Wiebenga, N. H., W. D. Kundin (Dept. Microbiology, U. S. Naval Medical Research Unit No. 2, FPO San Francisco 96263), G. R. French and R. G. Kennedy. Epidemic influenza on a naval vessel in Hong Kong, 1968. Amer. J. Epid., 1970, 97: 59–67.—This report presents clinical and laboratory observations obtained from study of personnel of a US Naval vessel, the USS FINCH, after arrival in the Harbor of Hong Kong, B.C.C., at a time when infection with a variant of influenza virus had reached epidemic proportions. Data are presented to indicate that at least 47% of the ship's personnel were infected during their visit. The possibility of “protective” antibodies, on arrival, in about 28% of the crew was noted and the significance of this observation was considered. It was suggested that protective antibody resulted from natural exposure to intermediate variants rather than previous immunization or prior exposure to the epidemic variant of influenza virus that afflicted Hong Kong citizens during July and August, 1968.