Prof Mark Woolhouse said the new principles had arrived too behind schedule to have a material effect to an expected rush of the Omicron variation in the UK.
The progressions incorporate pre-flight tests for individuals showing up in the UK and Nigeria going on the movement red rundown.
No 10 said the progressions were because of an ascent in movement connected Omicron cases.
From 04:00 GMT on Tuesday everybody matured 12 and over should step through an exam a limit of 48 hours prior to leaving.
Under the changes, travelers will be needed to show verification of a negative PCR or sidelong stream test taken no sooner than 48 hours before takeoff.
Nigeria will likewise be added to the movement red rundown of nations from Monday, which implies UK or Irish nationals, or UK occupants getting back from the nation should isolate in an inn for 10 days.
Be that as it may, the most recent changes have been portrayed by the movement business as a sledge blow, with the Business Travel Association cautioning occupations would be crushed.
Agent Prime Minister Dominic Raab acknowledged the furthest down the line measures may agitate or disturb certain individuals, however demanded it was appropriate for priests to make gradual stride right on time to stay away from greater interruption to travel and the economy.
Prof Mark Woolhouse, an individual from the public authority’s Scientific Pandemic Influenza Group on Modeling (Spi-M), told the BBC’s Andrew Marr that while imported instances of the Omicron variation were significant, local area transmission of Omicron would be the driver of a next wave.
He added the quantities of UK Omicron cases were right now minuscule and he unequivocally speculated irrefutably the number was “more in the hundreds than the large numbers.
Be that as it may, he cautioned Omicron was spreading pretty quickly in the UK, and if latest things here and in South Africa proceeded in the coming many months, it could even supplant the Delta variation all over the planet.