It takes time after vaccination for immunity to the virus to build up, and no vaccine is 100% effective. Plus, scientists don't yet know if the vaccine stops viral spread. Here's what's known so far.
Copyright 2021 NPR
It takes time after vaccination for immunity to the virus to build up, and no vaccine is 100% effective. Plus, scientists don't yet know if the vaccine stops viral spread. Here's what's known so far.
Copyright 2021 NPR