People age 50 and up are eligible for a second booster dose of COVID-19 vaccine at least four months after their first, the Food and Drug Administration said. “Based on an analysis of emerging data, a second booster dose of either the Pfizer-BioNTech or Moderna COVID-19 vaccine could help increase protection levels for these higher-risk individuals,” Dr. Peter Marks, who directs the FDA’s Center for Biologics Evaluation and Research, said in a statement. The Centers for Disease Control and Prevention has to sign off on the booster before it becomes available. It's not clear how soon that may happen. A second booster dose of an improves protection against severe COVID-19 and is not associated with new safety concerns, the FDA said. But when and whether individuals gets one remains a personal decision that should be based on age, health status and the course of the pandemic, experts said. "Obviously, the older you are, the higher the risk; and the more underlying conditions the higher the risk," said Dr. Tom Frieden, the former director of the Centers for Disease Control and Prevention, who now heads Resolve to Save Lives, an initiative to prevent epidemics and cardiovascular disease. But Frieden said if he had a healthy 55-year-old patient who was already vaccinated and boosted, he'd be less concerned about getting that person another shot. "If you want to get one, fine. If you don't, it's really up to you," Frieden said he'd tell that patient.