[Skip to Content]
[Skip to Content Landing]
July 6, 1970

Efficacy of Intradermally Administered A2 Hong Kong Vaccine

Author Affiliations

From the Department of Preventive Medicine, University of Washington, Seattle 98105. This study was supported by the Vaccine Development Branch, National Institute of Allergy and Infectious Diseases, under contract No. PH 43-63-562.

JAMA. 1970;213(1):130. doi:10.1001/jama.1970.03170270070027

To the Editor:—  During the 1968-1969 A2/Hong Kong influenza epidemic, several studies testified to moderate efficacy of subcutaneously administered inactivated vaccine.1 Tauruso et al compared antibody response after intradermal and subcutaneous inoculation and induced better antibody response by intradermal (ID) route.2 The efficacy under field conditions was not tested. Since this route might not induce local antibody response in the respiratory tract, doubt was raised about the protective effect of intradermal vaccine.3The following experiment tested intradermally administered vaccine under natural challenge. In September 1968 employees of all offices of a local Seattle bank were offered the old formulation of polyvalent influenza vaccine (without the Hong Kong strain) by intradermal route. On Dec 23, 1968, at the peak of the influenza epidemic, employees in the downtown office of this bank only, were offered monovalent A2/ Hong Kong vaccine (Eli Lilly and Co.: 80 CCA units). Vaccine was