Catherine Smallwood, WHO's senior emergency officer for Europe, said that travel measures should be implemented in a non-discriminatory manner.

“That's not to say that we recommend testing of passengers coming from the US at this stage. Countries need to look at the evidence base for pre-departure testing. When it comes to other measures things like mask wearing on long-haul flights, WHO’s recommendation is that passengers should opt to wear a mask in high-risk settings, such as long-haul flights,” Smallwood said a virtual media briefing.

“And this should be a recommendation issued to passengers arriving from anywhere where there's widespread covid-19 transmission,” she added.

The XBB family of variants emerged a few months ago and caught virologists’ attention because it contains more mutations to evade immunity than any other variant.

The XBB.1.5 variant has a mutation virologists believe is helping the virus better bind to cells and thus be more transmissible.

The XBB.1.5 virus has quickly become a higher percentage of total COVID cases in the United States. (ILKHA)