Dr. David Witt, the lead researcher and chief of infectious disease at the Kaiser Permanente Medical Center in San Rafael, California, said at the American Society for Microbiology Conference in Chicago on September, 19 2011 that even though the study still needs to be confirmed through more research, the results show that the vaccine loses its effectiveness after just 3 years. The result came as a surprise to all who believed that the vaccine was effective for 5 years. "I was disturbed to find maybe we had a little more confidence in the vaccine than it might deserve," said Dr. Witt.
As for now, the Centers for Disease Control and Prevention (CDC) recommend 5 shots (2, 4, and 6 months of age, 15-18 months of age and 4-6 years of age) for infants/children and a booster vaccine for pre-teens/adolescent (11-12 years of age). If you notice, there is a gap of 5-8 years between the first 5 shots and the booster shot.
When Dr. Witt started the study he was expecting that the outbreak would be common among unvaccinated population, but he was surprised to find that a group of fully vaccinated kids caught the disease at a high rate. "What we pretty quickly identify is that the bulk of the outbreak was in fully vaccinated children", he said.
"Older kids and younger kids seemed to be pretty well protected but the age of eight to 12 was the vast bulk of the cases. And when we examined that, it was correlated to being more than three years from the last vaccine booster dose."
The CDC states that last year, 27,550 cases of pertussis were reported in the U.S. (27 deaths - 25 of these deaths were in children younger than 1 year old). California had large number of pertussis cases last year, during which more than 9,100 people fell ill and 10 babies died. Middle and high school students who haven't gotten their booster shot, were not allowed by the school to return this fall.
Whooping Cough is a highly contagious disease caused by Bordetella pertussis that can be fatal, specially in infants too young to be fully vaccinated. The symptoms starts like the common cold, with runny nose or congestion, sneezing, and maybe mild cough or fever. But after 1–2 weeks, severe coughing can begin. It is characterized by a "whoop" sound when air is inhaled and vomiting after a coughing spell.
The symptoms in infants are different. The cough can be minimal or not even there and they may have a pause in the breathing pattern (apnea).
The CDC disagree with the results of this study. Heath officials are now debating about the need of giving the booster shot to children as young as 7 years old, but as for now, Federal officials says that is still too soon to make that a standard practice.
If you have a 7-11 years old child, ask/talk to your doctor about a booster shot.
Note: The CDC recommends that adults 65 years and older who have close contact with infants should get a Pertussis shot.
Picture's source: http://www.freedigitalphotos.net/images/Healthcare_g355-Female_Doctor_And_Syringe_p27460.html
ADDENDUM (09/26/2011 14:30 p.m.):
The American Academy of Pediatrics (AAP) published in the October issue of Pediatrics a revised policy about whooping cough vaccination.
The AAP and the CDC are now recommending that ALL adults who have contact with a child to get vaccinated against whooping cough, considering that they are often transmitting the disease. The vaccine is called Tdap, a combination of three vaccines that protect against tetanus, diphtheria and pertussis.
As stated by Dr. Peter Richel, chief of pediatrics at Northern Westchester Hospital, in Mount Kisco, N.Y., "In addition to the above recommendations during childhood, Tdap should be received by adults…pregnant women and caretakers of infants and children,". "That means day care workers, teachers, and parents and grandparents of any age. If you have any questions, refer to your pediatrician, obstetrician or internist."