Laws promoting flu vaccination in hospital workers associated with improved mortality rates

From 1995 to 2017, 13 states and the District of Columbia have passed laws on flu vaccine in hospital workers, most requiring hospitals to provide vaccination onsite for employees and some mandating vaccination or face masks for unvaccinated workers.


State laws promoting flu vaccination among hospital workers may help decrease mortality for flu and pneumonia in the community, a recent study found.

Researchers performed a quasiexperimental observational study to evaluate the effect of state-level laws regarding flu vaccination in hospital workers on pneumonia and influenza mortality. Data on pneumonia and influenza mortality per 100,000 persons by state and by month, population-wide and by age group, were obtained from the National Vital Statistics System for 1995 to 2017. During this time period, 13 states and the District of Columbia passed laws on flu vaccine in hospital workers, most requiring hospitals to provide vaccination onsite for employees and some mandating vaccination or face masks for unvaccinated workers. Six of the 14 laws also included health care workers outside the hospital setting. Changes in mortality rates for states that adopted these laws and those that did not were compared using linear and log-linear models. The study results were published Jan. 5 by Annals of Internal Medicine.

The study's main analyses looked at 17 influenza years from 1995-1996 through 2016-2017 in which the vaccine was well matched to the circulating virus strains (five influenza years with match rates below 50% were excluded). The proportion of U.S. hospital workers who were subject to a flu vaccine law ranged from below 2% in 1995 to approximately 38% in 2017. Rates of hospital worker influenza vaccination rates doubled from 43% in 1997-1998 to 87% in 2016-2017. In the years when the flu vaccine was well matched to the circulating strains of the virus, implementation of state laws requiring hospitals to offer vaccination to their employees was associated with a 2.5% reduction in monthly mortality rates for pneumonia and influenza (−0.16 death per 100,000 persons [95% CI, −0.29 to −0.02]; P=0.022). The largest effects were seen for elderly people and during peak influenza months.

Among other limitations, the researchers noted that they did not have information on hospitals' independent vaccination requirements and that their study used large-scale national data and they could therefore not evaluate the effect of vaccination on more specific outcomes. They concluded that state laws promoting flu vaccination for hospital workers may help prevent deaths related to influenza and pneumonia, particularly among those who are elderly. “Overall, our findings are consistent with the idea that vaccinating hospital workers reduces the spread of influenza and, by doing so, protects the lives of more vulnerable populations,” they wrote.

A Q&A on vaccination of health care workers for COVID-19 appeared in the Dec. 9, 2020, ACP Hospitalist Weekly.