormitory at Brani Terminal Avenue.
The work permit holder is employed at the Seafront Support Company as a lashing specialist. He was detected when he was tested on 7 April and was confirmed as a case four days later. The man received his first dose of COVID-19 vaccine on 25 January and the second dose on 17 February.
As he works in the marine industry, he was exposed to potentially infectious sources from ships visiting Singapore, said the MOH.
The seven cases of UK variant include five confirmed in January. Among the latter group are a 24-year-old Korean man, a work permit holder who works at Azur at Crowne Plaza Changi Airport, and a 39-year-old Singaporean man and his 39-year-old Singaporean spouse. The couple had visited Jewel Changi Airport on 31 December last year, while the Korean man was at Changi Airport Terminal 3 on the same day.
The other two cases who were infected in January are a 43-year-old Malaysian female work permit holder and a 20-year-old Singaporean man who both work at Azur.
The two remaining cases of the UK variant, who were confirmed in February, are a 43-year-old Singaporean man, the husband of a 41-year-old Singaporean who works as a cabin crew member with Singapore Airlines, as well as a 35-year-old Indonesian woman who is employed as a foreign domestic worker by the couple.
Authorities had said then that the Singaporean woman tested preliminarily positive for the UK strain and classified her as an imported case.
"All necessary public health actions have been taken promptly to isolate and ringfence these cases. While there had been transmission to members of the same household for three cases amongst these eight cases, there has not been any further community spread," said the MOH.
The 342 imported cases from various countries with the strains had already been placed on stay-home notice or isolated upon their arrival here, it added.
They include 46 cases of the Indian "double mutant" variant, 130 of the South African variant, five of the B.1.525 mutation, 155 cases of the UK variant, and six of the various Brazilian strains – P.1, P.2, and P.3. Separately, one imported case tested preliminarily positive for the UK strain.
Yahoo News Singapore on Wednesday reported that the first case of the Indian variant in Singapore was detected on 26 February, while the first case of the South African variant was detected on 7 February, according to the Global Initiative on Sharing All Influenza Data (GISAID), the world's largest database of novel coronavirus genome sequences.
The National Public Health Laboratory, one of the National Centre for Infectious Diseases' public health units, last updated the database a week ago, according to checks by Yahoo News Singapore. The laboratory has been conducting whole genome sequencing and phylogenetic analysis of COVID-19 cases here.
'Not possible' to provide real-time info on variant cases
At a COVID-19 multi-ministry taskforce media conference on Thursday, Yahoo News Singapore asked MOH director of medical services Kenneth Mak why the ministry had not included updates on variants of concern in its daily reports on COVID cases in Singapore.
Acknowledging that such variants have been reported with "a high degree of frequency" in the Republic, he said that this is because time is needed to determine which strain of the virus that a case was infected with.
"The results do not come out at the same time when we report the cases that we diagnose and detect, and therefore it's not possible to give you that information in real-time," said Associate Professor Mak, who added that aggregate numbers will be given to the public at intervals.
He noted that the majority of these variants are emerging in imported cases and that the risk of community spread in these cases is low as they were detected during their isolation or quarantine period.
At the same press conference, health minister and taskforce co-chair Gan Kim Yong stressed that authorities here have to "closely monitor the global situation and look out for local infections including the presence of new variants", given the worldwide emergence of new strains.
"Against this global backdrop of rising cases and emerging variants of concern, we are on heightened alert. The situation in Singapore could escalate quickly if we let our guard down," he said, adding that Singapore will be tightening border measures given the deteriorating situation.
The taskforce also announced at the press conference that it will ban all long-term pass holders and short-term visitors with recent travel history, including transit history, to India within the last 14 days, starting from 11.59pm on Friday until further notice.
Authorities closely monitoring vaccine efficacy against variants
In its statement, the MOH noted that it will "continue to closely monitor the evolving COVID-19 situation and global and local studies of vaccine efficacy against various COVID-19 variants".
Currently, the Pfizer-BioNTech and Moderna COVID-19 vaccines are the only two authorised for use here.
Out of many thousands, three variants of concern – the UK, South African, and Brazilian strains – have attracted international attention due to their increased transmissibility and virulence.
The trio share a particular mutation – named N501Y – that is thought to make them more contagious. This mutation occurs on the virus' spike protein, which attaches to human cells.
The South African and Brazilian variants, as well as variant of interest B.1.525, share another key mutation – named E484K – that is suspected to reduce the immunity acquired either by a past infection or a vaccine.
The UK variant first emerged in September last year and is said to be up to 70 per cent more transmissible than previously dominant variants. According to WHO data, the strain has spread to over 130 countries.
The South African variant – or B.1.351 – was detected in August. It is thought to be 1.5 times more transmissible and can potentially increase the risk of in-hospital mortality by 20 per cent, according to the WHO. It has spread to over 80 countries, and had been listed as not officially verified in Singapore in WHO weekly epidemiological reports.
Studies have shown the Brazilian variant to be as much as 2.5 times more contagious than the original virus and more resistant to antibodies.
The particular variant, which emerged in December last year in or around the northern Brazilian city of Manaus, has spread to over 50 countries. It was first identified in Japan, where it was detected in travellers returning from Brazil.
Global concerns have also been sparked by the emergence of the "double mutant" Indian strain – or B.1.617 – with the E484Q and L452R mutations, which appears to be the main driving force behind a surge in new cases in the country. The variant of interest, labelled as such by the WHO, has been detected in at least 17 countries.
Preliminary studies show that the vaccines from AstraZeneca and China's Sinovac are partly effective against the Brazilian variant. The Pfizer-BioNTech vaccine, one of two approved for use here, has also been proven effective against the strain, but studies have shown that it is less effective against the South African variant.
Two new Moderna vaccines designed to protect against the South African and Brazilian variants have yielded promising results when tested in mice, according to recent data. The original Moderna vaccine is approved for use in Singapore.
As of last Sunday, some 1.36 million individuals in Singapore have received at least one dose of either the Pfizer-BioNTech or Moderna vaccine, with more than 849,700 of them having received their second dose of the same vaccine and completed the full vaccination regimen.
A breakdown of how many of each vaccine type is administered here is not publicly available.
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