This may include adverts from us and 3rd parties based on our understanding. Non US citizens who have recently been in any of the eight countries will be allowed to board US bound flights from December 31 at 12.01 am East Coast time. The Centers for Disease Control and Prevention spokesman Kevin Munoz said on Twitter that the restrictions were a precautionary measure, and it was now known that the existing vaccines work against Omicron. He said that the restrictions gave us time to understand Omicron and we know our existing vaccines work against Omicron, esp boosted. The travel restrictions were recommended by US public health officials earlier in the day. The travel bans wouldn't have a major impact on US cases, since transmission would be across the country, they argued. Officials are now confident that a specific Omicron-specific vaccine would not be necessary. There is now available data showing existing vaccines and booster shots are highly effective against Omicron. READ MORE: Dog looks after a newborn baby abandoned in the field like one of her own puppies.