New Vaccines for Old Diseases
In chinchillas -- the best animal model for this type of infection -- a mixture of these specific bacterial proteins protected half the animals from infection by bringing about an immune response, and most of the animals that did get infected had lower levels of the bacteria in their ears.
There is an even further refinement of this vaccine, which uses these bacterial proteins in combination with another type of protein found on some of the bacteria.
"The thought is that we might be able to make a combination vaccine [with both of these types of proteins]," Barenkamp says. "We are just getting into clinical trials, but there is no human data yet."
While the otitis media bacteria is a major cause of chronic sinus infections in adults, Barenkamp tells WebMD that he is doubtful that the vaccine will offer an effective treatment for these patients. "I'm not convinced that adults would benefit from this vaccine," he says. "I think this would primarily be to prevent childhood infections."
Another conference presentation considered the use of an existing vaccine -- the 'whooping cough' vaccine -- in a new population. Scott Halperin, MD, of Dalhousie University in Halifax, Nova Scotia, notes that adults and adolescents are the most rapidly growing population affected by pertussis in the U.S., Canada, the U.K., and Europe.
Pertussis is the bacterium that causes whooping cough in children. In adults, it can bring about persistent coughing, without the telltale 'whoop' that you would hear from a child's immature respiratory tract. Nonetheless, it is still a problem for teens and adults. An outbreak this year in Victoria, British Columbia, was responsible for hundreds of diagnosed cases, and perhaps 10 times as many more not properly diagnosed.
"In adults the mean duration of cough is 40 days," Halperin says. "In adults and adolescents there is zero [death rate] -- but coughing and staying awake for three to four weeks is terrible and well worth preventing."
In addition to adult illness, there is also risk that adults -- especially teen mothers -- will transmit the disease to infants. There now are two different adult formulations of the vaccine. One is licensed in Canada and one in Germany; neither is currently available in the U.S.