Live Attenuated versus Inactivated Vaccines

Compared to inactivated vaccines, live attenuated vaccines tend to have higher rates of adverse effects (particularly fever).¹³ Potentially, vaccines containing live attenuated viruses can also infect the fetus. Vaccines containing live attenuated viruses should only be administered to pregnant women if there is a high immediate risk of infection by a specific pathogen, e.g., a poliomyelitis epidemic. The same precaution applies to individuals with a compromised immune system (Box 2)