We conducted a mixed methods study on willingness to receive a new TB vaccine among the target population for new vaccines (i.e., adults and adolescents) and caregivers of adolescents in southern Mozambique. We found an overall high proportion of willingness to receive a new TB vaccine (77%), which anticipates moderate to high uptake of a TB vaccine in this setting.¹⁷ We now report that adolescents were more willing to receive a new TB vaccine than adults even when adjusting for other factors which may influence vaccination decisions. Through in-depth interviews which further explored the preferences expressed in survey responses and largely corroborated the quantitative findings from surveys, we found that participants expressing uncertainty about vaccination would require more information about how a new vaccine would work and why it is being recommended to them. However, most felt that if a vaccine was shown to prevent TB, they would be willing to receive it. Healthcare workers, government agencies, and community leaders were cited as trusted voices of information about a new TB vaccine, with social media as relatively less important in influencing vaccination decisions.

This is the first study of which we are aware to explore community perceptions of new TB vaccines, so there is little prior data on this topic to which to compare our findings. However, we note that acceptability and uptake of another preventive intervention against TB, drug therapy to prevent the progression of Mtb infection to TB (i.e., TB preventive therapy, or TPT), is generally low compared to our estimates of willingness to receive a TB vaccine. Estimates of TPT uptake in South Africa are approximately 50% among persons in whom it is indicated, compared to 77% of respondents in our study who responded that they would receive a new TB vaccine if available.¹⁸ If a TB vaccine for adolescents and adults is approved, understanding different attitudes towards these two preventive interventions can set expectations about the uptake of each in different settings and population groups. Despite apparently higher acceptability than TPT, willingness to receive a TB vaccine in our study was lower than for other new vaccines. A systematic review of malaria vaccine acceptance studies found 95% acceptability in surveys completed prior to vaccine introduction in malaria-endemic countries.¹⁹

We found several factors associated with willingness to be vaccinated. Willingness to be vaccinated was associated with greater knowledge of TB, suggesting that a basic level of knowledge about the disease is key to understanding the need for a vaccine. Relatedly, persons who knew someone with TB were also more willing to be vaccinated and, in interviews, expressed the importance of preventive interventions against TB. These findings suggest that general health education about TB (on its symptoms, treatment, and transmission) in conjunction with information about a new vaccine could facilitate high uptake in this setting. Adults were generally more skeptical of vaccines than were adolescents, especially adult men. Given the higher burden of TB among adult men, and their disproportionate contribution to Mtb transmission, vaccine outreach will be a particularly important for this group. Women expressed more uncertainty about vaccination than men, expressing a need for more information prior to making a decision about vaccination, again underscoring the need to clearly communicate about the key features of and need for a new adolescent and adult TB vaccine, given that there is an existing vaccine for TB (BCG). Additional studies should continue to characterize reasons for TB vaccine hesitancy that may result in lower levels of acceptance for a new TB vaccine to understand ways to remove barriers to vaccine uptake and to design tailored communication strategies that address specific community concerns about vaccination. In this area of southern Mozambique, we found that healthcare providers, government agencies (i.e., the Ministry of Health), and community leaders were trusted sources of vaccine information. Provider recommendation is a well-documented strategy for increasing uptake of other vaccines²⁰ and may be an important strategy for maximizing uptake of new TB vaccines. Social media was not considered a trusted source of information, though the reach of these platforms is still low in Mozambique (<12% of the population in early 2025 uses Facebook).²¹ Understanding the most credible sources of vaccine information can guide decisions about the platforms of communication campaigns suitable for different settings and population subgroups. Work to understand optimal communication strategies will be particularly important given that there are few other vaccines in Mozambique with broad indications in adolescents and adults; the methods for effectively reaching this group may be different from those typically used to encourage childhood vaccination. Recent immunization campaigns in this age group for HPV and SARS-CoV-2 vaccines have been successful^22,23 and may be a useful template for new TB vaccines.

There were two surprising findings that merit additional research. We found that adults who reported previous issues accessing vaccines were more likely to receive a new TB vaccine. While we think this may reflect high motivation to be vaccinated, combined with the recent memory of limited supply of SARS-CoV-2 vaccines in Mozambique, this dynamic should be explored in future studies. In addition, adults who reported high perceived risk of TB were less likely to be vaccinated than those who perceived themselves at moderate risk of TB. While these trends were not statistically significant, we consider this an area where additional qualitative work may explain these attitudes and offer further insights to facilitate vaccine uptake.

Our study has several limitations. First, this was a small study (n=241) recruited using purposive sampling. Our study population over-represents women (68%) and individuals with past TB (56%). It should not be considered representative of Mozambique nationally, or of other countries, since attitudes towards vaccines are known to vary significantly by setting. Second, we encountered difficulties with eliciting rich interview responses from adolescents, especially adolescent males. (Many responses were short in duration and lacking in depth.) We used the interview findings to substantiate and elaborate on results from the quantitative analysis rather than conduct a standalone qualitative analysis, in part because of the sparse responses given by adolescents. More work should be done among adolescents to understand attitudes towards a new TB vaccine, as this period represents a time of increasing TB exposure risk and therefore a key population group for ensuring high coverage of preventive interventions. Moreover, since we collected qualitative and quantitative data collection simultaneously, emergent findings in the qualitative data could not be explored quantitatively (and vice versa). Future mixed methods work will be useful to more fully explore attitudes around new TB vaccines in this setting. Finally, we acknowledge that willingness to be vaccinated may not necessarily translate into a decision to vaccinate, and therefore these estimates should not be interpreted as expectations of vaccine coverage. However, these data remain important for understanding potential uptake, anticipating barriers to high coverage in this setting, and suggesting avenues for vaccine outreach to plan for the eventual introduction of an adolescent and adult TB vaccine.

In summary, our study reports high willingness to receive a new TB vaccine among adolescents and adults, with adolescents especially willing to receive a new TB vaccine. Personal experience with TB and greater knowledge of the disease was linked with willingness to be vaccinated. Qualitative findings largely reinforced quantitative findings, further clarifying that even among those who expressed hesitancy, a safe and effective TB vaccine that is endorsed by healthcare workers, government agencies, and community leaders would likely have high uptake. Our findings are specific to southern Mozambique and can shape vaccine introduction efforts after a TB vaccine is licensed and approved for use in this age group.