Scientists have called the efficacy of this vaccine into question, spurring a massive debate about whether or not it is necessary.
A common booster vaccine for whooping cough, called Tdap, is required by many states for middle school aged children. According to a CNN report, however, a recent study from researchers at the Kaiser Permanente Vaccine Study Center in California suggests that even though multiple states mandate the vaccine, it may not actually be all that effective.
The Tdap booster primarily protects against pertussis, commonly known as the whooping cough, in addition to tetanus and diphtheria. In a study examining over 280,000 children from 2009 to 2015, researchers found that the booster protected roughly 69 percent of adolescents in their first year after receiving the vaccine.
The protection appeared to wear off rapidly, however; after the second year, 57 percent of adolescents who had the booster were protected from whooping cough, while 25 percent were protected after the third year, and only nine percent after the fourth year. Nearly all of the children in the study had received the vaccine before age 11 or 12, as it is mandated before a student can enroll in California public middle schools.
According to Dr. Nicola P. Klein, the co-director of the Kaiser Permanente Vaccine Study Center and the study’s lead author, “It provides moderate protection during the first year but years two and three after vaccination, there is not that much protection left.”
Previous research had suggested that there was a need for the Tdap booster in the first place, as the preliminary five doses of DTaP vaccine for children were shown to fade in effectiveness over the years. The booster is given to early teens to fill in the immunity gap, but the recent study suggests that even this may not be enough to adequately protect against whooping cough.
Despite the vaccine’s apparent lack of efficacy, whooping cough remains a mild and easily treatable disease, marked by a moderately heavy cough that can result in a few days home from school. Small babies are at the highest risk from the disease, and the vaccines, if anything, help prevent transmission to infants.
A press release from Kaiser Permanente describing the details of the recent study can be found here.