Repeated text messages to encourage vaccination!

Vaccines have been a vital part of eradicating or controlling several deadly infections diseases in the past. But reaching high enough levels of vaccination coverage to attain herd immunity is often a challenge. So, while several safe and effective vaccines against COVID-19 are currently available, some 30% of Americans are hesitant or reticent, as in many other countries where vaccines are available. It is therefore important to have persuasive communication in order to obtain patient consent. American researchers (at the University of California Los Angeles, Carnegie Mellon University, Pittsburgh) have shown that encouraging people by all possible means, and to do so repeatedly, allows higher levels of vaccination to be reached.

The researchers analysed the results of a study based on reminder messages in favour of vaccination sent out to patients from a health centre. The first messages were sent the day after patients received their notification of eligibility for vaccination. A second message (first reminder) was sent a week later (on the 8^th day) to some patients, encouraging them to make an appointment to be vaccinated. Four types of this first reminder were sent: a non-personalised message with or without video (a link to an information video on COVID-19 and the effectiveness of vaccines) and a personalised message, with or without video.

14% of people who did not receive the reminder message were vaccinated within 6 days. After the first reminder, 17% of people having received the non-personalised message were vaccinated within 6 days, and 18% of those having received the personalised message (with or without video). Those people who were still not vaccinated after the second message received a third message. This allowed the number of people vaccinated within 4 weeks to be increased by 17%.

Communication strategies involving this type of message do therefore help to increase vaccination levels, and at very little cost. If similar messages were sent to the 263 million American adults, and if they reacted in the same way, that would lead to between 3 and 6 million extra vaccinations.