Omicron variant more easily transmissible, but too early to tell if new restrictions necessary: Experts

SINGAPORE: It is “too early” to tell if additional measures are required to deal with the Omicron COVID-19 variant in Singapore, but if needed, restrictions on travel and social gatherings would be most effective, experts said.

Associate Professor Natasha Howard from the Saw Swee Hock School of Public Health at the National University of Singapore noted that Omicron appears to be “much more easily transmissible” than the dominant Delta variant.

While this could mean a “significant increase" in cases, there is no indication that the Omicron variant raises the risk of severe illness or death, she said.

“We don’t yet have enough information about the Omicron COVID-19 variant to know how great a risk it poses and whether additional precautions will be necessary,” she said.

“We are in the early days and learning more daily about this new variant of concern, so (we) must maintain existing measures until new evidence indicates whether increased restrictions are warranted.”

Singapore's COVID-19 multi-ministry task force said on Tuesday (Nov 30) that it is a “matter of time” before Omicron cases emerge here. As part of tightened measures, the country has enhanced its testing protocols for all travellers. No new vaccinated travel lanes will be opened, other than those announced earlier.

Prime Minister Lee Hsien Loong earlier said that Singapore could be forced to take "a few steps back" before taking more steps forward, as he spoke about the new variant.

Associate Professor Luo Dahai​, from Lee Kong Chian School of Medicine ​at Nanyang Technological University, said many questions about the new variant have not been answered.

“It is difficult to determine what levels of restriction would be appropriate and effective in protecting Singapore and Singaporeans,” he said.

RESTRICTIONS THAT COULD HELP

The experts said Omicron is likely to emerge in Singapore in days. Given that it is unclear how effective existing vaccines are against the variant, restrictions that help minimise transmission would be most effective, Assoc Prof Howard said.

“These include working from home as default, minimising the size and frequency of social gatherings – especially indoors, continuing mask-wearing and reinforcing infection prevention protocols at border entry points,” she said.

Other measures include on-arrival polymerase chain reaction (PCR) tests and stay-home notices until receipt of a negative result for inbound travellers.

Infectious diseases physician Ling Li Min noted that the effectiveness of vaccines is a concern.

“Given that it has many mutations in the same regions of the spike protein, it would be able to evade some of the antibodies that people have acquired either from vaccines or from COVID-19 infections,” said Dr Ling, who practises at Rophi Clinic at Gleneagles Hospital.

Some monoclonal antibody treatments may not work against Omicron, she added.

Any restrictive measures implemented would include a series of measures from household visits, social activities, dining in at eateries and travelling in and out of Singapore.

Travel restrictions would reduce the risk of exposure to the virus, especially for international travel, Assoc Prof Luo said.

DETERMINING THE RISK

But National University Hospital's Professor Dale Fisher said border closures would only slow down the introduction of the variant here.

“I think it's inevitable. We can’t close the borders every time there is a new variant of concern. Any measures introduced should align with our COVID resilience strategy,” said the senior consultant at the hospital’s division of infectious disease.

Assoc Prof Howard echoed the view. Closing borders now that it has already crossed into multiple countries may not be “particularly useful”, she said.

“It is most important to find out as quickly as possible what risks this new variant of concern poses, how vaccines may need to be updated, and whether our existing public health responses need to be revised,” she said. 

Prof Fisher, who is also chair of the national infection prevention and control committee at the Ministry of Health, noted that most restrictions come with some social and economic impact.

“We need to act on the science and what is known rather than fear. It is not sustainable to bounce in and out of the restrictions every time we find a new variant of concern,” he said.

He also said that given Singapore still has many restrictions in place – more than most of the rest of the world – it is “quite simple” to pause the easing of restrictions without going backwards.

WORST-CASE SCENARIO

The most important parameter in deciding restrictions will be the severity of the Omicron variant, Prof Fisher said. The information on the outcomes of those vaccinated and not vaccinated who contract Omicron needs to be stratified by age and comorbidities, he said.

“If we find that the outcomes are similar or worse than Delta and that these outcomes occur irrespective of vaccine status then we most certainly have a problem,” he said.

In the worst-case scenario involving the Omicron variant being more severe, it would “really require extreme measures given the amount of transmission currently in place”.

It would be very difficult to reintroduce contact tracing, quarantine and supervised isolation of cases without a drastic reduction in current COVID-19 numbers, he said. However, based on the information so far, the speculation is that it could be milder, he said.

“A non-severe yet very transmissible variant that replaces Delta would likely be a good thing. It’s just too early to tell yet,” he said, adding that more information on the variant will emerge in the next couple of weeks.

“A pause in easing and some planning for a worst-case scenario while we await the outcomes' data is the line we should now be walking.”

Amid the emergence of Omicron and changing rules on international travel, the experts suggested anticipating these changes or avoiding international travel if possible.

However, Assoc Prof Howard said there is no reason to panic given that Singapore’s “tried and true” public health responses continue to be effective during each stage of the pandemic.

She urged people to get vaccinated and get their booster jabs when they are eligible.

“While vaccines may be less effective against Omicron, evidence thus far suggests they are still beneficial. Do keep wearing your mask, safe distancing and minimising large gatherings,” she said.