NEW YORK (AP) — Three studies released Friday offered more evidence that COVID-19 vaccines are standing up to the omicron variant, at least among people who received booster shots. They are the first large U.S. studies to look at vaccine protection against omicron, health officials said. Three shots of the Pfizer and Moderna vaccines were about 67% effective against omicron-related symptomatic disease compared with unvaccinated people. Two doses, however, offered no significant protection against omicron, the researchers found. “It really shows the important of getting a booster dose,” said the CDC’s Emma Accorsi, one of the study’s authors.