Whooping Cough Vaccine May Not Give Long-Term Protection
Study Suggests Protection From the Vaccine May Lessen After 3 Years
Revising the Immunization Schedule continued...
The greatest fear is transmission to infants who cannot be fully vaccinated until they are 6 months of age, he says. "Families are at risk of transmitting to infants. We know the vaccine mitigates the impact, but it is still dangerous to younger siblings."
Witt recommends vaccination even while the optimal schedule is debated.
"We still find there was a higher risk among unvaccinated children in Marin County. Any group that is unprotected multiplies the risk to the rest of the community," he says.
Plus, vaccination appears to offer good protection for at least two to three years and may help symptoms to resolve more quickly, he notes.
About 8% of Marin County residents are not vaccinated against whooping cough, Witt says.
Whooping Cough in Adults
Illness can be severe, even in adults, according to Witt.
"We know there are ongoing outbreaks among adults. We know that adults represent a reservoir for the disease. We still have a large unimmunized herd that is a danger to young infants," he says.
The benefits of vaccinating beyond school age were questionable with the previous vaccine. But in the late 1990s, the nation started using a new type of whooping cough vaccine that has fewer side effects, making adult vaccination more feasible, he says.
Patti tells WebMD that preliminary results of a study of the new vaccine show "modest waning each year after, but still some protection even five years out."
Final results from that and another study of the vaccine will be presented at an infectious diseases meeting in October.
Whooping cough infects 30 million to 50 million people worldwide each year, killing about 300,000, according to the CDC.
The infection typically starts out with cold-like symptoms but progresses to a dry, hacking coughing fits that last up to 10 weeks. It can be fatal, especially in infants. It is typically treated with antibiotics, which help relieve symptoms and prevent spread.
These findings were presented at a medical conference. They should be considered preliminary as they have not yet undergone the "peer review" process, in which outside experts scrutinize the data prior to publication in a medical journal.