WASHINGTON (AP) – Johnson & Johnson has asked U.S. regulators to allow booster shots of its COVID-19 vaccine as the U.S. government moves toward shoring up protection in more vaccinated Americans. J&J said Tuesday it filed data with the Food and Drug Administration on giving a booster dose between two to six months after vaccination. The U.S. government last month authorized booster doses of Pfizer’s vaccine in vulnerable groups. A panel of FDA advisers meets next week to consider boosters for both J&J and Moderna vaccines. It’s part of a sweeping effort by the Biden administration to boost protection amid the delta variant and potential waning of vaccine strength.