by Mary Ryngaert
December 02, 2008

There may be hope for infants at risk for whooping cough, thanks to a recent study published in the Journal of Pediatrics.

What is whopping cough?
Whooping cough is a highly contagious disease, also known as pertussis. The illness begins much like the common cold— runny nose, sneezing, mild fever, and cough. After the first week or so, the cough progresses into bursts of frequent, harsh coughs. In children, especially infants, the breath taken prior to the coughing spell has a characteristic “whoop” sound. These are sometimes called paroxysms. Those with the illness report feeling like they cannot catch their breath. Children often experience vomiting with these coughs, and are quickly at risk for dehydration as they battle pertussis.

The recovery from pertussis can take several weeks. The illness is particularly hard on infants. Complications may include apnea (lack of breathing), bacterial pneumonia, seizures, and encephalopathy (inflammation of the brain). The illness is responsible for 98 hospitalizations per 100,000 infants 0–5 months of age. Pertussis remains with us despite the long-term availability of the vaccination. The most common age for pertussis in infants is one month of age. Routine vaccination with the DTaP (diptheria, tetanus, and pertussis) vaccine is recommended. The first of five doses is given at the two month check-up and the remaining doses are given at 4 months, 6 months, 15–18 months, and 4–6 years.

Immunization of children is an important part of protecting them from illness. Cases of pertussis are on the rise in the U.S., from a low of 1,010 cases in 1976 to more than 25,000 cases in 2005. There are likely more cases that go undiagnosed or unreported. In 2005, the American Academy of Pediatrics issued a policy recommending a booster shot for children at the 11–12 year check-up, and for older teens until all teens are vaccinated. Though the illness is less severe in teens, the widespread use of the vaccine will likely mean less exposure for those most vulnerable—babies.

Benefits of the vaccine
Most often the benefits of DTaP vaccination outweigh the risks. But it is important to keep in mind that immunizations are not without risks. The change from a whole-cell pertussis vaccine to an acellular vaccine greatly reduced the adverse reactions. Mild side effects of DTaP vaccine include mild to moderate fever, tenderness and redness at the vaccine site, fussiness, and occasional vomiting. More severe side effects include long periods of crying, seizures, and high fever. Fortunately, these are rare. Most infants do well with acetaminophen (Tylenol) to reduce fever and discomfort. Parents should observe their infants carefully after immunization and call their primary care provider if they cannot bring the baby’s fever down with acetaminophen or if the baby is crying without relief or extremely sleepy.

Results of a study published in the Journal of Pediatrics indicate that beginning the whooping cough vaccine series to infants at age 6 weeks rather than 8 weeks may significantly decrease the risks of the illness to infants. Researchers used existing data to predict the value of accelerating the pertussis vaccine in order to reduce illness, hospitalization, and death from the disease. Early vaccination is not a departure from current recommendations—the recommendations allow for the vaccine to be given as early as 6 weeks of age. This timing choice is not uncommon if a family is moving or will be traveling and might risk missing the first vaccine date.

Research
Physicians from Vanderbilt and Wake Forest looked at whooping cough rates and vaccination in babies and used statistical analysis to examine the benefits of moving the DTaP vaccine two weeks early. Their analysis used illness data from 1990–1999 to average annual rates for pertussis nationally. The researchers then examined the information again, this time assuming that the Dtap vaccine was given at 6 weeks of age.

The results show that even a slight change from the typical vaccine schedule would prevent 1,236 cases of pertussis, nearly 900 hospitalizations related to the disease, and seven pertussis-related deaths in infants 0–3 months of age. In addition, moving up the second and third doses of the DTaP vaccine to 3.5 and 5.5 months of age (instead of the current recommendation of 4 and 6 months) could prevent over 500 cases, 520 hospital stays, and two deaths. The results of this study indicate that we can further reduce the risk of pertussis to infants by fast-tracking the vaccine. The authors caution that the study is only predictive and not based on real cases, but the results of analysis make a good case for a study. In communities where whooping cough is increasing, local health providers may well decide that early vaccination is an important strategy to protect infants.

Recommendations
Parents are understandably concerned about an accelerated immunization schedule. These concerns have been the subject of several posts here and here on baby gooroo. Vaccines are given early and frequently, and health care providers are adding new vaccines as they become available. Some parents are requesting that vaccines be spaced more, to reduce the vaccine load on the child. Dr. Robert Sears is the author of The Vaccine Book, a reference that suggests an alternative schedule for vaccinations that increases the number of health care provider visits, but spaces the vaccines further apart. Proponents of spacing and breaking up multiple vaccines argue that exposure to fewer vaccines at a time is better for the infant. But even Dr. Sears admits that there is no scientific basis for this departure from the normal schedule. Even so, many pediatric primary care providers will work with parents to space out vaccines. If you are concerned, ask your primary care provider about the plan that is best for your child.