KUALA LUMPUR: Malaysia may need to consider sequencing the genome of SARS-CoV2 isolated from Covid-19 patients in the wake of new and more infectious variants of the virus.
Epidemiologist Professor Datuk Dr Awang Bulgiba Awang Mahmud said this following reports on three mutated Covid-19 coronavirus variants recently detected in the United Kingdom (UK), South Africa and Brazil.
While the prevalence of these variants in Malaysia was not certain as there was not much effort to sequence the virus’ genome, he said he would not be surprised if they were already here.
“There has been one imported case of this variant (B.1.1.7 from the UK) reported in Malaysia, but since we have not done much genome sequencing, we cannot say whether the variant is already here before that imported case was detected,” he told the New Straits Times.
Therefore, he said, the authorities should randomly sequence some of the viruses found in patients, particularly from large clusters, to determine if such variants were in the country.
Health authorities, he said, should analyse the characteristics of patients carrying a particular variant and determine if they were different from patients with other variants.
“For example, does the variant cause a more severe form of infection or cause a longer infectious period?
“Only then we are able to know for sure if we need to modify our prevention and treatment strategies, or if the current strategies are sufficient in handling this.
“Currently, there is very limited sequencing of Covid-19 viruses in Malaysia and hardly any studies done on how any new variant can affect infections.”
Dr Awang Bulgiba said the Health Ministry should request the help of universities as they had the capability to perform genome sequencing and analysis.
“Malaysia should also test in vitro whether the antibodies produced in response to the vaccines we are going to use will work against the new variants. This needs to be done continuously as viruses mutate all the time.”
As for the quarantine period for individuals suspected to be infected, Dr Awang Bulgiba said a 14-day home isolation period, rather than 10 days, could be imposed as a cautionary measure.
He said the most recent variant in the UK from the B.1.1.7 lineage would have a set of more than 20 changes or mutations.
“The two most significant ones (of the UK variant) are the N501Y, which affects the spike protein, hence potentially the virus’ infectiousness, and the ’69-70 deletion’, whose effect is unclear at the moment.”
The South Africa variant, he said, was called 501Y.V2 (also known as the B.1.351 lineage) and the one from Brazil was called the P.1 lineage, which was causing concern in other countries as well.
“The South Africa variant also has multiple mutations, including N501Y and E484K, both of which affect the spike protein and might have a bearing on infectiousness.
“The Brazil variant shares the same three mutations as the South Africa variants (K417N/T, E484K, N501Y) and one mutation found in the UK variant (N501Y).
“The set of mutations/deletions shared between P.1, B.1.1.7 and the 501Y.V2 variants appeared to have risen independently.”
Dr Awang Bulgiba, who is also the Science, Technology and Innovation Ministry’s head of the Independent Covid-19 Vaccination Advisory Committee, said while the risk of transmission and the infectious period of the new variants were still being studied, the three were believed to be more pathogenic, although their estimated infectiousness might vary.
He said there was always a danger of being unable to achieve herd immunity due to the rise of new variants not covered by vaccines.
“We need to monitor developments in other countries and the responses of vaccine makers. I am sure these companies are closely studying the new variants.
“The South African variant has been linked to reduced antibody response, meaning our bodies may be less able to fight it off, but this has not yet been properly established.
“Pharmaceutical companies with vaccines undergoing trials or have already been approved are closely studying these new variants to see if there is a need to modify vaccines to address them.”
Epidemiology and biostatistics expert Associate Professor Dr Malina Osman said the new strain could potentially produce positive cases in a much shorter period, which could overstretch the healthcare system.
“The new variants are found to have a higher transmissibility rate and are more infectious.
“However, there is no conclusive data as to whether these variants would cause severe infection. The new strains could potentially produce more cases in a shorter duration, which is a cause for concern for hospital management.”
On the effect of mutations on the existing Covid-19 vaccines being developed, she said to date there had been no evidence to show any real issues related to the (harmful effects of the) vaccine and, as such, it would not affect the government’s vaccination programme.