A recent study has revealed that the Tdap booster is faltering in its efficacy in the years after it was given to teens that have been given the newer versions of the 5 part CTaP vaccine, which is meant to provide protection from a whooping cough, tetanus, and diphtheria.
The protection afforded by the vaccine booster falls short and after four years it remains less than 10%.
The current DTaP vaccine was introduced in the 1990’s after the earlier DTwP, which was in use since 1950’s was producing some undesirable side effects.
The DTaP vaccine uses proteins from the pertussis bacteria while the more initial DTwP vaccine contained whole inactivated cells.
There have been some outbreaks of pertussis in recent years which has been blamed on incomplete rounds of vaccination, but also falling efficacy over time. The DTaP is administered to kids of 2, 4, and six months of age.
Booster shots are given in between 15 and 18 months and between 4 and six years old for complete protection. An additional booster Tdap is recommended for kids between the age of 11 and 12 years.
Dr. Nicola Klein, co-director of the Kaiser Permanente Vaccine Study Center, said in a press release that the approach of regularly vaccinating grownups to preempt future disease did not succeed in preventing the 2014 epidemic since the immunity afforded by a dose of Tdap was short lived.
Until better and longer acting vaccines are developed, alternative Tdap immunization strategies for adolescents must be devised.
The study has been published in the ‘Journal Pediatrics’ and involved analysis of 1,207 pertussis cases of young patients of Kaiser Permanente Northern California’s managed care who were vaccinated with DTaP vaccine between 2010 and 2014.
The study revealed that the booster dose afforded a 69% protection to teens against pertussis which reduced to 57% in the second year and fell to 25% in the third year of falling to 9% in the fourth year.