Use of Temperature-Sensitive Mutants for Live, Attenuated Influenza-Virus Vaccines

Abstract

THE protective value of killed influenza-virus vaccines is well documented; however, these vaccines depart from the ideal in several respects.^{1 , 2} In most studies vaccine protects only about 70 per cent of those vaccinated. Immunity is often transient, necessitating the annual revaccination of high-risk groups. Parenteral administration is required, and stimulation of local respiratory-tract immunity, which may be of high protective value, is poor. There is a low but statistically significant incidence of local and systemic reactions that appears to be intrinsic to the administered viral antigens. Children, who are important as both victims and vectors of influenza, respond relatively poorly . . .