Sep 16, 2013

    Kids risk getting pertussis if vaccination delayed

    CHILDREN who are not vaccinated according to the schedule recommended by United States health officials are at an increased risk of catching whooping cough, according to a new study.

    Researchers found that kids who fell significantly behind on their diphtheria, tetanus and acellular pertussis (DTaP) shots were between 19 and 28 times more likely to be diagnosed with whooping cough, also known as pertussis, than children who were vaccinated on time.

    "What we found - not surprisingly - was that kids who were not vaccinated on time were at a greater risk of pertussis, compared to those who were vaccinated on time," Mr Jason Glanz, the study's lead author from the Kaiser Permanente Colorado Institute for Health Research in Denver, said.

    Studies have shown that pertussis cases are on the rise across the US. Researchers suspect that is due to the use of a new type of pertussis vaccine - which has fewer side effects, but is less effective over the long run - and to more children missing or delaying vaccination.

    Mr Glanz said common side effects of the vaccine include fever, discomfort and a sore arm. Serious side effects are rare, he said, adding that parents should understand that delaying their kids' vaccines puts the children at a greater risk of catching pertussis.

    Although parents sometimes believe delaying their children's vaccines and following alternative schedules is safer, Mr Glanz said there is no evidence that they are "any safer in terms of adverse events than what's typical".

    The US Centers for Disease Control and Prevention recommends children receive doses of the DTaP vaccine at two, four and six months of age, another dose between 15 and 18 months and a booster shot when they are four to six years old.

    The researchers found about 47 per cent of children diagnosed with pertussis were not vaccinated according to that schedule, versus about 22 per cent of kids in the comparison group.

    Mr Glanz's team also found that the longer parents delayed getting their children vaccinated, the higher the kids' risks of catching pertussis climbed.

    Those who were three doses behind, for example, were 19 times more likely to get whooping cough than kids who caught up on their shots, and those who were four doses behind had 28 times the risk.