Development of a live attenuated varicella vaccine.

The Oka strain of varicella virus, isolated in our labolatory, was serially cultivated in guinea-pig embryo cultures (GPEC), and a considerable amount of cell-free virus was obtained from infected cell. GPEC passage virus at the 6th passage level was used in a small scale field trial. Susceptible children of 1 to 10 years old were injected subcutaneously with 100 to 1,000 PFU of virus. No clinical reactions due to the vaccination were observed in any children, and a high rate of antibody response was obtained with viral doses of more than 200 PFU. Attenuated virus obtained by passage in GPEC was propagated in human diploid (WI-38) cells, and it was also effective in inducing an immune response without clinical reactions. The results show that the Oka strain of varicella virus passaged in GPEC and human diploid (WI-38) cells may be used safely and effectively as a live attenuated vaccine.     

Encephalitis after administration of live measles vaccine.

In a previously well child with no evidence of pre-existing immunologic defect a fatal encephalitis developed 10 days after administration of measles vaccine. There was pathologic evidence of an early viral encephalitis characterized by perivascular mononulcear infiltrates. Although the virus was not recovered, the diagnosis of a measles virus infection and encephalitis is supported by the postmortem findings of Warthin-Finkeldey cells in lymphoid tissues, an intranuclear inclusion in the brain and histologic changes of encephalitis.     

The vaccine is dead--long live the vaccine

An important chapter in the search for a vaccine against malaria, that of the anti-Plasmodium falciparum vaccine candidate SPf66, has been effectively closed. A Cochrane review of ten major efficacy trials in endemic areas concluded it 'has little or no effect on preventing malaria'. This provides an appropriate opportunity to reflect on the perspectives for current and future vaccine formulations against Plasmodium.