The injection of two of three anti-flu vaccines at certain intervals, which have been developed in preparation for an outbreak of a new type of flu, are effective in preventing flu symptoms from becoming serious, (Snip) The research team made the discovery after conducting clinical tests on three types of pre-pandemic vaccines that it has made from the highly-virulent bird flu virus H5N1. The ministry will determine the best method and timing for the vaccinations by the end of this year, (Snip)

In the clinical tests, 210 test subjects were inoculated with a vaccine based on a virus strain that a human was infected with from a bird in Vietnam, (Snip) Three years later, they received an injection of either of the two other types of vaccine made from virus strains obtained in Indonesia and China.

It has turned out that about 67 to 96 percent of the test subjects became immune to the other type of virus, against which they were not vaccinated, three weeks after the second injection. Moreover, it has proven that an additional vaccination helped improve the immunity of those who had received prior vaccinations only one week later.

“If the genotype of the vaccine is similar to that of a new type of flu, prior vaccination will likely be effective in preventing those who are infected from becoming seriously ill or dying,” Ihara said. Moreover, 2.8 percent of 5,561 medical workers who were inoculated with a vaccine with the same type of gene suffered from side-effects such as high fever. Eight of them were hospitalized. The ratio of hospitalization is almost equal to that of medical professionals who were not inoculated, and the rate of those who developed side effects is close to that in past similar tests.