As vaccine rollout continues, AP poll finds a third of adults still skeptical of COVID shots According to experts, 80% of the population needs a vaccination to get to herd immunity, and with many still reluctant to getting the shot, there is work to be done. By: Cole Johnson and last updated 2021-02-24 14:34:58-05 NASHVILLE, Tenn. (WTVF) â According to experts, 80% of the population needs a vaccination to get to herd immunity, and with many still reluctant to getting the shot, there is work to be done. A poll from The Associated Press says that a third of U.S. adults are still skeptical of getting the shot, and that within that third, 15% are certain they won't get the vaccine and 17% say probably not.