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. 2021 Oct 22;9(11):1228.
doi: 10.3390/vaccines9111228.

Impact of COVID-19 Disruptions on Global BCG Coverage and Paediatric TB Mortality: A Modelling Study

Nabila Shaikh  1 , Puck T Pelzer  2 , Sanne M Thysen  3   4 , Partho Roy  5 , Rebecca C Harris  1   6 , Richard G White  1
Affiliations

Impact of COVID-19 Disruptions on Global BCG Coverage and Paediatric TB Mortality: A Modelling Study

Nabila Shaikh et al. Vaccines (Basel). .

Abstract

The impact of COVID-19 disruptions on global Bacillus Calmette-Guérin (BCG) coverage and paediatric tuberculosis (TB) mortality is still unknown. To fill this evidence-gap and guide mitigation measures, we estimated the impact of COVID-19 disruptions on global BCG coverage and paediatric TB mortality. First, we used data from multiple sources to estimate COVID-19-disrupted BCG vaccination coverage. Second, using a static mathematical model, we estimated the number of additional paediatric TB deaths in the first 15 years of life due to delayed/missed vaccinations in 14 scenarios-varying in duration of disruption, and magnitude and timing of catch-up. We estimated a 25% reduction in global BCG coverage within the disruption period. The best-case scenario (3-month disruption, 100% catch-up within 3 months) resulted in an additional 886 (0.5%) paediatric TB deaths, and the worst-case scenario (6-month disruption with no catch-up) resulted in an additional 33,074 (17%) deaths. The magnitude of catch-up was found to be the most influential variable in minimising excess paediatric TB mortality. Our results show that ensuring catch-up vaccination of missed children is a critical priority, and delivery of BCG alongside other routine vaccines may be a feasible way to achieve catch-up. Urgent action is required to support countries with recovering vaccination coverages to minimise paediatric deaths.

Keywords: BCG; COVID-19; immunization; mathematical model; paediatric mortality; tuberculosis.

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Conflict of interest statement

R.C.H. reports current employment at Sanofi Pasteur, her Sanofi employment includes work on COVID-19, but is unrelated to TB.

Figures

Figure 1
Figure 1
Vaccine coverage scenarios by age in weeks compared to baseline of no disruption; (A) Scenarios A1 to A7 e.g., disruption for 3 months; (B) Scenarios B1 to B7 e.g., disruption for 6 months.
Figure 2
Figure 2
Additional paediatric tuberculosis (TB) deaths from 14 scenarios compared to a baseline of no disruption.
See this image and copyright information in PMC

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