New COVID-19 variants: Do the UK and South Africa virus strains pose a danger to Singapore?

New COVID-19 variants: Do the UK and South Africa virus strains pose a danger to Singapore?

People in masks at Changi Airport 12
Airport staff members are seen in personal protective equipment and protective face masks at Changi Airport Terminal 1. (Photo: Calvin Oh)

SINGAPORE: Two new variants of the virus that causes COVID-19 have raised alarm around the world as they are said to be more contagious, making it even harder to stop the spread of the disease. 

While variants of SARS-CoV-2 are to be expected as they replicate and adapt to their human hosts, these particular strains are “of concern”, said the World Health Organization (WHO).

One, known as B.1.1.7, was reported by the United Kingdom in December, while another one named 501Y.V2 has spread widely in South Africa.

The detection of the variants has led to tightened travel restrictions worldwide for visitors from the UK and South Africa, as well as fresh lockdowns in Europe.

In Singapore, citizens and permanent residents returning from the UK and South Africa will have to serve an additional seven days of self-isolation on top of a 14-day stay-home notice.

READ: All travellers, including Singaporeans, to take COVID-19 test upon arrival in Singapore

Here’s what we know about the SARS-CoV-2 variants so far, and the implications for Singapore: 

WHAT ARE THE TWO VIRUS VARIANTS?

The United Kingdom reported B.1.1.7 or VOC 202012/01 to the WHO on Dec 14, but it had been spreading months before that and was traced to Kent in September.

The variant found in South Africa is called B.1.351 or 501.V2, after an N501Y mutation in the virus’ spike protein. It was first reported to the WHO on Dec 18 after being detected in October, and has since largely replaced other COVID-19 virus strains in South Africa.

The variants may not necessarily have originated from the UK and South Africa although they were first detected there. Both are potentially more transmissible but do not seem to cause more severe disease. 

WHERE HAVE THEY SPREAD?

B.1.1.7 was responsible for more than 50 per cent of cases in southeast England from October to December and has been detected in more than 50 countries, including Singapore and Malaysia.

Dr Nikki Kanani, Medical Director of Primary Care for NHS England has said that as many as one in 30 people there could be carrying this new variant of COVID-19. The UK has seen case numbers reach record highs even as vaccination has started. 

READ: Fast-spreading UK COVID-19 variant could be dominant in US by March: CDC

The South Africa virus strain was first discovered in Nelson Mandela Bay on the east coast - then spread rapidly to the south and south east of the country.

Up to 90 per cent of new cases in the country are carrying the mutant variant, according to health authorities, driving a surge in infections that threatens to overwhelm South Africa’s healthcare system.

It has been found in more than 22 territories, including Malaysia, according to cov-lineages.org.

WHAT’S THE SITUATION IN SINGAPORE?

Several people have now preliminarily tested positive for the B.1.1.7 strain in Singapore.

The first case recorded in Singapore, on Dec 24, was a 17-year-old Singaporean woman who had returned from Britain. On Dec 30, a Singapore Airlines pilot and a work pass holder who arrived from the UK also preliminarily tested positive for the B117 strain, MOH said then.

On Jan 6, MOH reported that a 24-year-old South Korean man who works at Azur at Crowne Plaza Changi Airport also tested positive for the UK strain. His job was to deliver pre-packed meals to air crew and hotel guests.

Subsequently, a Singaporean colleague of his – a 20-year-old man - also tested preliminarily positive for the B.1.1.7 strain of the virus. The hotel is now closed until Jan 21 as a precaution. COVID-19 tests for 234 employees working there all came back negative.

CNA has contacted the Ministry of Health for more information on the local situation.

READ: 30 new COVID-19 cases in Singapore, including 2 in community, forming new cluster linked to para-vet

WHAT MAKES THEM MORE TRANSMISSIBLE?

The UK and South Africa variants are similar in that they share a common N501Y mutation in the spike protein, which the virus uses to infect cells. 

The mutation means they can better bind to human cells – thus making it easier for them to infect us. Studies have shown that the UK variant could be 40 to 70 per cent more transmissible.

A 3D print of a spike protein of SARS-CoV-2, the virus that causes COVID-19 -- in front of a 3D
A 3D print of a spike protein of SARS-CoV-2, the virus that causes COVID-19 -- in front of a 3D print of a SARS-CoV-2 virus particle AFP/Handout

Experts have warned that this means the proportion of the population that needs to be vaccinated to achieve herd immunity will be greater.

The South African variant also has two mutations that are absent in the UK variant, says Dr Julian Tang, a clinical virologist at the University of Leicester. One of them - mutation E484K - has caused concern as it can hinder the action of antibodies against the virus.

WHAT ARE THE IMPLICATIONS FOR SINGAPORE?

If these variants start to circulate freely in Singapore, there will be a risk of an accelerated spread of COVID-19 across the community, said Professor Teo Yik Ying, dean of the Saw Swee Hock School of Public Health.

“This is why it is even more important now than ever, to ensure that we keep up with our personal safe management measures such as proper mask-wearing and social distancing,” he said.

Given that Singapore has allowed the resumption of more social activities and larger gatherings, should the variants spread in the country, it is possible that there will be much faster and broader infection across the community, before contact tracing, isolation and testing protocols can kick in. 

“However, if people continue to keep up with their measures, the risk of an uncontrolled outbreak in Singapore is still small,” Prof Teo added.

Professor Dale Fisher of Yong Loo Lin School of Medicine at the National University of Singapore said that entry points to Singapore such as ports and airports are more vulnerable so these sites need to be "extra vigilant".

Singapore has already imposed more border restrictions such that travellers from the UK and South Africa have to self-isolate for seven days on top of a 14-day stay-home notice at a hotel.

All travellers will also need to take a COVID-19 test on arrival. This will help detect cases earlier and "offload some risk" from quarantine hotels, said Prof Fisher.

"These people would be cared for in hospital or a community care facility and decrease the risk of spread at the quarantine hotels," he added.

DO VACCINES WORK AGAINST THEM?

Prof Teo said that there is the secondary concern that these new variants, or subsequent emerging ones, may be resistant to existing vaccines. This is currently an area of active research.

Pfizer and BioNTech have said that a laboratory study shows that its COVID-19 vaccine works against the key mutation in the new variants of the coronavirus. The COVID-19 vaccine developed by Moderna is also expected to also be effective against the B.1.1.7 variant. 

There is a chance that changes in the South African variant may affect the effectiveness of vaccines to some extent but it is too soon to know for sure, said scientists. They assure that the vaccines can be modified, if needed, in as little as six weeks.

READ: BioNTech says COVID-19 vaccine 'neutralises key mutation' in UK, South Africa strains

“It is entirely possible that there will be future mutated strains that will be resistant to present vaccines. If that is indeed the case, then vaccines will need to be modified continuously and regularly, very much as what we do with influenza vaccines,” said Prof Teo.

However, if the virus becomes more contagious, then more people would need to be vaccinated to achieve herd immunity.

Saw Swee Hock School of Public Health's vice dean of research Associate Professor Alex Cook said that if the new variant is 50 per cent more contagious, then Singapore should probably be aiming for as close to 100 per cent vaccination coverage as possible, within the constraint that some people cannot take the vaccines.

Prof Fisher added: "These (COVID-19) threats are constant and it’s another reason to vaccinate when given the opportunity."

MORE VARIANTS POSSIBLE

Could new and more dangerous variants arise? Director-General of the WHO Tedros Adhanom Ghebreyesus has said that the more the COVID-19 virus spreads, the higher the chance that it will evolve.

"Most notably, transmissibility of some variant of the virus appears to be increasing. This can drive a surge of cases and hospitalisations," he said. 

"But we need to follow the public health basics now more than ever … You might get fed up of hearing it, but the virus is not fed up with us. Limiting transmission limits the chance of dangerous new variants from developing."

Brazil is now also dealing with a new, potentially more contagious, coronavirus variant called P1 that originated in Amazonas and prompted Britain on Thursday to bar entry to Brazilian travellers. This has also been detected in Japan in travellers from Brazil. 

If indeed there is an emergence of variants that are resistant to present vaccines, then there is a real risk that the global pandemic will not be that successfully contained by the cocktail of vaccines and community safe management measures, said Prof Teo. 

“If that is the case, Singapore will continue to have to maintain strict vigilance on our borders,” he said.

READ: Global death toll nears 2 million as WHO battles new virus strains

READ: UK imposes travel restrictions amid worries of new COVID-19 variant

While Singapore has already imposed a longer self-isolation period for incoming travellers from the UK and South Africa, these border control measures may need to continue to be revised according to the geographical spread of these new variants and any emerging strains subsequently, he added.

Associate Professor of Infection and Immunity Luo Dahai from Nanyang Technological University's Lee Kong Chian School of Medicine said that the COVID-19 pandemic shows no sign of slowing down. 

“The virus mutates and evolves. The production and distribution of the vaccines are not sufficient and fast enough. There is also strong resistance to the controlling measures and vaccination efforts in certain countries. Singapore is not and cannot go in isolation – so we must remain vigilant,” he said.

More than 2,024,656 people have died from the virus across the world, with nearly 95 million cases recorded, according to an AFP tally based on official sources as of Sunday.

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Source: CNA/hm(gs)

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