Production and testing in the USA of influenza virus vaccine made from the Hong Kong variant in 1968-69.

The Division of Biologics Standards of the National Institutes of Health made the Hong Kong variant of influenza virus available to US manufacturers for study in August 1968 and provided them with the Aichi strain for production purposes on 9 September. The first lot of vaccine was released on 15 November; 15 million doses had been released by the peak of the epidemic, which occurred in the first week of January 1969 in the USA, and 20 million doses by the end of that month. Despite the tremendous effort made, however, it is questionable whether the use of the vaccine, necessarily in smaller quantities than the total released, had any detectable effect on the course of the 1968-69 epidemic. The author suggests that it is also doubtful whether the 1957 epidemic of Asian influenza in the USA was significantly affected by the larger amount of vaccine that was then available before the epidemic peak was reached. He stresses that priority must be given to research into the problem of making sufficient vaccine available in good time to counter a threatened influenza epidemic.