More than half the world? We talking population or countries?
Seems like an awful lot, but I have no idea about vaccines in other countries. Also do you only need 1 vaccine against measles once in your life or does it require a 2nd one later in life?
More than half the world? We talking population or countries?
Seems like an awful lot, but I have no idea about vaccines in other countries. Also do you only need 1 vaccine against measles once in your life or does it require a 2nd one later in life?