The director of the Centers for Disease Control and Prevention toured a COVID-19 testing laboratory at Princeton University on Thursday.

Dr. Rochelle Walensky said the United States is seeing historically low numbers of COVID cases and encouraged Americans to get booster shots.

“We know that that primary series does give you some protection against hospitalization – about 50%. That booster rises right up to 90%,” Walensky said.

The Princeton University lab has processed over 700,000 COVID tests for the school’s COVID-19 testing program since November 2020. With new variants of the virus on the rise, testing and funding continue to be a priority.

“We need to have our testing, our vaccines, our boosters, our therapeutics in place, brought ready to deliver to the American people,” Walensky said.

The possibility of a second booster shot and the BA.2 variant were hot topics during the director’s visit. The CDC says it has been tracking BA.2 since January and it is likely to become the more dominant variant because it is more transmissible. But the agency says the variant does not lead to more disease than Omicron.

“We know with Omicron and even with BA.2 that you have about a 50% chance of staying out of the hospital if you’ve had your primary series. That increases to 90% if you’ve had your booster shot,” Walensky said.

Both Pfizer and Moderna have applied for second booster approval. Walensky said the Food & Drug Administration and the CDC will review the data before making any recommendation for a second shot.

The director said that more people should get the first booster – especially in New Jersey.

“Only about 30% of people who’ve been eligible have gotten their first boost,” she said.

Walensky said the CDC is still evaluating the requirement to wear masks on planes, trains and buses.