Less than half of children who receive a dose of flu vaccine return to receive a second dose.
Previously, the researchers behind the new study had found that text message reminders improved first-dose influenza vaccination rates among young children. The new paper, which is published in the journal Pediatrics, looked at what impact these reminders might have on second-dose flu vaccination rates.
Flu vaccine coverage remains low among young children overall. Children who require two doses of vaccine in one season are at particular risk - less than half of these children return to receive a second dose after receiving their first.
Principal investigator Dr. Melissa Stockwell, assistant professor of Population and Family Health at the Mailman School of Public Health and assistant professor of Pediatrics at the Medical Center, makes the analogy that only receiving one dose of vaccine is like "wearing half a bicycle helmet" for children who are in need of two doses.
Dr. Stockwell also emphasizes how time-sensitive second-dose vaccination is:
"Even in children who ultimately receive two doses in a season, the time interval between doses is often beyond the recommended 28 days. This leaves many unprotected when the virus begins circulating."
The researchers conducted a randomized controlled trial during the 2012-13 flu season across three community-based pediatric clinics in Northern Manhattan, involving children from 660 families who required a second dose of flu vaccine.
Most families believed that their child was protected from flu by one vaccine dose
The study reports that 71.9% of the families believed that their child was protected from flu after one dose. Most of the families studied were from Latino backgrounds and publicly insured, according to the researchers, and the children were aged between 6 months and 8 years.
All of the families in the study had a cell phone that could receive text messages. The children were randomized into three groups, categorized according to the type of text reminder - "educational," "conventional" or "written reminder-only" - received by their parents.
Among children in the educational text message reminder group, 72.7% were more likely to receive a second dose of flu vaccine, compared with 66.7% of the children in the conventional text message group and 57.1% in the written reminder-only group.
Parents generally reported liking the text messages, with 60.8% of the parents describing the reminders as either the main reason or part of the reason why they brought their children to receive the second dose of the vaccine, and 70.1% of parents reporting that it prompted them to bring their child in sooner.
The parents said that, as well as the text messages providing useful reminders, they also liked how the messages provided information in a quick way that did not require talking to anyone. The parents in the study also said they would recommend the text messages to other parents.
"Text message programs like these allow for health care providers to care for their patients even when they are not in front of them in the office, somewhat like a modern day house call," concludes Dr. Stockwell.
"This randomized controlled trial provides valuable information for establishing best practices for influenza vaccine text message reminders," she adds. "Important next steps will be to assess the impact of text message vaccine reminders in other populations as well as for other vaccines."