Mid-Winter finds the collective health of the entire University population at an almost all-time peak. Absences from classes because of illness have been practically non-existent; people who formerly carried their coughs into examinations and theaters seem temporarily to have dropped out of sight; in a year when University enrollment has doubled, the number of patients in Stillman stands at one-third of the normal figure. Data from hospitals throughout the Boston area testify that the notable absence of colds, pneumonia, and other respiratory ailments is not something peculiar to Harvard. While such a situation is indeed heartening, in another sense it is almost ominous, as if the world were temporarily becalmed, waiting for a vast storm of disease to strike.

The most portentous threat lies in the fact that the United States now stands at the wrong phase of two distinct influenza cycles. An influenza pandemic, which recurs every twenty to thirty years, has not been visited upon the world since 1918, when it killed twenty-one million people of whom half a million were Americans. The pandemic virus has been due to strike again since 1937. Less powerful viruses, the more common influenza "A" or "B", tend to run in five or six year cycles. Both are set for a re-appearance, since neither has been detected in epidemic form since before the war.

Wary of the impending epidemic or pandemic of influenza, the medical authorities at Yale recently vaccinated, free of charge, every student in the university. Harvard has not followed suit for a number of reasons. The only vaccines which have been developed so far are not effective against the dangerous pandemic form. Vaccinations for virus "A" do not protect against virus "B", and "B" vaccine is ineffective against a wave of "A" cases. For all types, the duration of the immunity is indeterminate, with the only sure fact being that the guarantee against contraction of the disease becomes less certain as time passes.

But if the Hygiene Department is justified in withholding vaccinations, it cannot afford to point with pride at the empty beds in Stillman and dismiss the problem. If the charts are to be believed, a world already weakened by war stands on the threshold of another disastrous flu pandemic. The policy of the University medical men must be one of watchful waiting. They should decide now how best they could vaccinate men wholesale in case of emergency. They should assure ready access to stocks of vaccine, if and when an epidemic strikes. The storm signals are flying; the Hygiene Department must batten its preventive hatches.