Vaccines and masks will be the United States' first line of defense against the new omicron variant, not lockdowns or border closures, President Joe Biden told the nation Monday.

"If people are vaccinated and wear their mask, there's no need for lockdowns," Biden said, noting that vaccinated people who have gotten a booster shot are expected to have the best available protection against the omicron strain.

Biden said the United States placed travel restrictions on southern African countries to give Americans more time to get vaccinated and boosted against COVID-19, but he added that more travel bans are not planned at this time. "The degree of the spread impacts on whether or not there's a need for any travel restriction," Biden said. "I don't anticipate that at this point."

The Biden administration is working with vaccine makers Pfizer, Moderna, and Johnson & Johnson to prepare contingency plans for updated vaccines or boosters if they are needed to block the omicron variant, Biden said. The White House plans to issue later this week a "detailed strategy outlining how we're going to fight COVID this winter, not with shutdowns or lockdowns, but with more widespread vaccinations, boosters, testing and more," Biden said.

News reports out of South Africa noted that COVID-19 cases from omicron have resulted in mostly mild symptoms. "So far they have mostly been very mild cases, with patients having flu-like symptoms: dry coughs, fever, night sweats, a lot of body pains," Unben Pillay, M.D., a general practitioner in South Africa's Gauteng province, said during an online media briefing.

"Most of these patients have been treated at home," said Pillay, the Associated Press reported. "Vaccinated people tend to do much better. We have not seen a vast increase in hospitalizations, but this is still early days. Hospitalizations often come several days after a rise in confirmed cases."