To fight Omicron XE, second booster may not be necessary, says virologist

GEORGE TOWN: A fourth dose of a Covid-19 vaccine - a second booster - might not be needed to guard against the new Omicron XE variant, says a virologist.

Dr Kumitaa Theva Das from Universiti Sains Malaysia said while the "extremely high transmissibility" of the XE variant meant it could become the dominant strain soon, she observed that its global spread is under tight control.

"Despite this variant being first discovered in January, there does not seem to be many reports of it globally. As such, it is possible there is a high level of protection from boosters and from natural immunity from earlier infections," she said.

"The only neighbouring country which has detected XE so far is Thailand, with one case over the weekend. The spread was brought under control due to quick detection and it did not affect us," added Dr Kumitaa.

Dr Kumitaa said an additional booster jab - a fourth dose - may most likely not be necessary as the regular standard operating procedures (SOPs) are already helping tremendously to contain the spread of Covid-19.

These SOP include physical distancing, being in well-ventilated places and practising good hygiene.

"Despite the anticipated transmissibility, we have yet to discover other important aspects about the new variant, such as its severity, whether it causes reinfection or if our current vaccines work against it," added Dr Kumitaa.

As for the types of masks which give the best protection against the variant, she said that the XE variant is currently not designated as a variant-under-monitoring by the World Health Organisation, unlike XD (which is a hybrid of Delta and Omicron).

"As such the N95, KN95 and KF94 masks previously recommended for Omicron should be sufficient for XE," she said.

Dr Kumitaa said the opening of international borders may not necessarily put the country at high risk, as was seen with Mu and Lambda.

"As long as we maintain a robust surveillance system, we can identify cases to enable timely treatment or isolation and stop the spread.

She said for instance, maintaining testing prior to flights and right after and checking a person's vaccination status would go a long way in protecting the global population.

Dr Kumitta said the United Kingdom was able to pick up on the variant quickly because of their robust surveillance system and according to the global database GISAID, the UK has submitted more than one million Omicron samples for genome sequencing.

"So, the quick identification of XE shows that a good public health system will keep the case numbers extremely small," she added.