- Joined
- Jun 24, 2019
Oral Polio Vaccine is safe and effective to an extent, but the live virus it contains has a bad habit of mutating into something that can cause disease and spread, so it's not used or approved in the US anymore. It's a big reason why Polio still exists outside of labs. The inactivated vaccine does not provide sterilizing immunity, but also can't spread Polio.