Global impact of mass vaccination campaigns on circulating type 2 vaccine-derived poliovirus outbreaks: an interrupted time-series analysis
File(s)
Published version
Author(s)
Type
Journal Article
Abstract
Background
Between 2016 and 2023, 3248 cases of circulating vaccine-derived type 2 poliomyelitis (cVDPV2) were reported globally and supplementary immunization activities (SIAs) with monovalent type 2 oral poliovirus vaccine (mOPV2) and novel type 2 oral poliovirus vaccine (nOPV2) targeted an estimated 356 and 525 million children, respectively. This analysis estimates the community-level impact of nOPV2 relative to mOPV2 SIAs.
Methods
We fitted interrupted time-series regressions to surveillance data between January 2016 and November 2023 to estimate the impact of nOPV2 and mOPV2 SIAs on cVDPV2 poliomyelitis incidence and prevalence in environmental surveillance across 37 countries, directly comparing the impact of SIAs in 13 countries where both vaccines were used.
Results
We did not find any statistically significant differences between nOPV2 and mOPV2 SIA impact except for in the Democratic Republic of Congo (DRC), where nOPV2 SIAs had lower impact (adjusted relative risk [aRR] for cVDPV2 poliomyelitis incidence per nOPV2 SIA, 0.505; 95% confidence interval [CI], .409–.623) compared to mOPV2 (aRR, 0.193; 95% CI, .137–.272); P value for difference in RRs = 3e-6.
Conclusions
We find variation in OPV2 SIA impacts globally, with greater certainty about Nigeria and DRC, where large outbreaks provided an opportunity to assess impact at scale. In most countries, we find no significant difference between nOPV2 and mOPV2 SIA impact. We are unable to identify the reason for the significant difference in DRC, which could include differential SIA coverage, timing, vaccine effectiveness, or outbreak dynamics.
Between 2016 and 2023, 3248 cases of circulating vaccine-derived type 2 poliomyelitis (cVDPV2) were reported globally and supplementary immunization activities (SIAs) with monovalent type 2 oral poliovirus vaccine (mOPV2) and novel type 2 oral poliovirus vaccine (nOPV2) targeted an estimated 356 and 525 million children, respectively. This analysis estimates the community-level impact of nOPV2 relative to mOPV2 SIAs.
Methods
We fitted interrupted time-series regressions to surveillance data between January 2016 and November 2023 to estimate the impact of nOPV2 and mOPV2 SIAs on cVDPV2 poliomyelitis incidence and prevalence in environmental surveillance across 37 countries, directly comparing the impact of SIAs in 13 countries where both vaccines were used.
Results
We did not find any statistically significant differences between nOPV2 and mOPV2 SIA impact except for in the Democratic Republic of Congo (DRC), where nOPV2 SIAs had lower impact (adjusted relative risk [aRR] for cVDPV2 poliomyelitis incidence per nOPV2 SIA, 0.505; 95% confidence interval [CI], .409–.623) compared to mOPV2 (aRR, 0.193; 95% CI, .137–.272); P value for difference in RRs = 3e-6.
Conclusions
We find variation in OPV2 SIA impacts globally, with greater certainty about Nigeria and DRC, where large outbreaks provided an opportunity to assess impact at scale. In most countries, we find no significant difference between nOPV2 and mOPV2 SIA impact. We are unable to identify the reason for the significant difference in DRC, which could include differential SIA coverage, timing, vaccine effectiveness, or outbreak dynamics.
Date Issued
2025-02-15
Date Acceptance
2025-01-01
Citation
Journal of Infectious Diseases, 2025, 231 (2), pp.e446-e455
ISSN
0022-1899
Publisher
Oxford University Press
Start Page
e446
End Page
e455
Journal / Book Title
Journal of Infectious Diseases
Volume
231
Issue
2
Copyright Statement
© The Author(s) 2025. Published by Oxford University Press on behalf of Infectious Diseases Society of America. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (https://creativecommons.org/licenses/by/4.0/), which permits unrestricted reuse, distribution, and reproduction in any medium, provided the original work is properly cited.
License URL
Identifier
https://www.ncbi.nlm.nih.gov/pubmed/39873524
PII: 7950519
Subjects
CHILDREN
COUNTRIES
EPIDEMIOLOGY
IMMUNOGENICITY
Immunology
INFANTS
Infectious Diseases
Life Sciences & Biomedicine
mass vaccination campaigns
Microbiology
POLIOMYELITIS
poliovirus
SAFETY
Science & Technology
surveillance
time-series analysis
vaccine
Publication Status
Published
Coverage Spatial
United States
Date Publish Online
2025-01-28