NEW YORK (AP) — About 1 in 3 Americans say they definitely or probably won’t get the COVID-19 vaccine. That’s according to a new poll that some experts say is discouraging news if the U.S. hopes to achieve herd immunity and vanquish the outbreak. The poll from The Associated Press-NORC Center for Public Affairs Research found that while 67% of Americans plan to get vaccinated or have already done so, 15% are certain they won’t and 17% say probably not. Many expressed doubts about the vaccine’s safety and effectiveness, even though few if any serious side effects have turned up more than a month and a half into the vaccination drive.