Can breastfeeding prevent whooping cough?

Every weekday, a CNNHealth expert doctor answers a viewer question. On Monday, it's Dr. Jennifer Shu, a pediatrician.

Question asked by Sara of Decatur, Georgia:

I am six months pregnant and have a couple of questions about babies who have recently died from whooping cough in California. How were they introduced to the bacteria? Can breastfeeding prevent this illness?

Expert answer:

Thanks for your question. Whooping cough, an illness caused by the pertussis bacteria, can cause severe respiratory symptoms and even death in young infants. In 2010, nearly 6,000 cases of whooping cough (including 10 deaths) have been reported so far in the state of California alone.

Officials report that half of the children who were sick probably got the infection from a parent or another caregiver and that nine of the 10 deaths occurred in infants under 2 months of age.

Older children and adults who have whooping cough often appear to have a bad cold or persistent cough that can be so severe that it causes vomiting. If left untreated, they usually get better on their own after several weeks, but giving antibiotics may help shorten the illness as well as decrease how contagious they are.

On the other hand, babies can become very ill from whooping cough. Because of their young age, immature immune system and delicate lungs, they are also more likely to have problems such as pneumonia, apnea (pauses or stoppages in breathing) or seizures related to the infection.

Babies under 6 months of age often do not make the typical "whooping" noise when they breathe in before coughing, so the diagnosis may sometimes be overlooked.

Although antibodies pass through the placenta to the baby during pregnancy, the ones that protect against pertussis are thought not to transfer well enough to help infants in the first few months.

Breastfeeding can certainly help provide immune protection against multiple illnesses, but not if a mother does not have immunity to a certain disease such as pertussis.

Since the pertussis vaccine's protection can wear off with time, a booster shot is recommended for adolescents at their 11-year-old checkup visit, as well as for adults who care for young infants, in order to protect from whooping cough until the babies have their own immunity.

This vaccine is given as Tdap, a relatively new vaccine that adds the pertussis component onto the original Td, or tetanus/diphtheria, booster shot. If it has been more than two years since a parent or caregiver had their last tetanus shot, the Tdap vaccine will be recommended now and again about every 10 years.

Infants typically receive the first part of the pertussis vaccine series at 2, 4 and 6 months as a component called DTaP. Until they get all three of these shots, they are more vulnerable to catching the disease.

For more information, I hope you will consult with your obstetrician or midwife for the best recommendations for your situation. Good luck!