https://www.cdc.gov/vaccines/vpd/should-not-vacc.html https://www.cdc.gov/vaccines/vpd/should-not-vacc.html It varies by vaccine, but allergies, health conditi

https://www.cdc.gov/vaccines/vpd/should-not-vacc.html https://www.cdc.gov/vaccines/vpd/should-not-vacc.html It varies by vaccine, but allergies, health conditions, and age are all factors. Some people also practice religions that forbid them.