Impact of COVID-19 on routine childhood immunisations in low- and middle-income countries: A scoping review

Childhood vaccination trends during 2019 to 2022 in Tanzania and the impact of the COVID-19 pandemic

The COVID-19 pandemic has significantly disrupted healthcare systems at all levels globally, notably affecting routine healthcare services, such as childhood vaccination. This study examined the impact of these disruptions on routine childhood vaccination programmes in Tanzania. We conducted a longitudinal study over four years in five Tanzanian regions: Mwanza, Dar es Salaam, Mtwara, Arusha, and Dodoma. This study analyzed the trends in the use of six essential vaccines: Bacille Calmette-Guérin (BCG), bivalent Oral Polio Vaccine (bOPV), Diphtheria Tetanus Pertussis, Hepatitis-B and Hib (DTP-HepB-Hib), measles-rubella (MR), Pneumococcal Conjugate Vaccine (PCV), and Rota vaccines. We evaluated annual and monthly vaccination trends using time-series and regression analyses. Predictive modeling was performed using an autoregressive integrated moving average (ARIMA) model. A total of 32,602,734 vaccination events were recorded across the regions from 2019 to 2022. Despite declining vaccination rates in 2020, there was a notable rebound in 2021, indicating the resilience of Tanzania's immunization program. The analysis also highlighted regional differences in vaccination rates when standardized per 1000 people. Seasonal fluctuations were observed in monthly vaccination rates, with BCG showing the most stable trend. Predictive modeling of BCG indicated stable and increasing vaccination coverage by 2023. These findings underscore the robustness of Tanzania's childhood immunization infrastructure in overcoming the challenges posed by the COVID-19 pandemic, as indicated by the strong recovery of vaccination rates post-2020. We provide valuable insights into the dynamics of vaccination during a global health crisis and highlight the importance of sustained immunization efforts to maintain public health.

Impact of rotavirus vaccination in Malawi from 2012 to 2022 compared to model predictions

Rotarix® vaccine was introduced into the Malawi national immunization program in October 2012. We analyzed data on children <5 years old hospitalized with acute gastroenteritis from January 2012 to June 2022, and compared to pre-vaccination data from 1997 to 2009. We estimated vaccine coverage before, during, and after the COVID-19 pandemic using data from rotavirus-negative children. We compared the observed weekly number of rotavirus-associated gastroenteritis (RVGE) cases by age to predictions from a previously developed mathematical model to estimate overall vaccine effectiveness. The number of RVGE and rotavirus-negative acute gastroenteritis cases declined substantially following vaccine introduction. Vaccine coverage among rotavirus-negative controls was >90% with two doses by July 2014, and declined to a low of ~80% in October 2020 before returning to pre-pandemic levels by July 2021. Our models captured the post-vaccination trends in RVGE incidence. Comparing observed RVGE cases to the model-predicted incidence without vaccination, overall effectiveness was estimated to be modest at 36.0% (95% prediction interval: 33.6%, 39.9%), peaking in 2014, and was highest in infants (52.5%; 95% prediction interval: 50.1%, 54.9%). Our mathematical models provide a validated platform for assessing strategies to improve rotavirus vaccine impact in low-income settings.

Rubella epidemiology in Lesotho after vaccine introduction: a five-year review, 2018-2022

BACKGROUND

The rubella virus is a major contributor to birth defects globally and is preventable by vaccination. In 2020, the world was supposed to be free of both rubella and Congenital Rubella Syndrome (CRS) however this goal has yet to be realized with only 93 out of 194 WHO member states confirmed rubella-free in 2020.

METHODS

A retrospective measles and rubella case-based surveillance data record review was conducted from 2018 to 2022 to document rubella epidemiology after the introduction of rubella vaccination in Lesotho and progress toward elimination. All samples submitted for surveillance purposes and tested for rubella were considered but only filtered according to inclusion and exclusion criteria. Descriptive statistics were used to analyse the data.

RESULTS

Of the 1041 samples that were tested for rubella between 2018 and 2022, 10 (1%) were confirmed measles positive and were excluded from further analysis. The median age of the respondents was 6.0 (IQR 4.0-8.0.) years. About 643 (62.4%) of respondents were in the age category of 5 - <13 years. Rubella prevalence was 1% (95% CI; 0.5 -1.8%). The non-measles, non-rubella rash illness rate of 2 per 100 000 population was obtained at the national level each year of the study period but by only 2 of the country's 10 districts in 2021.

CONCLUSIONS

The study showed low rubella prevalence. Rubella infection was predominant in those aged 5 - < 13 years. Failure to meet surveillance targets at certain time points during the study period may have led to an underestimation of rubella cases. There is a need to improve the quality of measles and rubella surveillance in Lesotho. Supplementary immunization activities would also be useful in closing immunity gaps, limiting outbreaks, and advancing rubella and CRS elimination in Lesotho.

Changes in the medical admissions and mortality amongst children in four South African hospitals following the COVID-19 pandemic: A five-year review

Vulnerable children from poor communities with high HIV and Tuberculosis(TB) burdens were impacted by COVID-19 lockdowns. Concern was raised about the extent of this impact and anticipated post-pandemic surges in mortality. Interrupted time series segmented regression analyses were done using routinely collected facility-level data of children admitted for medical conditions at four South African referral hospitals. Monthly admission and mortality data over 60 months from 01 April 2018 to 31 January 2023 was analysed using models which included dummy lockdown level variables, a dummy post-COVID period variable, Fourier terms to account for seasonality, and excess mortality as a proxy for healthcare burden. Of the 45 015 admissions analysed, 1237(2·75%) demised with significant decreases in admissions during all the lockdown levels, with the most significant mean monthly decrease of 450(95%, CI = 657·3, -244·3) p<0·001 in level 5 (the most severe) lockdown. There was evidence of loss of seasonality on a six-month scale during the COVID periods for all admissions (p = 0·002), including under-one-year-olds (p = 0·034) and under-five-year-olds (p = 0·004). No decreases in mortality accompanied decreased admissions. Post-pandemic surges in admissions or mortality were not identified in children with acute gastroenteritis, acute pneumonia and severe acute malnutrition.During the COVID-19 pandemic, paediatric admissions in 4 hospitals serving communities with high levels of HIV, TB and poverty decreased, similar to global experiences; however, there was no change in in-hospital mortality. No post-pandemic surge in admissions or mortality was documented. Differences in the impact of pandemic control measures on the transmission of childhood infections and access to health care may account for differing outcomes seen in our setting compared to the global experiences. Further studies are needed to understand the impact of pandemic control measures on healthcare provision and transmission dynamics and to better inform future responses amongst vulnerable child populations.

Pertussis Epidemiology in Children: The Role of Maternal Immunization

In the last twelve months, a significant global increase in pertussis cases has been observed, particularly among infants under three months of age. This age group is at the highest risk for severe disease, hospitalization, and death. Maternal immunization with the Tdap vaccine during pregnancy has been recommended to protect newborns by transferring maternal antibodies transplacentally. This review examines the current epidemiology of pertussis, the importance of preventing it in young children, and the effectiveness of maternal immunization. Despite the proven benefits of maternal vaccination, which has been found effective in pertussis prevention in up to 90% of cases, coverage remains suboptimal in many countries. Factors contributing to low vaccination rates include vaccine hesitancy due to low trust in health authority assessments, safety concerns, practical barriers to vaccine access, and the impact of the COVID-19 pandemic, which disrupted routine vaccination services. The recent increase in pertussis cases may also be influenced by the natural cyclic nature of the disease, increased Bordetella pertussis (Bp) activity in older children and adults, and the genetic divergence of circulating Bp strains from vaccine antigens. Given the high efficacy of maternal vaccination in preventing pertussis in infants, increasing coverage rates is crucial. Efforts to improve vaccine uptake should address barriers to access and vaccine hesitancy, ensuring consistent immune protection for the youngest and most vulnerable populations. Enhanced maternal vaccination could significantly reduce the incidence of whooping cough in infants, decreasing related hospitalizations and deaths.

Strengthening health systems during non-pandemic period: Toward universal health coverage in the pandemic agreement

Reflecting the experiences of the COVID-19 pandemic, the global response was reviewed by the Independent Review Panel for Pandemic Preparedness and Response. Based on the panel reports, the World Health Organization (WHO) member states decided to establish the intergovernmental negotiating body for drafting a WHO convention, agreement or other international instrument on pandemic prevention, preparedness and response, aiming for approval at the 77th World Health Assembly in 2024 (May 27- June 1). Amidst this process, the National Center for Global Health and Medicine, Japan (NCGM), as a global health organization focusing on health system strengthening in low- and middle-income countries, from the perspective of Universal Health Coverage (UHC), provided technical inputs to the representatives of the Japanese government. This paper summarizes crucial aspects of the NCGM inputs, including maintaining essential health services delivery during a pandemic, responding to evolving demand of health workforce, and ensuring the equitable distribution of pandemic products. These aspects can contribute to not only strengthening health crisis response and preparedness, but also achieving UHC. Therefore, the concerted efforts focusing on UHC and health crisis could yield synergistic effects. In addition, another aspect stresses the importance of social protection systems beyond health sector to reach vulnerable populations experiencing hardships during the COVID-19 pandemic. Since the whole-of-government approach including social policies is covered in the draft pandemic agreement, it is hoped that the upcoming pandemic agreement will trigger each member state to expand the scope of health crisis management beyond the health sector.

The prioritisation of curable sexually transmitted infections among pregnant women in Zambia and Papua New Guinea: Qualitative insights

Curable sexually transmitted infections (STIs) are neglected in public health policy, services and society at large. Effective interventions are available for some STI but seem not to be prioritised at global, regional or local levels. Zambia and Papua New Guinea (PNG) have a high burden of STIs among pregnant women but little is known about the prioritisation of STI treatment and care among this group. We undertook a qualitative study to explore how STIs are prioritised among pregnant women in local health systems in Zambia and PNG. Semi-structured interviews were conducted with 19 key informants-health care workers providing antenatal care, and policy and programme advisers across the two countries. Audio recordings were transcribed and translated into English and stored, managed, and coded in NVivo v12. Analysis used deductive and inductive thematic analysis. Findings were coded against the World Health Organization health system building blocks. Participants spoke about the stigma of STIs at the community level. They described a broad understanding of morbidity associated with undiagnosed and untreated STIs in pregnant women. The importance of testing and treating STIs in pregnancy was well recognised but many spoke of constraints in providing these services due to stock outs of test kits for HIV and syphilis and antibiotics. In both settings, syndromic management remains the mainstay for treating curable STIs. Clinical practice and treatment were not in alignment with current STI guidelines in either country, with participants recognising the need for mentorship and in-service training, as well as the availability of commodities to support their clinical practice. Local disruptions to screening and management of syphilis, HIV and other curable STIs were widely reported in both countries. There is a need to galvanise priority at national and regional levels to ensure ongoing access to supplies needed to undertake STI testing and treatment.

Prevalence of stunting and its correlates among children under 5 in Afghanistan: the potential impact of basic and full vaccination

BACKGROUND

Child stunting is prevalent in low and middle-income countries (LMICs), but an information gap remains regarding its current prevalence, correlates, and the impact of vaccination against this condition in Afghanistan. This study aimed to determine the prevalence and correlates of moderate and severe stunting and the potential impact of basic and full vaccination among children under five in Afghanistan.

METHODS

This is a secondary analysis of the 2022-23 Afghanistan Multiple Indicators Cluster Survey (MICS) including 32,989 children under 5. Descriptive statistics were employed to describe the distribution of independent variables and the prevalence of stunting across them. Chi-square analysis was used to examine the association between each independent variable with stunting. Multinomial logistic regression was used to examine the risk of stunting across different independent variables.

RESULTS

A total of 32,989 children under 5 years old were included in this study. Of those 44.7% were stunted with 21.74% being severely stunted. Children aged 24-35 and 36-47 months faced the highest risk as compared to those aged 1-5 months. The prevalence was lower in female children and they were less likely to experience severe stunting. Stunting was more prevalent in rural areas, with children there 1.16 to 1.23 times more likely to be affected than urban counterparts. Lower wealth correlated with higher stunting. Younger maternal age at birth (≤ 18) correlated with increased stunting risks, particularly in severe cases. Parental education was inversely related to stunting; higher education levels in parents, especially fathers, were associated with lower stunting rates. Households with more than seven children showed a 25% and 44% higher risk of moderate and severe stunting, respectively, compared to families with 1-4 children. Improved sanitation, but not drinking water sources, was linked to reduced stunting in the adjusted model. Vaccination had a protective effect; in the adjusted analysis, basic and full vaccinations significantly lowered the risk of severe stunting by 46% and 41%, respectively.

CONCLUSION

In this nationally representative study, the prevalence of stunting was substantial (44.7%) in Afghan children. Additionally, the findings emphasize the critical factors associated with child stunting and underscore the protective role of vaccination against this condition, which provides policymakers with directions for policy efforts and intervention strategies to reduce child stunting in Afghanistan.

Impact of rotavirus vaccination in Malawi from 2012 to 2022 compared to model predictions before, during, and after the COVID-19 pandemic

Background

Rotarix® rotavirus vaccine was introduced into the Malawi national immunization program in October 2012. We used a previously developed mathematical models to estimate overall vaccine effectiveness over a 10-year period following rotavirus vaccine introduction.

Methods

We analyzed data on children <5 years old hospitalized with acute gastroenteritis in Blantyre, Malawi from January 2012 to June 2022, compared to pre-vaccination data. We estimated vaccine coverage before, during, and after the COVID-19 pandemic using data from rotavirus-negative children. We compared model predictions for the weekly number of rotavirus-associated gastroenteritis (RVGE) cases to the observed number by age to validate model predictions and estimate overall vaccine effectiveness.

Results

The number of RVGE and rotavirus-negative acute gastroenteritis cases declined substantially following vaccine introduction. Vaccine coverage among rotavirus-negative controls was >90% with two doses by July 2014, and declined to a low of ~80% in October 2020, before returning to pre-pandemic levels by July 2021. Our models captured the post-vaccination trends in RVGE incidence, with 5.4% to 19.4% of observed weekly RVGE cases falling outside of the 95% prediction intervals. Comparing observed RVGE cases to the model-predicted incidence without vaccination, overall vaccine effectiveness was estimated to be 36.0% (95% prediction interval: 33.6%, 39.9%) peaking in 2014 and was highest in infants (52.5%; 95% prediction interval: 50.1%, 54.9%).

Conclusions

Overall effectiveness of rotavirus vaccination in Malawi is modest despite high vaccine coverage and has plateaued since 2016. Our mathematical models provide a validated platform for assessing strategies to improve rotavirus vaccine impact.

The Impact of the Coronavirus Pandemic on Vaccination Coverage in Latin America and the Caribbean

BACKGROUND

Routine vaccination coverage in Latin America and the Caribbean declined prior to and during the coronavirus pandemic. We assessed the pandemic's impact on national coverage levels and analyzed whether financial and inequality indicators, immunization policies, and pandemic policies were associated with changes in national and regional coverage levels.

METHODOLOGY

We compared first- and third-dose coverage of diphtheria-pertussis-tetanus-containing vaccine (DTPcv) with predicted coverages using time series forecast modeling for 39 LAC countries and territories. Data were from the PAHO/WHO/UNICEF Joint Reporting Form. A secondary analysis of factors hypothesized to affect coverages during the pandemic was also performed.

RESULTS

In total, 31 of 39 countries and territories (79%) had greater-than-predicted declines in DTPcv1 and DTPcv3 coverage during the pandemic, with 9 and 12 of these, respectively, falling outside the 95% confidence interval. Within-country income inequality (i.e., Gini coefficient) was associated with significant declines in DTPcv1 coverage, and cross-country income inequality was associated with declines in DTPcv1 and DTPcv3 coverages. Observed absolute and relative inequality gaps in DTPcv1 and DTPcv3 coverage between extreme country quintiles of income inequality (i.e., Q1 vs. Q5) were accentuated in 2021, as compared with the 2019 observed and 2021 predicted values. We also observed a trend between school closures and greater-than-predicted declines in DTPcv3 coverage that approached statistical significance (p = 0.06).

CONCLUSION

The pandemic exposed vaccination inequities in LAC and significantly impacted coverage levels in many countries. New strategies are needed to reattain high coverage levels.

Status of Routine Immunization Coverage in the World Health Organization African Region Three Years into the COVID-19 Pandemic

Data from the WHO and UNICEF Estimates of National Immunization Coverage (WUENIC) 2022 revision were analyzed to assess the status of routine immunization in the WHO African Region disrupted by the COVID-19 pandemic. In 2022, coverage for the first and third doses of the diphtheria-tetanus-pertussis-containing vaccine (DTP1 and DTP3, respectively) and the first dose of the measles-containing vaccine (MCV1) in the region was estimated at 80%, 72% and 69%, respectively (all below the 2019 level). Only 13 of the 47 countries (28%) achieved the global target coverage of 90% or above with DTP3 in 2022. From 2019 to 2022, 28.7 million zero-dose children were recorded (19.0% of the target population). Ten countries in the region accounted for 80.3% of all zero-dose children, including the four most populated countries. Reported administrative coverage greater than WUENIC-reported coverage was found in 19 countries, highlighting routine immunization data quality issues. The WHO African Region has not yet recovered from COVID-19 disruptions to routine immunization. It is critical for governments to ensure that processes are in place to prioritize investments for restoring immunization services, catching up on the vaccination of zero-dose and under-vaccinated children and improving data quality.

The effects of COVID-19 on maternal, newborn and child health services in Papua New Guinea

Papua New Guinea's health system faces ongoing challenges in the provision of maternal and child health and has some of the poorest health indicators in the world. In this paper, we describe the impact of COVID-19 on maternal and child health, as examples of primary health care services. We conducted 131 semi-structured interviews with different population groups in seven provinces (Jul-Nov 2021). A deductive analysis focused on identifying the impact of COVID-19 using the World Health Organization building blocks framework. An inductive analysis explored these impacts for maternal and child health services specifically. We identified three broad themes: service disruption, challenges in access to care and service provision. Service disruption included the closure, suspension and relocation of services and workforce challenges due to healthcare worker absences, redeployment and working within an already constrained health system. Access to care was difficult due to lockdowns and restricted movement. Service provision continued despite the fear staff had of COVID-19. Investing in pandemic preparedness, including an adequately trained and resourced healthcare workforce and facilities able to withstand sustained provision of essential services should be integrated with locally appropriate, and timely community-based information to allay fears and mistrust within the healthcare system.