Tetanus, which is now rare in the developed world, can cause severe illness around the time of delivery in pregnant women and is usually fatal when it occurs in the newborn infant. At the end of the 1980s, the World Health Organization (WHO) estimated that 6.5 cases of tetanus occurred for every 1,000 live infants born worldwide and called for its elimination. Tetanus is preventable by vaccination of mothers either before or during pregnancy because tetanus antibodies are transferred very efficiently from mother to fetus and prevent the newborn from acquiring the infection during non-sterile delivery. Tetanus vaccination also has been shown to be safe in pregnancy. Through an initiative of immunizing pregnant women against tetanus in the developing world, the WHO successfully reduced the number of countries where newborn tetanus affects greater than one infant per 1,000 born to 49 by 2005.
In the developed world, tetanus vaccination is recommended every 10 years after the primary childhood vaccination. Pregnant women who have not been vaccinated within the previous 10 years or whose status is not certain should be immunized, and this is most commonly administered in a combined vaccine with diphtheria toxoid (Td) vaccine. In 2006, a new vaccine containing tetanus, diphtheria toxoid and acellular pertussis (Tdap) was licensed for use in adolescents and adults. Current CDC recommendations are that this vaccine is preferred in women of child-bearing age who are not pregnant. It should also be administered after delivery to all women who have received their last dose of tetanus toxoid-containing vaccine two or more years previously.
Inactivated influenza (TIV) vaccine (the “flu shot”) is recommended for all women who will be pregnant during the influenza season (October through March). This recommendation is based on reports that pregnant women have significantly higher rates of severe illness and death than the remainder of the population and are likely to be in contact with children of school age who often infect them with influenza virus.
During the influenza pandemics of 1918 and 1957, influenza-related complications affected as many as 50 percent of women infected with the virus. Vaccination has the benefit of preventing illness in pregnancy but may also have the advantage of providing young infants (for whom no vaccine is available but who are likely to need admission to hospital if infected) with protective antibodies against influenza. During the 1950s and 1960s, TIV was administered to 2,291 pregnant women. No adverse effects from vaccination were seen when mothers and infants were followed for the subsequent 7 years. Because it is a live virus vaccine, the nasal influenza vaccine (LAIV) is not recommended in pregnancy.
The Centers for Diseases Control and Prevention (CDC) have published recommendations for immunizing pregnant women. These guidelines list vaccines that are recommended for all women, recommended for women in special medical circumstances and vaccines not recommended in pregnancy.