Our analysis found no significant increase in reported cardiac deaths after the 1947 mass smallpox vaccination campaign in NYC. The 4-week period was identified as April 16 to May 13 and included 99% of the at-risk person-time. The 2-week at-risk period in 1947 was estimated to be April 22 to May 5, which encompassed 84% of the projected at-risk person-time for adverse cardiac complications. While this power would be more than sufficient to detect an excess of 2 deaths in 29,584 civilians (approximately 400 deaths in the 1947 NYC population of 6,000,000), it would not be able to detect very small elevations in risk.Īt the height of the 1947 vaccination campaign, from April 17 to April 21, 500,000 to 1 million people were vaccinated daily ( Figure 1). Additional models examined subsets of cardiac disease and all-cause death as outcomes, as well as adjusting for noncardiac death volume.Īn a priori power analysis found that the model had >90% power to detect a 5% increase in cardiac fatalities in the at-risk period. The main model included all cardiac deaths as the outcome variable and a dichotomous “exposure” variable indicating whether the death occurred during the 2-week risk period. Secular trends were modeled with linear and quadratic terms. We also adjusted for temporal trends in the data: a long-term trend from 1946 to 1948 (defined by weeks since January 1, 1946) and a seasonal trend between March and June (defined by days since March 1 for any given year). Counts were used instead of rates, as NYC’s population remained relatively constant during the study’s 3-year timeframe. We used Poisson regression, a generalized linear model appropriate for analysis of discrete data, to model counts of cardiac deaths ( 7). We compared daily death rates during the postvaccination risk periods with rates at other times during the study period. We defined cause of death as “cardiac” if the ICD-5 codes for either cause included pericarditis (090), acute endocarditis (091), chronic endocarditis (092), myocardial disease (093), coronary artery diseases (094), and other disease of the heart (095). We abstracted the date of death, age of decedent, and ICD-5–coded primary and other cause of death into an electronic database. Cause of death was coded according to the International Classification of Diseases, 5th Revision (ICD-5) ( 6). We obtained all death certificates issued in NYC for the 4-month period between March and June, 1946–1948, from the NYC Municipal Archive.

On the basis of these estimates, we identified the 2- and 4-week “peak” risk periods in 1947. Since all of the 2003 cardiac events occurred from 4 to 17 days after vaccination, the 1947 vaccination numbers were divided equally across the same 14-day period to calculate the person-time at risk for potential cardiac death. We used newspaper accounts and NYC Department of Health records to estimate the number of adults vaccinated on each of the 29 days ( 5). We provide full results and additional methodologic detail here.įrom April 4 through May 2, 1947, 6.35 million New Yorkers were vaccinated with the NYC Board of Health vaccinia strain ( 5). Key findings were published in an earlier article ( 4). To ascertain whether cardiac deaths increased after a large 1947 smallpox vaccination campaign in New York City (NYC), we examined death certificates from a 4-month period in 1947 as well as from comparable periods in 19. Whether these ischemic deaths were vaccine-associated or co-incidental is unclear. By March 28, four nonfatal and three fatal myocardial infarctions (MIs) had been reported. From December through April 2003, smallpox vaccine was administered to 29,584 civilians and 365,000 military personnel nationwide ( 2, 3).

government initiated a campaign to immunize the American military and civilian first-responders in the event of an intentional release of the smallpox virus ( 1). After the terrorist events of September and October 2001, the U.S. Smallpox was successfully eradicated in 1980 after a global vaccination campaign by the World Health Organization.

Dr steven schwartz atlanta georgia