Singapore — With the emergence of a new, more contagious Covid-19 variant, a health expert has disclosed that it might be important to increase the percentage of vaccinations of the population from the stated 80 per cent to 90 per cent or even higher.
Professor Teo Yik Ying said on Thursday (Dec 24) to The Straits Times during its daily online talk show The Big Story that the increase in vaccinations “is the only way we can continue to ensure that the community as a whole is protected”.
Prof Teo is the dean of the Saw Swee Hock School of Public Health at the National University of Singapore.
The Ministry of Health’s (MOH) chief health scientist, Professor Tan Chorh Chuan, said on Dec 16 that at least 80 per cent of Singapore’s population would need to be vaccinated to achieve herd community against the virus.
“Where most of a population have immunity to the virus, this ‘herd immunity’ indirectly reduces the risk of infection for those who are not immune to it, thereby limiting infection clusters,” said Prof Tan.
“The estimates for herd immunity vary generally around 60 to 70 per cent of the population, but a vaccine coverage of at least 80 per cent would be prudent.”
It is assumed that if a Covid-19 vaccine’s efficacy is around 90 per cent, an 80 per cent population vaccination would entail about 72 per cent of the population would become protected from the virus, he noted.
Emergence of the B117 strain and new variants
Recent news has highlighted the emergence of a new B117 strain of Covid-19, circulating in Britain towards the end of November. The strain is reported to be more contagious, although there is a lack of evidence showing it is more severe or lethal.
The new variant has to date pushed more than 40 countries, including Singapore, to ban arrivals from the United Kingdom.
Meanwhile, the World Health Organization announced on Tuesday (Dec 22) that the B117 variant had been identified in several countries, such as Australia, Denmark, Iceland, Italy and the Netherlands. There is also an unrelated variant identified in South Africa sharing one of the genetic mutations of the Covid-19 strain, according to a report the same day on scmp.com (South China Morning Post).
Singapore reported its first B117 case on Wednesday (Dec 23), a 17-year-old female Singaporean. She had been studying in the UK from August 2020 and returned on Dec 6.
The MOH announced that all her close contacts were placed on quarantine and had tested negative for Covid-19 infection at the end of their quarantine period. “As she had been isolated upon arrival in Singapore, we were able to ringfence this case so that there was no further transmission arising from her,” it added.
Vaccine still effective against new strains
Meanwhile, health experts, including Prof Teo, have indicated that the new variants or strains would not affect the effectiveness of vaccines.
However, a better understanding of the new strains is needed before determining the likely impact and making appropriate policy decisions.
“Governments are concerned (about the new strains) because of the impact that they have in managing the spread of Covid-19 in the community, and also any potential impact on vaccine effectiveness and quality control measures,” said Prof Teo.
“But for individuals like you and me, as long as we continue to diligently practise the necessary safe management measures, there is no need to be overly concerned with these new mutations,” he added. /TISG
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