Peer-reviewed article
Association of vaccine stockout with immunisation coverage in low-income and middle-income countries: a retrospective cohort study
Donghoon Lee, Manuel Celestino Lavayen, Taeksoo Ted Kim, Ken E. Legins, Michelle Seidel ·
Summary
Written by AI, not yet AICS's view · claude-haiku-4-5-20251001This study examined whether vaccine shortages affect immunisation rates in low and middle-income countries between 2004 and 2019. Using data from 131 countries, researchers found that national-level stockouts of vaccines like DTP and measles were associated with 3.7 to 4 percentage point drops in vaccination coverage. While vaccine shortages clearly reduced the number of children vaccinated, the study did not find a clear link between these stockouts and infant or child mortality rates.
Key points
- Countries experiencing DTP vaccine stockouts had 3.7 percentage points lower DTP3 coverage compared to countries without stockouts
- Measles vaccine stockouts were associated with 4 percentage points lower MCV1 coverage
- BCG and OPV stockouts showed 2.4 and 2.6 percentage point coverage reductions respectively
- No statistically significant association was found between vaccine stockout frequency and infant or under-5 mortality rates
- Study covered 131 low-income and middle-income countries over 16 years (2004-2019)
Limitations
The study does not explain why stockouts did not translate to measurable increases in mortality, which may reflect time lags between coverage drops and mortality outcomes, or the impact of other health factors. The retrospective design cannot determine causation definitively or account for all confounding variables affecting mortality.
Abstract
OBJECTIVES: This study investigated the association between vaccine stockout and immunisation coverage, and infant/under 5 mortality rates. DESIGN: A retrospective cohort study. SETTING: Low-income and middle-income countries. PARTICIPANTS: A cohort of 131 low-income and middle-income countries from 2004 to 2019. PRIMARY OUTCOME MEASURES: Main outcomes included immunisation coverages of (1) diphtheria-tetanus-pertussis containing vaccine (DTP), (2) measles containing vaccine (MCV), (3) BCG and (4) oral polio vaccine (OPV). We also included infant and under 5 mortality rates as secondary outcomes. RESULTS: The countries that experienced national-level stockouts of DTP and MCV had 3.7 and 4 percentage points lower coverage rates of DTP3 and MCV1, respectively, compared with the countries without the stockout events (p<0.01). Moreover, the statistically significant differences in the immunisation coverage rates across the countries with and without the stockout events are 2.4 percentage points and 2.6 percentage points for BCG and OPV, respectively (p<0.01). CONCLUSION: Our findings show that the incidence of vaccine stockout events is associated with the decreased immunisation coverages for children in low-income and middle-income countries. However, we did not observe a statistically significant association between the increasing frequency of vaccine stockout and infant and under 5 mortality rates.
Findings the Hub has extracted
Each claim below is labelled by its type of design and links back to this report.
- Intervention
- Ensuring vaccine availability (measured by absence of national-level stockouts)
- Population
- Children in 131 low-income and middle-income countries, 2004-2019
Key finding
DTP stockouts associated with 3.7 percentage point lower DTP3 coverage (p<0.01)