The potential impact of new tuberculosis vaccines on the burden of tuberculosis in people with HIV in South Africa.

BACKGROUND: People with HIV (PWH) are at an increased risk of tuberculosis (TB). New TB vaccines may help reduce this burden. New TB vaccine candidates are well tolerated and immunogenic in PWH. There are currently limited data on vaccine efficacy in this population. METHODS: Using mathematical modeling, we explored the potential impact of a novel TB vaccine on TB burden in PWH in South Africa between 2030 and 2050. We compared the impact of a vaccine delivered irrespective of HIV status to vaccination of either PWH or people without HIV. We explored the impact of reduced vaccine efficacy and duration of protection in PWH relative to people without HIV on our model predictions. RESULTS: Vaccination irrespective of HIV status, with a vaccine with equal efficacy and duration in PWH, could avert up to 1.01 (95% range: 0.96-1.22) million TB cases in PWH. Restricting vaccination to PWH or people without HIV would achieve 65% (60-70) and 48% (46-53) of the total impact, respectively. These results are strongly dependent on the assumed efficacy and duration of protection in PWH. Further information on these characteristics is important to identify the most efficient use of new vaccines to reduce TB burden in PWH. CONCLUSION: Our results suggest that new vaccines could play an important role in reducing the TB burden in PWH. Vaccines targeted at people without HIV could provide significant indirect benefit to PWH, but vaccines which are well tolerated and effective in PWH will be critical to maximizing the impact in this population.