It has been shown by Francis et al. (1), Stuart Harris et al. (2, 3), Horsfall et al. (4) and others that the titer of the neutralizing antibody for human influenza virus rises during a clinical attack of influenza. There is also evidence that the titer tends to fall during the post-infection period, and that uninfected contacts may show evidence of subclinical immunization during the time of epidemics. Few or no observations have, however, as yet been made on (1) the variations which may occur in the titer of these antibodies over any extended period of time or (2) the changes which may occur in the antibody for porcine virus. This paper is an account of observations which have been carried out on these two subjects. For this purpose a group of 22 adults (aged 20 to 45 years) living in Toronto were studied over a period of approximately three years. During this period there were two epidemics of an influenzal nature in both of which virus was isolated from patients. The first epidemic occurred in the early weeks of 1937, beginning in Toronto about January 16 and dying away about February 20. The second or 1939 epidemic began about February 7 and was definitely on the wane by March 15. There was a remarkable absence of any infection even remotely resembling influenza during the whole of 1938.
No takes yet. Share an insight, caveat, or question.
Hare et al. (1941) studied this question.