News release

From: BMJ Group

Extend vaccination opportunities and involve community members in communicating about vaccines to boost uptake, say researchers

Findings highlight the most effective components across different populations and contexts

Extending vaccination opportunities, involving community members alongside healthcare professionals in communicating about vaccines, and providing financial incentives are among the most effective ways to increase vaccine uptake, finds an analysis of international trial evidence published by The BMJ today.

The researchers say the findings are important for designing, optimising, and implementing targeted interventions to increase vaccine uptake, as they highlight the most effective components across different populations and contexts.

The global decline in vaccine uptake, alongside a rise in preventable disease outbreaks, highlights the urgent need to pinpoint and close gaps in vaccine coverage. Yet no existing reviews assess the effectiveness of individual intervention components across different populations and contexts.

To address this, researchers conducted a component-level analysis of 237 randomised controlled trials in high and upper middle income countries. Their aim was to compare the effectiveness of different content and delivery components of vaccine uptake interventions for all vaccines on the UK schedule and across all age groups.

The 237 trials involved 4,361,717 participants (40% male). Of these, 110 trials were at low risk of bias, 96 had some concerns, and 31 were at high risk.

The results show that for children’s vaccination, offering payments to cover costs (eg, travel costs) and decision aids were beneficial, while extended vaccination opportunities and information about social factors (eg, acting for the benefit of society) might also increase uptake.

For adolescents and young adults, beneficial effects were shown for personal delivery formats (eg, calls, texts, emails), delivery by community members alongside healthcare professionals, and social factors. There was evidence of a negative effect of decision aids and some evidence of a negative effect of human versus non-human interaction.

For adults, human interaction, extended vaccination opportunities, appointment scheduling help, payments to cover costs, and motivational interviewing to encourage uptake were beneficial. Financial incentives and information on vaccine safety and effectiveness showed some evidence of benefit, while non-human interaction showed a negative effect versus no interaction.

In underserved communities who often face social, economic, and geographical barriers to care, extended vaccination opportunities, financial incentives, and providing reminders increased uptake. The effectiveness of certain components may also have been influenced by the covid-19 pandemic.

This large study, using complex analyses across diverse interventions and vaccines, provides widely generalisable findings, say the researchers, but they also acknowledge some limitations, such as limited data for some intervention components and two-thirds of the trials being US-based.

They suggest integrating these findings with local level data to guide the implementation of effective intervention combinations, and say that consideration of cost and cost-effectiveness data “will further inform decision making around which interventions to implement given limited resources.”