Vaccinations from nurses drove a significant increase in at-risk adults and older people who received flu or pneumonia shots, according to a new study.

Researchers said nurse-led intervention, which included calls or texts as vaccine reminders, was more effective than physician intervention and was among the best methods to promote vaccinations. The results were published in Annals of Family Medicine.

The findings could help make inroads into the low U.S. adult vaccination rate. According to a research brief in July, fewer than 70% of adults at the highest risk for influenza — or complications from influenza — were vaccinated as of 2009. While nursing facility resident compliance is typically much higher, employees there are lower.

Care and other fallout for influenza and related illnesses are costly. Depending on the severity of the season, influenza can cause up to $90 billion annually in lost productivity and healthcare spending, according to the brief.