New vaccination method developed

Researchers have developed a new vaccination method for rotavirus, one of the common causes of severe diarrheal disease that causes approximately 500,000 deaths among children in developing countries annually.

The vaccine, reported in a study published in the November issue of Clinical and Vaccine Immunology, is delivered in nasal drops and was successful in inducing an immune response in rats to protect them from rotavirus infection.

“The new vaccine, in conjunction with an agent that enhances immunity, induced sufficient antibody formation against rotavirus to protect mice against infection when the mice were exposed to rotavirus three weeks after their third immunization,” John E. Herrmann, senior author of the study, said.

The delivery system for the vaccine has been found to be heat stable with tetanus and is being tested for pertussis and diphtheria. If the method is found to be heat stable, this would circumvent a major problem in current vaccines, which must be stored in freezers or refrigerators until the moment they are administered. This is difficult in parts of the world where there is insufficient electricity and refrigeration.

“A needle-free approach to vaccination is particularly advantageous in developing countries where clean needles and syringes and trained personnel are not always available,” Abraham L. Sonenshein, the team leader for the researchers, said. “The next major step for these vaccines is to show that they are safe and work well in humans, and then to extend the rotavirus and tetanus vaccine technology to include diphtheria, pertussis and other infectious diseases.”

The new method was tested with harmless bacteria that had been engineered to display the rotavirus protein.

“The vaccine (which is created) with the Bacillus bacteria is very inexpensive to product in large quantities and, unlike most traditional vaccines, requires no special purification steps before use,” Saul Tzipori, director of the Infectious Diseases Division of the Department of Biomedical Sciences at the Cummings School, said. “As a result, the cost of vaccine production is unusually low.”