This increased sensitivity applies to both the future mother and the newborn. “Maternal immunization”, or vaccination during pregnancy, is a fairly recent strategy that protects both the woman and the fetus/future newborn from several preventable infections.
Vaccinations against influenza, tetanus, pertussis (dTpa) and diphtheria are currently recommended during pregnancy. The inactivated polio vaccine (IPV), although not routinely recommended, can be administered to pregnant women at high risk of exposure to poliovirus (e.g. when traveling to endemic countries).
For more information, read the FAQ in the section titled “WHICH VACCINES SHOULD I GET WHILE PREGNANT? Current maternal immunization”.