The importance of why all pregnant women should get the Whooping Cough(Pertussis)
shot (Tdap) in EVERY pregnancy
In recent years, there has been an increasing number of infants, children and adults
contracting Pertussis in Israel and the world. The main reason for this increase is due to the
decreasing immunity to Pertussis as people get older as the effectiveness of the
immunization decreases over time. Pertussis is a dangerous disease, especially for infants
under 6 months of age. Complications from Pertussis include pneumonia (more than 5%),
weight loss, encephalitis and even death. More than one-third of infants who contract the
disease under the age of 1 year will be hospitalized and some of them in the ICU.
The immunization for Pertussis is part of the regularly scheduled childhood immunizations in
Israel. The immunization gives excellent immunity and is very safe, but because the
immunization can only be given at 2, 4, and 6 months and there is not full immunity until
age 12 months, infants under 1 year of age are at high risk for infection.
How can you protect your newborn infant from Pertussis until she is completely protected
at age 12 months?
Protection can be provided to an infant via giving the vaccination to every woman at the end
her pregnancy (weeks 27-36). The immunization will cause the fetus to receive a large dose
of antibodies which will protect the infant until his own immunizations to Pertussis vaccine
will be effective at age 12 months. In addition, the immunization will protect the pregnant
mother from being infected with Pertussis and thus prevent her from infecting her baby.
Why is the Pertussis vaccine given together with Tetanus, Diphtheria, and Polio? Isn't this
dangerous?
There does not exist in the world any immunization just to Pertussis. Pertussis is always
found with Tetanus and Diphtheria and sometimes Polio is included as well. The Polio
vaccine that is included is killed virus and there is no contraindication to receive it in
pregnancy. This combination is well tested in pregnancy and large studies in England shows
that it gives good immunity to the mother and her baby.
Why does the Ministry of Health recommend the Pertussis immunization for EVERY
pregnancy?
Despite having been given the immunization in previous pregnancies (even if the previous
pregnancy was one year ago), it is important for the pregnant mother to reimmunize for
Pertussis because the levels of antibodies needed to protect the newborn infant are much
higher than the levels needed to protect an adult. In addition, the levels of antibodies from a
previous immunization in an adult decrease rapidly over the first few months after the
immunization. These antibodies are enough to protect the mother for a few years, but not
the fetus and newborn of subsequent pregnancies.
Side effects of the immunization
Occasionally there are mild side effects to the Pertussis immunization which can occur from
1-3 days after the immunization. Common side effects include redness, swelling, and
discomfort at the site of the immunization. Rarer side effects include nausea, vomiting, poor
appetite, dizziness, diarrhea, headache and fever. Allergic reactions including anaphylaxis
have been reported but these are very rare.
If a woman has received the tetanus shot (Td) in the previous 5 years, there may be some
increased risk of mild side effects like redness, swelling and fever but it this is
counterbalanced by the large benefit to the mother and child of protection against Pertussis.
Information mainly from Israeli Ministry of Health