CALL TO STEP UP VIRUS GENOME SEQUENCING
We are doing very little compared with others to track new variants to break chain, say experts
HEALTH experts have called for increased genomic surveillance and epidemiological analysis to track the SARS-CoV-2 variants and break the chain of Covid-19 transmission in the country.
Epidemiologist Datuk Dr Awang Bulgiba Awang Mahmud said Malaysia was doing “very little” of these compared with countries like the United Kingdom (UK), Denmark and Iceland.
“The UK, for example, sequences 7.5 per cent of samples from all their infected cases, so the number of genome sequences they have done is staggering.
“They follow this up with epidemiological and lab analysis so they can state whether a new variant is a variant of concern, which has phylogenetic properties different from existing variants.
“The Covid-19 Genomics UK Consortium regularly publishes reports on their analyses to inform policy. In comparison, Malaysia does very little genomic surveillance, which is why we do not even know whether the newer variants have been here for some time,” he told the New Straits Times when asked to comment on the B.1.351 strain of the Covid-19 virus, first reported in the UK and South Africa last December, and now being transmitted locally.
Dr Awang Bulgiba called for the government to randomly sequence some of the viruses found in infected persons in the country, particularly from large clusters, to see if such newer variants were now found here.
The ministry, he said, should then analyse the characteristics of patients carrying this particular variant and see if they were different from patients with other variants.
“For example, does the variant cause a more severe form of Covid-19 or cause a longer infectious period?
“Only then we can say for sure if we need to modify our prevention and treatment strategies or whether the current strategies are sufficient.”
He said the ministry should request universities to help out as many had the capability to perform genome sequencing and analyse these patterns.
Malaysia, he said, should also test whether the antibodies produced in response to the vaccines used in the country would work against these new variants. This had to be done continuously as viruses mutate all the time.
“Recent reports (not peer-reviewed yet) suggest that the number of antibodies in response to the B.1.351 variant through immunisation by vaccines currently in use is less than that for other variants, but they also suggest that the current vaccines may still work via other mechanisms.
“The current vaccines used in the UK work against the B.1.1.7 and a recent report (not peer-reviewed yet) suggest that the Pfizer vaccine works against the B.1.351 to some extent, despite the presence of the N484K mutation, which is said to enable the virus to evade antibodies.
“Of course, antibodies are not the only line of defence the body has against the SARSCoV2. There are the B cells and T cells which help the body fight against these infections too.”
He said while the UK (B.1.1.7), South Africa (B1.351) and Brazil (P.1) variants were said to be more infectious, the estimates on their infectiousness varied between places.
“There have been reported cases of the B.1.1.7 variant and now the B.1.351 variant in Malaysia, but since we did not perform much genome sequencing, we cannot say whether variants other than these are already present.”
The Science, Technology and Innovation Ministry’s Independent Covid-19 Vaccination Advisory Committee (ICVAC) head said the committee had recommended to the government to establish a voluntary Covid-19 Vaccination Registry.
A total of 50,000 subjects would need to be recruited into this registry and followed up for two years, he said.
“They will be followed up to evaluate how long the immunity from the vaccination will last, so testing for B and T cells (CD4, CD8) needs to be done in addition to antibody levels.
“Rare side effects of the vaccination like Type I interferon response can also be monitored in this way. We hope that the government will heed this call as these B and T cells are crucial for long-term immunity.”
He said a recent report (yet to be peerreviewed) suggested that T cell immunity might still work against the newer virus variants, even when the level of circulating antibodies were not as high as needed.
“If we do all these modes of surveillance and combine it with increased genome sequencing, we can also check whether the immunity that we have acquired through vaccination works against the newer variants.”
Meanwhile, Manipal University College Malaysia’s Professor of Community and Occupational Medicine Dr G. Jayakumar said the B.1.351 variant was more virulent.
Recent clinical trials conducted by vaccine manufacturers like Pfizer, Novavax and Johnson & Johnson, he said, showed that their new vaccines were less effective against the variant.
“The silver lining is vaccines can be redesigned and tweaked to be a better match for the new variants in a matter of months.” Jayakumar also said more genome sequencing analysis had to be conducted to identify the Covid-19 virus variants.
“Time will tell if we have managed to contain the spread of the virus. The principles of curbing the spread of this strain remains by practising basic public health measures.
“It is a concern if we let our guard down by not abiding by the standard operating procedures (SOP), especially with the forthcoming Hari Raya celebrations.
“We experienced a new wave last year after the Sabah elections. India is another example, where cases are rising after an earlier dip. We are still in the initial phase of vaccination.”
He added that the Covid-19 vaccination registration should be ramped up and more effort needs to be taken to overcome the myths and unsubstantiated rumours in social media regarding the vaccines.