Bacterial meningitis, an inflammation of the membranes covering the brain and spinal cord, can cause brain damage and death. Existing vaccines cover four of five types of bacteria that cause the disease, but developing a vaccine against meningococcus B has been challenging because more than 300 strains exist.
For this study, researchers with Novartis, the pharmaceuticals giant, and the University of Florence in Italy bioengineered 54 immunogens, which are substances that can elicit an immune response. They then tested these immunogens in mice to see which ones encouraged the development of antibodies when exposed to diverse strains of meningococcus B. From there, they tested eight particular immunogens that triggered the best antibody response in a mouse model against a larger, more diverse group of meningococcus B strains. This experiment allowed them to pinpoint the most effective candidate.
“The cool thing about what these researchers did is that they bioengineered their own variant,” said Dr. Alka Khaitan, a pediatric infectious disease specialist at New York University Langone Medical Center in New York City. “The new technology would allow us to look at all the variations and then pick and choose the ones that are likely to be protective.”
More study is needed, but if the technology becomes widely available, it could also foster the development of vaccines for malaria and HIV, the virus that cause AIDS, she said. HIV and malaria also have many variations, which has hampered vaccine development.
The study results are published July 13 in Science Translational Medicine.
Meningococcal B is highly contagious. Infants are at highest risk of infection, and if they survive, they may end up with learning disabilities, hearing loss or loss of limbs, according to the study. Disease onset occurs so fast that antibiotics are sometimes unable to stop it.
“We have failed up to now to develop a vaccine, and we have seen epidemics related to meningococcus B,” said Dr. Bruce Hirsch, an infectious disease expert at North Shore University Hospital in Manhasset, N.Y.
“In a young healthy person, this strain can cause severe illness or death within hours, so the ability to prevent it in college dormitories, military recruits and crowded conditions is very important,” Hirsch said.
Dr. Peter D. Kwong, of the vaccine research center of the National Institute of Allergy and Infectious Diseases in Bethesda, Md., and co-author of an accompanying editorial, said the new technology may one day take the gamble out of developing the annual flu vaccine. Each year, scientists develop a vaccine based on projections and predictions.
“If we could develop one that provides quite broad protection against all flu strains, we may be able to have a general flu vaccine, so we don’t need a new one every season,” he said.
That said, many hurdles remain in terms of developing new vaccines, including safety and efficacy trials as well as cost and delivery issues.
SOURCE: Peter D, Kwong, Ph.D., Vaccine Research Center, U.S. National Institute of Allergy and Infectious Diseases