Which vaccine is contraindicated during pregnancy?

During pregnancy, certain vaccines are contraindicated due to the potential risk they may pose to the developing fetus. Live attenuated vaccines, such as the measles, mumps, and rubella (MMR) vaccine, are not recommended for pregnant individuals. This is primarily because these vaccines contain a weakened form of the virus that, while typically safe for healthy individuals, could potentially lead to an infection that poses risks to the fetus.

In contrast, the influenza vaccine is generally safe during pregnancy as it helps protect both the mother and the baby from flu complications. The tetanus-diphtheria vaccine is also recommended, especially during the third trimester, to protect the newborn from pertussis. Likewise, the hepatitis B vaccine is considered safe and is encouraged if the pregnant person is at risk for the virus. In summary, the live attenuated MMR vaccine is distinct in its contraindication due to the nature of live viruses it contains, making it unsuitable for administration during pregnancy to prevent possible risks to fetal development.