Experts allay fears of threat to Vietnam from UK coronavirus mutant

On Jan 2 Vietnam reported the first case of the variant.

The carrier was a 44-year-old Vietnamese woman who came with a group of 305 passengers from Britain and landed in the southern Can Tho on December 22.

They were quarantined in Can Tho, the nearby provinces of Vinh Long and Tra Vinh and HCMC.

"I am not particularly concerned for Vietnam, since the country has very well established surveillance, contact tracing and border control measures," Professor Yik Ying Teo, dean of the Saw Swee Hock School of Public Health, National University of Singapore, said when asked about the possible threat Vietnam faces.

"So the risk of this variant subsequently being transmitted to the community is actually extremely low."

Workers at Linh Trung Export Processing Zone in HCMC's Thu Duc District line up for Covid-19 test in April 2020. Photo by VnExpress/Quynh Tran.

Underscoring the similarities between Vietnam and New Zealand, Professor Michael Baker of the public health faculty at the University of Otago in New Zealand said both countries have elimination strategies and both are largely succeeding in containing Covid-19 resulting in low case numbers and deaths.

In a recent report Baker and his colleagues listed Vietnam as one of the countries in Asia that seems to have elimination as the dominant strategy.

They concluded that elimination could be the optimal response strategy for Covid-19 and other emerging pandemics. For successful elimination they listed the following conditions: informed input from scientists, political commitment to take decisive action, sufficient public health infrastructure to deliver the necessary interventions, public engagement and trust in the measures being taken, and a social safety net to support vulnerable populations.

Preparation for long-term effort

Hassan Vally, associate professor in public health, La Trobe University, Australia, said it is important to understand the new variant, while potentially being more transmissible, should not change the approach of any country to controlling Covid-19.

There is no evidence that this variant is different in any other way, and so all of the same measures to prevent transmission of the virus should continue, he added.

Associate Professor Alex Cook of the Saw Swee Hock School of Public Health said the evidence from the U.K. is that the new virus’s infectivity is potentially 50 percent or higher.

This means existing measures might not be sufficient to keep its R-value to 1 or less, which would lead to epidemic growth, he said.

Countries like Vietnam, Thailand and Singapore that have kept transmission more or less under control might therefore need to step up measures if the variant is found locally, he warned.

But he too expressed confidence, despite a possible risk of spillover from travelers to the general community, that Vietnamese authorities could contain it with existing measures.

The experts said there is no need for more than 14 days of quarantine.

Baker said there is no evidence that the incubation period is longer than usual for the new variant of the virus. He did not think additional tracking would be needed once someone has completed the normal quarantine.

But given that the variant is more infectious, it would be important to maintain high standards of infection control during quarantine, he said.

While Vietnam’s current border controls would of course also keep it out, it would be important to consider additional measures to reduce the number of imported cases since the variant is more infectious, he said.

"These measures could include pre-departure testing and potentially a brief period of quarantine before travel."

According to Professor Hajo Zeeb of the Leibniz Institute for Prevention Research and Epidemiology in Germany, it is certainly a situation where strict containment is important given the absence of immunity in Vietnam.

While the new strain is more transmissible, it does not seem to cause a more severe manifestation of the disease, he said.

This higher transmissibility rate is a problem when it comes to control, but there are no special measures beyond those known to work so far (distance, hygiene, contact reduction, etc), and the vaccines are expected to work also for this strain, he said.

Teo said though the 14-day quarantine does have the risk of missing some infected travelers, it is about balancing risk management with practicality.

A longer period of quarantine would certainly be safer, but causes greater inconvenience to travelers, and so individual countries have to decide on the balance, he said.

Hong Kong has opted for a longer quarantine, but there are also many countries that stick to the 14-day regime even for travelers from the U.K., he pointed out.

Dr Julian Tang of the University of Leicester in the U.K. said while the new variant does not seem to be causing a more severe disease people know that a proportion of those infected would need hospitalization and some would die.

For that reason, Vietnam needs to enhance all measures to reduce the spread of this highly transmissible strain to avoid overwhelming its healthcare system, he said.

The country could use the S-gene dropout PCR signal if its screening targets multiple virus genes, including the S gene, which fails to be detected in the variant, he said.

If Vietnam's PCR test is different from the TaqPath test, it might need to rely on sequencing (which is slower) to detect this U.K. variant, though scientists could possibly design a new specific PCR assay to detect this variant also, he said.

Clinically, Tang and his colleagues are not seeing much difference between the new and the old virus strains and do not think the effectiveness of existing vaccines would be affected much.

He said existing social distancing measures, masking and other interventions need to be more strictly observed to reduce the spread of this virus.

Vietnamese scientists could also check the effectiveness of their vaccine in neutralizing the new U.K. variant -- and might need to do this for the new South African variant, which is likely to come to Vietnam too -- in the near future, he said.

Teo said the world is aware of these variants only because the two countries have been putting in efforts to do a lot more genetic sequencing of the coronavirus.

"It could be there are other variants out there as well but are presently undetected."