A vaccine against smallpox in tissue culture seems promising third-generation, Japanese researchers report.
“The threat of the use of smallpox virus as a weapon of bioterrorism has led to reconsider the need for a vaccine against smallpox,” the researchers said. “The serious events associated with first generation vaccines have raised barriers to vaccination campaigns in the U.S. UU.”
The second generation vaccines also cause a high rate of serious side effects, they said.
“Developing a vaccine that is safer than first-generation vaccines but highly immunogenic [to produce immunity or immune response] is crucial for the design of a prevention plan in the event of bioterrorism attacks,” they added.
The researchers studied immune responses to vaccination in 1.692 LC16m8 adults who had been previously vaccinated against smallpox and 1.529 that had not been vaccinated. The LC16m8 is a live attenuated vaccine (reduced power).
The participants were examined between ten and fourteen days after the application of the vaccine. The researchers found antibodies in about 90 percent of those who had not previously been vaccinated, and reinforced an effective response in 60 percent of those who had been vaccinated previously. None of the participants experienced serious side effects.
The study “provides evidence for the safety of the vaccine LC16m8 in adults,” wrote Dr. Tomoya Saito, University of Tokyo and his colleagues. “The vaccine LC16m8 appears to be a viable alternative to vaccines first, second and other third generation in a program of preparedness for a possible bioterrorist attack with smallpox virus.”
The study appears in the March 11 edition of the Journal of the American Medical Association.