Laws mandating flu vaccines for health care workers increase their vaccination rates, according to a new study.

The study, published in the Journal of the National Medical Association, examines the relationship between state laws regulating flu vaccines for health care workers and the state-level immunization rates among health care workers between 2001-2011.

From 2000 to 2005, only two states, Maine and New Hampshire, had flu vaccine requirement laws for health care workers. During that period, the average flu vaccination rate for health care workers was 22.5%. In 2006-2011, when 19 other states passed their laws, the average vaccination rate for health care workers increased to 50.9%. While flu vaccination rates among health care workers have been increasing gradually over the past few years (up to 66.9% in 2012-2013), rates are still lower than what is recommended by Healthy People 2020 (90%).

The study applied scores to measure strength of vaccine laws. Some laws mandated that health care employers pay for the vaccines. Others required formal documentation, education and reporting of vaccination rates.

“We’re finding that the higher the score — meaning the state has a law and includes components like a mandate or education — the greater the probability that the vaccination rate among health care workers will be higher,” said Dr. Chyongchiou Jeng Lin, PhD, the study’s lead author at the University of Pittsburgh School of Medicine, Department of Family Medicine.

Advisory committees and health care organizations like the CDC Advisory Committee on Immunization Practices has long recommended that all health care workers receive an annual flu vaccine to reduce the spread of the flu among staff and patients, and to decrease staff absenteeism.

Previous research funded by the Public Health Law Research program has shown that individual hospital policies have a clear and marked effect on flu vaccination rates among health care workers in acute care facilities. 

This study, the authors note, identifies options for policy makers in areas where individual facility-level mandates may not be possible.

“State laws may be a viable option for states looking to increase health care worker flu vaccine rates, but where the health care environment may not be conducive to a facility-based mandate,” Dr. Lin said. “This is one more tool in a policy maker’s tool box to support health care workers and continue to protect their patients.”

Since the study, a few states have added laws in some ways addressing flu vaccine requirements for health care workers. As of 2014, 33 states have laws that address health care worker flu vaccination in hospitals and/or long-term care facilities including: Alabama, Arizona, Arkansas, California, Colorado, Connecticut, Florida, Georgia, Illinois, Indiana, Iowa, Kentucky, Maine, Maryland, Massachusetts, Michigan, Montana, Nebraska, New Hampshire, New Jersey, New York, North Carolina, Ohio, Oklahoma, Oregon, Pennsylvania, Rhode Island, South Dakota, Tennessee, Texas, Utah, Virginia, and Washington.