Among the 29% of U.S. voters who are unvaccinated, 83% say they do not plan to get the lifesaving shots, the survey shows. A frustrated Biden on Thursday outlined a host of new vaccine and testing mandates for federal workers and contractors as well as health-care and private company employees…

Of the unvaccinated respondents, 84% said their decision against immunization wouldn’t change if the vaccines had no side effects and 87% said they still wouldn’t get the shots if their employer mandated them. Just 5% and 4% of respondents, respectively, said those things would make them “much more likely” to change their minds, the survey shows. Pressure from family members made little difference, with just 2% saying that would make them much more likely to get the shots.

Growing vaccine hesitancy could make it difficult to reach the up to 90% vaccination rate that some health officials have suggested is necessary to achieve nationwide herd immunity to Covid.