SINGAPORE, Nov 26 — Countries around the world, including Singapore, are on high alert over a new coronavirus strain first discovered in South Africa and believed to be more transmissible than the original virus and possibly vaccine-resistant, with some European and Asian nations tightening travel restrictions today. Financial markets also took a battering on the news.
South African scientists said yesterday that they had detected a new B.1.1.529 variant of the Sars-CoV-2 coronavirus that causes Covid-19. The new strain is in small numbers and they are working to understand its potential implications.
Singapore announced today that it would ban or impose restrictions for travellers who had recently been to seven African countries, including South Africa and Botswana, two countries where cases have been found.
The World Health Organization (WHO) will today convene a meeting in Geneva, Switzerland, to decide if the new variant will be designated as a variant of interest or of concern. A variant of concern means that the authorities regard it as potentially more problematic.
Should it be designated as a variant of concern, it is expected to be named the “Nu” variant, after the Greek letter “N”, in the tradition of naming the various strains after letters of the Greek alphabet.
But what do we know so far about this new variant, to what extent has it spread around the world, and should Singapore be concerned about it?
TODAY takes a closer look.
What do we know about the variant so far?
Scientists in South Africa have said that the new variant has a “very unusual constellation” of mutations, which are of concern because they could help it evade the human body’s immune response and make it more transmissible.
The New York Times reported that the B1.1.529 variant has more than 30 mutations in the spike protein alone. On the ACE2 receptor, which is the protein that helps to create an entry point for the coronavirus to infect human cells, the new variant has 10 mutations.
By comparison, the Beta variant has three and the Delta variant has two.
The Africa Centres for Disease Control and Prevention (Africa CDC) said in a statement yesterday that some of the mutations on the new variant have also been detected in previous variants, such as Alpha and Delta, and have been associated with increased transmissibility and immune evasion.
The organisation added that many of the other identified mutations are “not yet well-characterised and have not been identified in other currently circulating variants”.
However, it stressed that more investigations are underway to determine the possible impact of the mutations on the virus’ transmissibility, its impact on vaccine effectiveness and its ability to evade immune response to cause more severe or milder disease.
Professor Paul Tambyah, president of the Asia Pacific Society of Clinical Microbiology and Infection, told TODAY that the main concern with the variant so far is that there are four mutations on it associated with immune escape.
“This means that many of the monoclonal antibody drugs currently on the market may not work in neutralising this virus,” he said.
Monoclonal antibodies are laboratory-made proteins that act like antibodies in helping the body to fight off infection. They can be used to treat patients who are mildly sick but at risk of severe illness.
Examples of such drugs include sotrovimab, which was made available to healthcare institutions here in September.
However, Prof Tambyah said that the body’s natural immune response is multifaceted and includes T-cells and the “innate immune response”, which act as barriers that keep harmful materials from entering the human body.
“So, it is unlikely that the overall immune response will be affected much, unlike (with) the antibody drugs.”
Dr Leong Hoe Nam, an infectious diseases expert from Rophi Clinic, said that even if the new variant diminishes vaccine efficacy, having more antibodies from a third booster dose could still confer adequate protection against B1.1.529.
“The quality of the vaccine cover may be less adequate, but what we have done with the three shots of boosters increases the quantity (of antibodies),” he said. “With the sheer overwhelming quantity of antibodies, you can block off the infection.”
Where has it spread to and how have countries reacted?
So far, nearly 100 genetic sequences of the variant have been reported. This refers to a detailed analysis of the virus by scientists.
The Africa CDC said in its statement that there have been 77 fully confirmed cases in Gauteng province in South Africa — the nation’s most populous with 15 million people, including its largest city of Johannesburg — and four cases in Botswana.
However, BBC news reported on Friday that the variant may have spread more widely, with scientists estimating that the it could account for 90 per cent of the Covid-19 cases in Gauteng.
Yesterday, Hong Kong reported two cases of the B1.1.529 variant, including a 36-year-old man who had flown from South Africa on Nov 11. He later tested positive for the virus and then infected a 62-year-old man.
Other than Singapore, several other countries have also imposed tightened measures.
Reuters news agency reported that Britain has banned flights from South Africa and neighbouring countries, and it has asked British travellers who have recently returned from the area to quarantine. The European Commission’s chief Ursula von der Leyen has said that the European Union also aimed to halt air travel from the region.
Italy has imposed an entry ban on people who have visited southern African states in the last 14 days, and Germany will declare South Africa a virus variant area, a health ministry source said.
Japan also tightened border controls for visitors from South Africa and five other African countries, while Taiwan said that travellers from “high-risk” southern African countries will have to go into quarantine.
Is it a concern for Singapore?
Infectious disease experts here agreed that given Singapore’s strategy of living with the coronavirus, should the new variant spread around the world, it would not be a matter of “if” but “when” the variant would breach Singapore’s borders.
“I have no doubt that the containment of this variant will fail, and given that Singapore is going endemic, we must prepare for the virus’ arrival,” Dr Leong said.
He added that the best way to do so would be with a vaccine booster to increase antibody count.
Prof Tambyah said that the variant should not be a grave concern because none of the mutations to emerge from the original virus in Wuhan, China has been “more deadly or virulent” so far.
“Even the Delta variant is much more transmissible but overall not more virulent (and) that is what most viruses do,” he said. “They become more transmissible but less deadly…. There is no reason to believe that this virus will be any different.”
He added that very much like what is occurring now, most people should just test themselves at home and should they test positive, rest at home until they are recovered.
“The best way to respond to this variant is not to try to go for a zero-Nu-variant (stance) but continue to live with the virus as we have been doing for the last month and a half.” — TODAY
