Randomised controlled trials of behavioural nudges delivered through text messages to increase influenza and COVID-19 vaccine uptake among pregnant women (EPIC study) in Australia.

Publication date: Jul 09, 2025

Influenza and COVID-19 vaccine uptake among pregnant women is sub-optimal. We assessed the effectiveness of a multi-component behavioural nudge intervention to improve COVID-19 and influenza vaccine uptake among pregnant women. A ‘nudge’ was developed that comprised three SMS text message reminders with a social norming message, links to vaccine safety information, videos of health professionals and consumers recommending vaccination in pregnancy and a pledge to get vaccinated. In separate RCTs, pregnant women who had not received an influenza vaccine during the 2023 influenza season, or received ≤2 doses of a COVID-19 vaccine, were randomised (1:1) to standard care or intervention at four hospitals in Australia. A total of 1090 and 1068 pregnant women were randomised to the COVID-19 and influenza RCTs, respectively. The nudges resulted in a 1. 6 % increase in COVID-19 vaccine uptake and 1. 7 % increase in influenza vaccine uptake among pregnant women. However, there was no significant difference in the percentage of pregnant women in the intervention (2. 7 %) and the standard care (1. 1 %) groups receiving one dose of a COVID-19 vaccine from randomisation until delivery (odds ratio, 2. 40; 95 % confidence interval [CI], 0. 91 to 6. 30, P = 0. 08). Similarly, there was no significant difference in the percentage of pregnant women in the intervention (58. 0 %) and the standard care (56. 3 %) groups receiving the influenza vaccine from the time of randomisation until delivery (odds ratio, 1. 07; 95 % CI, 0. 84 to 1. 38, P = 0. 58). Less than 2 % of women had viewed the video content of the nudges in both RCTs. The nudges delivered via SMS resulted in small increases in COVID-19 and influenza vaccination uptake among pregnant women. Considering the very low cost of bulk SMS, these nudges may be cost-effective interventions at a population level.

Semantics

Original Article