How the COVID-19 pandemic affected routine child vaccination: an integrative review

Moré, Julia Stoeterau; Serbena, Daniel Rodrigo; Camargo, Luiz Gustavo Gusson de; Clemente, Pedro Augusto; Santos, Fernando Sluchensci dos; Bonini, Juliana Sartori

doi:10.31744/einstein_journal/2025RW1119

person Julia Stoeterau Moré

data collection · data analysis · and manuscript writing

school Laboratório de Neurociências e Comportamento, Universidade Estadual do Centro-Oeste, Guarapuava, PR, Brazil.

0009-0008-2616-0906

person Daniel Rodrigo Serbena

data collection · data analysis · and manuscript writing

school Laboratório de Neurociências e Comportamento, Universidade Estadual do Centro-Oeste, Guarapuava, PR, Brazil.

0000-0001-6885-5919

person Luiz Gustavo Gusson de Camargo

manuscript revision

school Laboratório de Neurociências e Comportamento, Universidade Estadual do Centro-Oeste, Guarapuava, PR, Brazil.

0000-0002-1770-4026

person Pedro Augusto Clemente

manuscript revision

school Laboratório de Neurociências e Comportamento, Universidade Estadual do Centro-Oeste, Guarapuava, PR, Brazil.

0000-0002-4116-076X

person Fernando Sluchensci dos Santos

manuscript revision

school Laboratório de Neurociências e Comportamento, Universidade Estadual do Centro-Oeste, Guarapuava, PR, Brazil.

0000-0001-7114-5264

person Juliana Sartori Bonini

study supervision

school Laboratório de Neurociências e Comportamento, Universidade Estadual do Centro-Oeste, Guarapuava, PR, Brazil.

0000-0001-5144-2253

personCorresponding author: Juliana Sartori Bonini Rua Alameda Élio Antonio Dalla Vecchia, 838 - Vila Carli Zip code: 85015-430 - Guarapuava, PR, Brazil Phone: (55 42) 99989-5666 E-mail:
juliana.bonini@gmail.com

Associate Editor:

Henrique Andrade Rodrigues da Fonseca Hospital Israelita Albert Einstein, São Paulo, SP, Brazil ORCID: https://orcid.org/0000-0001-8360-8465

Authors	Objective	Methodology	Type of study and number of articles	Regions studied	Results
Cardoso Pinto et al.⁽²⁰⁾	Summarize the reasons for interruptions in routine childhood immunizations in LMICs during the COVID-19 pandemic	A systematic review (PROSPERO CRD42021286 386) was carried out following the PRISMA 2020 guidelines	A total of thirteen studies were included describing the reasons behind the interruptions: 7 cross-sectional (quantitative), 5 qualitative and 1 mixed methods	LMICs In the cross-sectional studies, the WHO world region with the most respondents was Southeast Asia (49.9%). In qualitative studies, the majority of respondents were from the WHO African region (53.3%) or the Southeast Asia region (44.6%)	Seventeen reasons for interruptions were identified. The most common reasons for interruptions were parental fear of COVID-19 and avoidance of health services
Cardoso Pinto et al.⁽²¹⁾	Quantify the levels of interruption of routine immunization in LMICs	A systematic review (PROSPERO CRD42021286 386) of MEDLINE, Embase, Global Health, CINAHL and Scopus was conducted	A total of 39 cross-sectional studies were identified	The studies covered 6 WHO regions unevenly, with Africa (53.8%) being the most common	There was a decline in routine pediatric vaccination, higher in MICs and for vaccines administered at birth
Palo et al.⁽²²⁾	To study the use of maternal and child health (MCH) services during pandemics (Zika, Ebola and COVID-19) and the effectiveness of various interventions carried out to ensure the use of MCH services	A systematic and comprehensive search was carried out on MEDLINE/PubMed, Cochrane CENTRAL, Embase, Epistemonikos ScienceDirect, and Google Scholar	Out of 5.643 citations, 60 potential studies were finally included for analysis, 11 were qualitative, 8 were mixed methods, and 41 were quantitative	The studies included were from high-income countries (n = 23), LMICs (n = 34), and both (n = 3). Geographically, the included studies were widely distributed throughout the world	The findings suggest that during pandemics, the use of MCH care is often affected. Many innovative interventions have been adopted to ensure MCH services
Castrejon et al.⁽¹³⁾	Evaluate vaccination coverage data and identify recovery strategies for lost vaccines in selected Latin American countries (Argentina, Brazil, Chile, Colombia, Mexico, and Peru)	A systematic literature review of published articles was carried out to identify vaccination recovery strategies that were published	Of the 696 studies identified, 14 were included in this review	Argentina, Brazil, Chile, Colombia, Mexico and Peru	Overall coverage decreased to varying degrees among the countries investigated. This trend was observed before 2020, suggesting multifactorial reasons for the decline in vaccination rates in Latin America
Nimavat et al.⁽²³⁾	Understanding the challenges faced by India’s health system during a pandemic	The literature search for this review was carried out using PubMed, EMBASE, Scopus, Web of Science and Google Scholar	42 articles	India	The Indian health system was suffering even before the pandemic. The pandemic has stretched health services in India
Yunusa et al.⁽²⁴⁾	Understanding the international impact of the COVID-19 pandemic on routine vaccination of pregnant women and children aged 0-5 years	The authors conducted a systematic review of quantitative and mixed-methods studies exploring changes in vaccination coverage, vaccination services and vaccine confidence since the start of the COVID-19 pandemic	Thirty studies were included in the review; 2 studies were classified as descriptive analysis studies, 1 as an interim analysis, 8 as observational studies (including ecological, cross-sectional and cohort studies), and 2 as mixed-methods studies (1 descriptive and 1 cross-sectional analysis). 16 studies did not specify their type of study and therefore categorized as observational studies	Twenty studies focused on HICs (Japan, USA, Netherlands, Singapore, Canada, England, South Korea, Sweden, and Italy), and 7 focused on LMICs	Both groups experienced declines in vaccination coverage (up to - 79%), with greater disruptions in the accessibility and delivery of delivery of vaccination services reported within LMICs compared to HICs. The COVID-19 pandemic has resulted in a decrease in vaccination coverage and a reduction in vaccination routine services for pregnant women and babies
Wang et al.⁽⁴⁾	Systematically research and summarize the evidence from the literature reporting parents’ willingness/hesitation about vaccinating their children at the time of COVID-19 (in terms of childhood/routine vaccination, seasonal flu vaccination, human papillomavirus (HPV) vaccination and pneumococcal conjugate vaccination (PCV)	Academic articles were identified by searching the electronic databases PubMed, Web of Science (including SSCI and A&HI), EBSCOhost (including CINAL with Full Text, ERIC, MEDLINE, APA PsycArticles and APA PsycINFO) and Scopus (including published articles and pre-print services), covering the published periods of 1966-2022	A total of 20 eligible studies published from 2020-2022 were included for systematic summary by a thematic review, among which 12 studies were included in a meta-analysis conducted with R-.4.2.1	12 countries, including the United States, China, Saudi Arabia, Turkey, Switzerland, Indonesia, Mozambique, Albania, Canada, Israel, Japan and Spain	Based on the evidence provided by this review, it is necessary to design and implement parental intervention programs for the promotion of childhood vaccination targeting the specific local context/circumstances in different countries/regions
Lassi et al.⁽¹⁴⁾	Assess the impact on vaccine coverage worldwide and identify potential underlying factors	A systematic search strategy was employed in the PubMed, Embase, BioRxiv and COVID-19 databases of the WHO from December 2019 to September 15, 2020	A total of 17 observational studies were included	Of the 17 observational studies, 10 explored immunization campaigns in high-income countries (HICs) and the remaining 7 in LMICs. Of the HIC studies, 5 were carried out in the United States, 2 in the United Kingdom and 1 each in France, Italy and Spain. Of the LMICs, 4 were from Pakistan, 1 study was carried out in 2 countries, namely Afghanistan and Pakistan, and 1 was from South Africa and Sierra Leone	The results suggest that there has been a reduction in vaccination coverage and a decline in the number of vaccines administered, which led to children losing their vaccine doses
Spencer et al.⁽²⁵⁾	Assess evidence and evaluate the impact of the COVID-19 pandemic on inequalities in routine childhood vaccination coverage	The search strategy for published and pre-printed literature was conducted by a health sciences librarian at the University of Warwick Library (SJ) to identify published studies that reported data on inequality in routine childhood vaccination coverage during the COVID-19 pandemic. The review protocol was registered with PROSPERO (CRD 42021257431)	91 out of 1453 were selected for complete revision, and 13 fit into the selection criteria	The study did not specify the regions included. Only stated HICs and LMICs	The narrative synthesis found moderate evidence of inequality in the reduction of vaccination coverage of children during the COVID-19 lockdowns and moderately strong evidence of an increase in inequality compared to the pre-pandemic months (before March 2020)
SeyedAlinaghhi et al.⁽²⁶⁾	To systematically review studies that addressed the impacts of the COVID-19 pandemic on vaccination coverage in children and adolescents worldwide	Systematic search for relevant studies using the keywords in the PubMed, Web of Science and Cochrane databases	26 eligible studies	USA, Saudi Arabia, Japan, Brazil, Ethiopia, the Republic of Korea, Singapore, China, Morocco and Italy	Twenty-one studies showed a decrease in vaccination rates in children during the COVID-19 pandemic, whereas three studies found an increase or no significant change in vaccination only against influenza
Falope et al.⁽²⁷⁾	Describe studies that illustrate elements of health system resilience that have improved the ability of specific immunization programs to provide routine immunization services during the pandemic	A systematic search was carried out in Embase, Web of Science, PsychInfo and the gray literature between January 1, 2020, and November 12, 2021	The review of the full text led to the selection of 34 studies, which were included in the final review process	34 studies comprising 11 publications that included data from Asia, 10 that included data from America, 9 that included data from Europe, 5 that included data from South America and 4 publications that included data from Oceania	The studies indicated that there were immunization programs in all regions that demonstrated program resilience by using tools to mitigate the impact of the COVID-19 pandemic on routine immunizations
Dadari et al.⁽²⁸⁾	Summarize the routine setback in immunization after the COVID-19 pandemic and predictors of coverage and identify pro-equity strategies in urban and peri-urban settings through a systematic search of the published literature	Two databases, PubMed and Web of Science, were exhaustively searched using search terms and synonyms, resulting in 608 peer-reviewed articles identified	Based on the inclusion criteria, 15 articles were included in the final review	A total of 20 countries with the highest number of children who have received a zero dose and are home to >75% of these children in 2021 were prioritized	Several studies have clearly documented a decline in coverage in urban and peri-urban areas, with some predictors or challenges for optimal coverage, as well as some pro-equity strategies implemented or recommended in these studies
Kuznetsova et al.⁽²⁹⁾	Evaluate child vaccination programs implemented in selected countries	The review was carried out following the guidance issued by the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) and the Cochrane Handbook for Systematic Reviews of Interventions, including its technical supplements	A total of 466 full-text articles were assessed for eligibility, and 26 articles from seven countries were included in the synthesis	The review included studies from 7 countries: 7 studies on Italy, 4 on Germany, 3 on France, 4 on Latvia, 3 on Serbia, 3 on Moldova and 2 on Ukraine	Vaccination coverage for almost all vaccines improved significantly in Ukraine after the implementation of the mandate, despite the COVID-19 pandemic

	High-income countries	Low-income countries
Vaccine coverage	- The pandemic caused a reduction in operation hours and increased the duration of consultations. As an example, across the US, 61.7% of physicians offered reduced office hours for in-person visitations⁽²¹⁾ - Germany⁽²⁹⁾ showed a 7-fold decrease in measles cases, a 2.5-fold decrease in rubella cases, a 3-fold decrease in pertussis cases, a 2-fold decrease in Hib diseases, and a 2-fold decrease in varicella, which may be due to a mandatory vaccination law - In France,(¹⁴,²⁹) all mandatory priming doses and booster dispensations were reduced, especially in the first 4 weeks of the initial lockdown. Furthermore, along with Spain, it suffered major declines in vaccine deliveries, including MMR and HPV vaccines. England also showed a significant loss, but lower when compared to the first 2 countries - In Ukraine,(²⁹) there was a significant increase in vaccine coverage in 2020 compared to 2018 across Polio, DTP, HepB and Hib vaccines. Furthermore, in comparing 2020 to 2019, the incidence of measles fell by 215 times, mumps by 2.5 times, and rubella by 3.6 times - In Sweden(²⁴), a survey showed a significant portion of parents with increasing concerns surrounding the vaccination of their infant following the pandemic - South Korea(²⁴) maintained high vaccination rates during the COVID-19 pandemic through effective use of technology, including a national immunization registry and smartphone apps for scheduling and reminders. Its strong public health infrastructure, collaboration between private and public sectors, and innovative solutions like drive-through clinics ensured broad access to vaccines	- Median decline of −10.8% across all countries. Upper-middle-income countries and lower-MICs showed greater declines than low-income countries.(²¹) - Declines during the first 3 months of the pandemic were greater than during the remainder of 2020(²¹) - Africa(²⁰,²¹) presented mixed results across countries for DTP3 and MCV1 vaccination coverage - In Argentina, Brazil, Chile, Colombia, Mexico and Peru,(¹³) the change in vaccination coverage worsened in several vaccines (RV, MCV, PCV, pentavalent, BCG) - In India,(²³) it was estimated that about 27 million children missed diphtheria tetanus pertussis, which resulted in a 40% increase in mortality in 2021 - Within Brazil,(²⁸) Some of the states with substantial decline rates included Paraná (49.97%), São Paulo (43.25%), and regions such as the North (34.71%), Midwest (21.72%), South (63.50%), and Southeast (34.42%) - In Southeast Asia(²⁰) and the Western Pacific region, 79% of public sector vaccinations were disrupted, and 83% within the private sector
Particular reasons	- The most common reasons were fear of COVID-19 infection, transport challenges faced by both patient and healthcare workers, movement restrictions by lockdown, reduced operating hours and longer consultation times, cancellations and postponements of vaccinations appointments, booking appointments, unawareness of vaccination program’s continuation by parents, logistical problems including staff and equipment shortages, vaccine supply chain issues - Although quantitative studies attributed a bigger share of the blame to reduced healthcare-seeking, as opposed to healthcare-delivery issues, qualitative studies showcased an equal portion of the blame - Furthermore, in LMICs, barriers were mostly skewed towards vaccine inadequacy, vaccine hesitancy, and calling-off clinics. In HICs, fear of contracting COVID-19 and changes in management norms like shifting towards virtual consultations attributed to a decline in vaccine uptake
Other considerations	- In both categories of countries, rural areas suffered a higher drop in healthcare visits than urban areas - Studies agreed on an international inequity in pandemic effects on HIC and LMIC; however, these diverge when comparing different social strata classes - Both categories had the private sector as most affected when compared to the public one - Decreases in vaccine administrations between public and private sectors were primarily seen within HICs, whereas in LMICs, these differences in vaccine administrations by setting were typically reported between fixed and outreach services

[TFN1] HICs: high-income countries; LMICs: low- and middleincome countries.