RELATED: Pfizer Executive Says This Is Who Will Get COVID Booster Shots First. Peter Marks, MD, director of the FDA’s Center for Biologics Evaluation and Research, said that while both the current versions of the Pfizer and Moderna vaccines are highly effective at preventing COVID and protecting against circulating variants, booster shots will still be necessary—and they may be administered sooner rather than later. “You know, it would be nice if it’ll turn out that it’ll be a year before anyone might need a booster,” Marks said on May 18 during a virtual press conference with high school and middle school journalists, as reported by CNBC. However, Marks did note that the timing is something experts are not yet certain about. During a May 11 episode of the podcast COVID: What Comes Next, public health expert Ashish Jha, MD, dean of the Brown University School of Public Health, said that he expected it would be “at least” a year before vaccinated individuals need COVID booster shots. “We still don’t know,” Marks explained. “It could be more, it could be a little less but … this is just something we’re going to have to figure out as we go.” RELATED: For more up-to-date information, sign up for our daily newsletter. The mystery lies in the fact that U.S. regulators and scientists still don’t know how far immunity levels need to drop before those who have been vaccinated become vulnerable to the virus again, explained the FDA’s Acting Commissioner Janet Woodcock, MD, according to CNBC. However, BioNTech CEO Ugur Sahin, MD, told the outlet on April 30 that researchers are seeing a decline in antibody responses against the virus eight months after vaccination. “If we provide a boost we could really amplify the antibody response even above the levels that we had at the beginning and that could give us real comfort for protection for at least 12 months, maybe 18 months,” Sahin said. Rochelle Walensky, MD, the director for the Centers for Disease Control and Prevention (CDC), also recently told CNBC that the U.S. government is planning for the potential need for COVID booster shots, “just in case.” “Right now, if you have two doses of the mRNA vaccines, you are protected,” Walensky said on May 11 during CNBC’s Healthy Returns Summit. “What we’re talking about is thinking ahead. What happens if in a year from now or 18 months from now your immunity wanes? That’s really our job is to hope for the best and plan for what might happen if we need further boosters in the future, the way we get flu vaccine boosters every year.“ae0fcc31ae342fd3a1346ebb1f342fcb The good news is, boosters will be of no cost to you. While speaking to the Senate Health Committee on May 11, David Kessler, MD, chief science officer for the White House’s COVID-19 Response Team, said the next round of COVID shots will be free to people in the U.S., just like the initial vaccinations were. “We are planning, and I underscore the word planning, to have booster doses available if necessary for the American people,” Kessler said, according to CNBC. “We do have the funds to purchase the next round and to assure if there are boosters that they are free just as the last round.” RELATED: Dr. Fauci Says These 2 Things Determine If You Need a COVID Booster.