Factors that increase the risk of polio infection include pregnancy, the very old and the very young, immune deficiency, and malnutrition. Although the virus can cross the maternal-fetal barrier during pregnancy, the fetus does not appear to be affected by either maternal infection or polio vaccination. Maternal antibodies also cross the placenta, providing passive immunity that protects the infant from polio infection during the first few months of life.
Factors that increase the risk of polio infection include pregnancy, the very old and the very young, immune deficiency, and malnutrition Although the virus can cross the maternal-fetal barrier during pregnancy, the fetus does not appear to be affected by either maternal infection or polio vaccination. Maternal antibodies also cross the placenta, providing passive immunity that protects the infant from polio infection during the first few months of life.