'Prevention is better than cure': a mixed methods study of communities' and healthcare workers' perspectives on new adult and adolescent TB vaccines and their implementation in Zambia.

BACKGROUND

New tuberculosis (TB) vaccines for adults and adolescents are crucial for achieving global control targets, and several candidates may be ready for introduction within 5 years. We conducted a convergent mixed-methods study in Lusaka, Zambia, among community members and healthcare workers (HCWs) to understand preliminary TB vaccine acceptance and potential factors influencing uptake to inform readiness activities critical for successful implementation.

METHODS

Adult community members were enrolled from randomly selected households within four communities with historically low COVID-19 vaccine coverage, and HCWs from 10 public healthcare facilities representing different care levels. Structured surveys evaluated participants' perspectives on new vaccines and mixed-effects Poisson regression was used to estimate the marginal probability of participants' intention to get a new TB vaccine. Qualitative in-depth interviews (IDIs; n=24) and focus group discussions (FGDs; n=9) were conducted and analysed using a hybrid approach to explore acceptable vaccine attributes, preferences and determinants of TB vaccine uptake and recommendations for rollout.

RESULTS

Overall, 499 participants completed surveys (395 community members and 104 HCWs) with 62 additional participants across IDIs and FGDs. 77% of community members and 83% of HCWs expressed intention to get a TB vaccine. Perceived TB risk and severity concerns were the only significant drivers of vaccine intention. Participants pragmatically accepted the WHO's preferred vaccine specifications (50% efficacy, two-dose schedule, transient, mild side effects, at least 2 years' duration) though HCWs preferred higher efficacy thresholds due to occupational risk. Implementation preferences emphasised early community engagement (at least 3-6 months pre-rollout), diverse delivery approaches, including facility-based and community venues for adults, schools for adolescents and door-to-door campaigns, while addressing COVID-19-related scepticism through transparent, clear communication using trusted sources.

CONCLUSIONS

This study reveals strong potential for a successful TB vaccine rollout in Zambia through proactive implementation strategies, including early community engagement, transparent communication and person-centred delivery approaches.