The Centers for Disease Control and Prevention said Friday that the protection against COVID-19 bestowed by vaccine booster shots takes a nosedive after four months. The new data, taken from over 240,000 visits to emergency rooms for COVID treatment from August 2021 to January 2022, indicates that many Americans, particularly those at high risk for coronavirus infection, may need additional shots to shield themselves from hospitalization. Researchers from Israel and the U.K., which began vaccination campaigns earlier than the U.S., had come to similar conclusions. According to The New York Times, some research has shown the falling efficacy of the vaccine is more pronounced in adults over 65 than in younger people. Dr. Anthony Fauci said earlier this week, “There may be the need for yet again another boost—in this case, a fourth-dose boost for an individual receiving the mRNA—that could be based on age, as well as underlying conditions.”