ACAMBIS STUDIES WEST NILE VACCINE IN OLDER ADULTS

Acambis has begun testing its investigational West Nile virus vaccine, ChimeriVax-West Nile, in older adults, those most in need of protection against West Nile virus, the company announced. The ChimeriVax-West Nile is the most advanced West Nile virus vaccine in development, according to Acambis.

The randomized, double-blind, placebo-controlled study is the second part of a Phase II trial evaluating the vaccine. The trial is designed to evaluate the safety, tolerability and immunogenicity of ChimeriVax-West Nile and is being conducted in the U.S.

Previously, Acambis announced encouraging results from the first part of the Phase II trial, which involved adults ages 18 to 40. More than 97 percent of subjects who received a single dose of ChimeriVax-West Nile developed neutralizing antibodies above the predefined cut-off level 28 days after vaccination. The majority of adverse events were mild in nature.

ChimeriVax-West Nile is being developed to provide a safe, single-dose West Nile virus vaccine for at-risk individuals. Development of the investigational vaccine was supported by a $3 million grant from the NIH. It is a live, attenuated, injectable vaccine developed using Acambis' proprietary ChimeriVax technology.