The Centers for Disease Control and Prevention on Thursday endorsed updated COVID-19 boosters, opening the way for a fall vaccination campaign that could blunt a winter surge if enough Americans roll up their sleeves. The new boosters targeting today's most common omicron strains should begin arriving in pharmacies and clinics within days. They're combination or "bivalent" shots that contain half the original vaccine that's been used since December 2020 and half protection against today's dominant omicron versions, BA.4 and BA.5. It's the first update to COVID-19 vaccines ever cleared by the Food and Drug Administration. Updated shots made by Pfizer and its partner BioNTech are authorized for anyone 12 and older, and rival Moderna's version is for adults. They're to be used as a booster for anyone who's already had their primary vaccination series -- using shots from any U.S.-cleared company -- and regardless of how many boosters they've already gotten. The FDA set the minimum wait time at two months. But advisers to the Centers for Disease Control and Prevention said it's better to wait longer. Some advise at least three months, another said someone who's not at high risk might wait as long as six months. It's still important to get vaccinated even if you've already been infected -- but timing matters here, too. The CDC has long told people to defer vaccination until they've recovered but also that people may consider waiting for three months after recovering to get a vaccination. And several CDC advisers say waiting the three months is important, both for potentially more benefit from the shot and to reduce chances of a rare side effect, heart inflammation, that sometimes affects teen boys and young men.