Pertussis is a highly contagious respiratory disease that causes violent, uncontrollable coughing that makes it hard to breathe. Commonly known as whooping cough because of the "whooping” sound patients make, it often starts with a runny nose, mild cough, or low-grade fever. Newborns with pertussis may not cough at all; instead, they might stop breathing and turn blue.
Whooping cough is spread like a common cold, through coughing or sneezing. When adults and teens are infected with a mild case of pertussis, they may not show symptoms and may unknowingly spread the disease to your baby.
In about half of cases, infants are most likely to be infected by an immediate family member, most frequently mothers and siblings.
Especially in babies younger than 2 months old, pertussis can be fatal. Since infants can’t be vaccinated until they’re 8 weeks old, newborns rely on maternal antibodies to fight off pertussis infections.
Now we have a large body of data showing that maternal vaccination in pregnancy helped significantly reduce whooping cough cases in babies younger than 2 months old.
A history of whooping cough vaccination
From 2006-2012, the Centers for Disease Control and Prevention (CDC) made a series of recommendations to prevent newborn deaths from whooping cough:
- 2006: Any family member or caregiver expected to be around a newborn should be vaccinated at least two weeks before coming in contact with infant. The pregnant patient should be vaccinated in the postpartum period.
- 2011: Pregnant patients who had not previously been vaccinated with the tetanus, diphtheria, and pertussis (Tdap, pronounced “tee dap”) vaccine should do so during pregnancy.
- 2012: All pregnant patients, even those who had been previously vaccinated, should get a dose of Tdap in their third trimester of pregnancy.
The 2012 recommendation was considered drastic; vaccination of pregnant women focused on preventing newborn infections, not a maternal health benefit.
But data published in JAMA Pediatrics in February 2023 show that the strategy was effective. Researchers looked at the rate of pertussis infections over time that included the years before the 2012 recommendation and for several years after. They compared the rate of infections in infants younger than 2 months old (too young to be vaccinated themselves) with those who were 6-12 months old (who could be vaccinated).
Since maternal Tdap vaccination was recommended, there has been a significant reduction in the number of cases in infants younger than 2 months old:
- In 2012, right before the start of the universal vaccination recommendation the rate was 205 cases in 100,000 infants under 2 months of age.
- By 2016 it had declined to 75 cases/100,000 infants in that age group. During the same time period, there was no change in the rate of infection in older infants.
When you think about there being about 3.6 million births in 2021 alone, maternal vaccination helped prevent a large number of infections.
How to protect your baby from whooping cough
Just as it does for the flu, maternal immunization during pregnancy offers critical protection for newborns. About two weeks after receiving the shot, your body will produce antibodies that will cross the placenta, enter your baby’s bloodstream, and shield your infant after birth. Getting vaccinated also decreases your chance of catching this illness and passing it on to your baby.
With Tdap, the level of antibodies in your body declines over time. This means a woman needs to be immunized during every pregnancy for maximum benefit to each baby.
There’s no harm in receiving multiple Tdap boosters, and there are no risks to the pregnancy. Infants whose moms received the immunization will still produce normal amounts of antibodies when they start receiving their own whooping cough immunizations at 2 months of age. Babies can be considered fully immune after a series of vaccines given at 2 months, 4 months and 6 months of age.
Maternal vaccination during pregnancy isn’t a perfect solution. Infants whose mothers received the vaccination during pregnancy can still catch pertussis. But we know that babies whose moms received Tdap vaccinations during the third trimester are much less likely to become ill than those whose moms waited until after delivery.
What to do if you didn’t get a Tdap vaccine
If you have a newborn and did not receive a Tdap booster in pregnancy, ask your doctor about a potential treatment called postexposure antimicrobial prophylaxis (PEP). PEP is antibiotic therapy given to people who might have been exposed to whooping cough before symptoms arise.
The CDC recommends giving PEP only to people who are at high risk of severe pertussis and people who have close contact with them, such as:
- Babies younger than 12 months
- Pregnant patients in the third trimester
- People who are immunocompromised
- People with pre-existing health conditions, such as severe asthma
- People working with children and pregnant or postpartum patients, such as pediatric health care, maternity centers, or childcare settings
PEP should only be used in specific cases to prevent serious infections or death in patients at high risk. This strategy is currently used for newborns exposed to COVID-19 and influenza – both conditions in which maternal vaccination improves outcomes for newborns.
Getting a Tdap vaccination for yourself and your family is the best way to reduce the risk of whooping cough infection.
Decrease your baby’s risk of exposure
A second strategy for protecting your baby is called “cocooning.” By making sure people who come into contact with your baby are vaccinated against pertussis, you can reduce the likelihood your newborn will be exposed to the infection. Encourage family members, babysitters, and friends to get a Tdap shot at least two weeks before they meet the baby. The vaccine is widely available at retail pharmacies and doctors’ offices.
Don’t be shy about keeping your newborn away from people who have cold symptoms or are coughing. They will just have to understand you are being cautious. Also be wary about taking your baby out into large groups of people; someone may have whooping cough and not realize it.
Finally, we strongly encourage expectant moms to ask your doctor for a Tdap vaccination during the third trimester. It can provide protection for you and your baby.