PHILADELPHIA (WPVI) -- The U.S. recorded its first confirmed case of the omicron variant Wednesday - in a vaccinated traveler who returned to California after a trip to South Africa. The person had not received a booster shot, according to health officials.
Dr. Anthony Fauci, the nation's top infectious disease expert, said Americans should focus on getting boosters to protect themselves against this new variant, based on experience with the delta variant.
"When you get a high enough level of an immune response, you get spillover protection even against a variant that that vaccine wasn't specifically directed at," said Fauci.
Officials say the patient has experienced mild symptoms and is recovering.
As omicron is being detected in more countries, U.S. officials are reportedly considering tightening the testing policy for international travelers, and might soon require anyone entering the U.S. by air to test negative the day before their flight, instead of three days before departing.
In Philadelphia, health officials said Wednesday that hospitals are filling up with non-COVID patients, and it's affecting children's hospitals, too.
"RSV, other kinds of illnesses not related to COVID. It's just that when hospitals are 100% full any increase can be a real problem," said Dr. Cheryl Bettigole, commissioner of the Philadelphia Department of Health. "We're not in crisis mode in Philly but we're trying to stay out of crisis mode."
Officials are recommending double masking in crowded public spaces and of course, vaccines.
At the Gloucester County vaccine site in Clayton, New Jersey, people walked up without appointments and got their booster shots on Wednesday.
"It got my attention and I'm sure everyone says the same thing, 'Oh no, another variant.' But from what I understand, that's what you can expect. There's going to be offspring," said Jim Cummings of Williamstown.
Experts say the more people who are vaccinated, the less opportunity the virus has to mutate.