Mass Vaccination: When and Why

Immunization prevents over 2-3 million deaths each year worldwide. In India, even though vaccines are offered free of cost at public health facilities the coverage remains low. Limited scrutiny has been conducted at health service and client interface for routine immunization (RI) services, which may have been affecting the acceptance of vaccines. This emphasizes the importance of assessing the level of satisfaction and perceived quality of clients regarding RI services. This study aimed to assess the perceived quality and level of overall general satisfaction with RI services of clients. In addition, determine the association of factors influencing clients perceived quality and overall general satisfaction with RI services. A community-based cross-sectional study was conducted in an urbanized village of Delhi from November 2015 to April 2017. A total of 279 RI visits were covered in the study, and the clients were interviewed at their residence using a pretested tool. The dissatisfaction toward the domains of perceived quality of RI services was reported to be 3.2% for vaccine availability, 9.7% for vaccine information, 3.2% for staff behavior, 6.1% for doctor behavior, and 7.5% for infrastructure. Multivariable-regression analysis indicated that distance to health facility, literacy and age of the client, doctor behavior, staff behavior, and infrastructure had an effect on overall general satisfaction of client toward RI services. The client's perception is multidimensional; improvement in one domain is likely to strengthen the other. By understanding the client's perspective toward quality of RI service, the health-care mangers may improve the level of overall satisfaction.

This study aimed to evaluate the utilization and quality of routine immunization (RI) services at a tertiary hospital during the second wave of the COVID-19 pandemic period. An observational analytical study was carried out in the Immunization Clinic of a tertiary hospital in Kathmandu, Nepal. The infant cohort was enrolled over a period of 4 months and followed up for a year (April 2021 to August 2022). Up-to-date immunization (UTD) status, overall and vaccine specific drop-out rates were quantified and reasons for missed or delayed doses were elicited from caregivers. An infant who received BCG, 3 doses of Pentavalent (DPT-HEPB-HIB) and OPV containing vaccine, one dose of fractional IPV, 2 doses of Rotavirus vaccine, 3 doses of PCV and first dose of Measles-Rubella (MR1) vaccine prior to their first birthday was categorized as UTD. Dropout rates between early and later vaccine doses were defined as the percentage of children that started their immunization series, but did not complete it for some reason. Among 227 infants (44.1% female) enrolled in the study, about three-fourths (74.5%, 95% CL 68.3% to 80.0%) were identified as UTD. Among UTD infants (n=169), two-thirds of the infants (65.1%, 95% CL 57.4% to 72.3%) had received the vaccines at the recommended age milestones. Overall dropout rate (BCG-MR1) was about 19% with highest dropout between the first and third Pentavalent dose (10%). Maximum delay was seen for MR1 vaccine. Common reasons for missed or delayed visits were that the infant received vaccine at another health facility, or the infant was ill, caregivers had travelled to village/maternal home or were busy. In conclusion, three-fourths of the infant cohort had received all of the recommended vaccines as per the National immunization schedule at our immunization clinic. However, one third had delayed their visits to the clinic. While routine immunization reporting looks at the number of vaccine doses that have been administered at an immunization clinic, this study has documented a sustained utilization of RI services during the second wave of the pandemic period. The lower dropout rate for pentavalent vaccine indicates a qualitative improvement in RI services at the tertiary hospital. However, an ongoing scrutiny of immunization data recording with a progression to digital health records and provision of timely reminders to caregivers may further help to strengthen RI services at the institutional level.

ObjectivesTo evaluate the cost effectiveness of the use of nine-valent pneumococcal polysaccharide conjugate vaccine in a routine infant immunisation programme based on the Pneumococcal Vaccine Trial (PVT) study in The Gambia.MethodsThis was a clinical trial-based cost-effectiveness study conducted as part of the PVT study. The PVT was an intention-to-treat double-blind placebo-controlled trial of a nine-valent pneumococcal polysaccharide conjugate vaccine. The trial was conducted in the eastern parts of The Gambia, West Africa and recruited 17 437 children aged 40–364 days. A deterministic static cohort model was developed to evaluate direct benefits and costs of pneumococcal conjugate vaccine in The Gambia's routine immunisation programme. The incremental cost-effectiveness ratio (iCER) is defined as vaccinating infants against pneumococcal disease compared with no vaccination from a public provider's perspective using The Gambia's 2005 projected under-one-year population.Key findingsThe results show the use of the vaccine in The Gambia's routine infant vaccination programme to be cost effective using an assumed price of US$5.00 per vial in single-dose vials. Compared with offering no vaccination, the incremental cost per DALYs averted would be 30 DALYs from the public provider perspective. At least 1569 and 340 invasive childhood pneumococcal illnesses and deaths respectively among the cohort would be prevented. In the absence of the vaccine 16 871 DALYs would be lost while with the use of the vaccine 7804 DALYs would be lost. Given the average treatment cost of pneumococcal illnesses to be US$191 (95% confidence interval 180 to 203) the introduction of the vaccine programme would lead to an additional cost of US$274 279 (about US$8.43/child).ConclusionsThe availability of a cost-effective vaccine that can prevent thousands of pneumococcal illnesses and related deaths is a major development towards improving the disease burden in sub-Saharan African countries. This study supports the introduction of nine-valent pneumococcal vaccine into the infant immunisation programme of The Gambia as it is cost effective and will avert many preventable deaths and illnesses. Despite differences in distribution of serotypes between countries, the static model used in the analysis makes the results applicable to other developing countries, particularly those in sub-Saharan Africa.

What is already known about this topic?The World Health Organization (WHO) varicella vaccines position paper states that countries where varicella is an important public health burden could consider introducing varicella vaccine (VarV) in the routine childhood immunization program (1). VarV has been available for many years in China but is not included in most routine immunization programs in China. As a result, substantial heterogeneity in vaccination coverage exists across regions. What is added by this report?In Beijing, adding a second dose of VarV for children and increasing coverage reduced the incidence of varicella. Lowering the age of the first dose of VarV to 12 months could further reduce varicella, especially among toddlers.What are the implications for public health practice?Governments should use economic analysis to consider inclusion of VarV into the routine children immunization program as a free vaccine and adopting a 2-dose schedule that starts at 12 months of age.

To evaluate the impact of the meningococcal A (MenA) vaccine introduction in Mali through mass campaigns on the routine immunization program and the wider health system. We used a mixed-methods case-study design, combining semi-structured interviews with 31 key informants, a survey among 18 health facilities, and analysis of routine health facility data on number of routine vaccinations and antenatal consultations before, during, and after the MenA vaccine campaign in December 2010. Survey and interview data were collected at the national level and in 2 regions in July and August 2011, with additional interviews in January 2012. Many health system functions were not affected-either positively or negatively-by the MenA vaccine introduction. The majority of effects were felt on the immunization program. Benefits included strengthened communication and social mobilization, surveillance, and provider skills. Drawbacks included the interruption of routine vaccination services in the majority of health facilities surveyed (67%). The average daily number of children receiving routine vaccinations was 79% to 87% lower during the 10-day campaign period than during other periods of the month. Antenatal care consultations were also reduced during the campaign period by 10% to 15%. Key informants argued that, with an average of 14 campaigns per year, mass campaigns would have a substantial cumulative negative effect on routine health services. Many also argued that the MenA campaign missed potential opportunities for health systems strengthening because integration with other health services was lacking. The MenA vaccine introduction interrupted routine vaccination and other health services. When introducing a new vaccine through a campaign, coverage of routine health services should be monitored alongside campaign vaccine coverage to highlight where and how long services are disrupted and to mitigate risks to routine services.

Background/Objectives: Varicella is a highly contagious childhood disease that may cause severe complications in susceptible populations. The SV-1 cell line-based varicella vaccine (VarV [SV-1]) has been increasingly used in routine immunization; however, safety and reporting patterns during the transition from partial use to full Expanded Program on Immunization (EPI) implementation remain poorly characterized. This study aimed to evaluate the safety profile and reporting dynamics of VarV (SV-1) before and after its incorporation into the Expanded Program on Immunization in Jiangsu Province, China. Methods: A retrospective observational study was conducted using data from the Jiangsu Provincial Immunization Integrated Service Management Information System and the Chinese National Adverse Event Following Immunization (AEFI) Information System (CNAEFIS), including all reported AEFI following VarV (SV-1) vaccination among children under 6 years of age during 2021-2023. Temporal trends, distribution characteristics, and factors associated with AEFI reporting were assessed using descriptive analyses, negative binomial (NB) regression models, and interrupted time series (ITS) analysis. Results: A total of 1,208,500 doses of VarV (SV-1) were administered, and 634 AEFI cases were reported, corresponding to an overall reporting rate of 52.46 per 100,000 doses. Most reported events were mild, self-limiting common reactions, predominantly pyrexia and injection-site reactions. No serious adverse events were identified. Although no immediate level change was observed at EPI implementation, a significant increasing post-EPI trend was detected, consistent with enhanced surveillance sensitivity rather than a change in intrinsic vaccine safety. Abnormal reactions were rare and resolved without sequelae. Conclusions: AEFI reporting rates following VarV (SV-1) vaccination in Jiangsu Province were within expected ranges, predominantly mild and reversible. Findings support the favorable safety profile of the VarV (SV-1) in routine childhood immunization programs and provide real-world evidence to support continued implementation of the two-dose varicella vaccination strategy within the EPI.

The COVID-19 epidemic has significantly disrupted routine childhood immunization programs. This study assesses the impact of different COVID-19 prevalence phases on immunization coverage and timeliness in Shanghai, China. We employed a retrospective cohort design, encompassing children born between September 1, 2018, and August 30, 2023. Children were categorized into three COVID-19 phases based on their expected vaccination dates: baseline period, epidemic period, and pre/post-epidemic period. Kaplan-Meier estimators were utilized to ascertain the cumulative vaccination probabilities, with differences tested using the log-rank method. A multivariate Cox proportional hazards model was conducted to assess the impact of COVID-19 phases on vaccination timeliness. Vaccination timeliness significantly declined when the vaccination window coincided with an epidemic period, particularly for older children and during heightened epidemic activity. The probability of timely vaccination at 2 months was 0.89 (95% CI: 0.86–0.92) in the baseline period and 0.53 (95% CI: 0.51–0.55) in the epidemic period, compared to the pre/post-epidemic period. At 3 months, the probability of timely vaccination decreased 12% (HR = 0.88, 95% CI 0.86–0.90) and 49% (HR = 0.51, 95% CI 0.49–0.53), respectively. Similarly, for vaccinations scheduled at 4 months, the probabilities of timely vaccination were 0.87 (95% CI 0.85–0.89) and 0.49 (95% CI 0.47–0.51) times. At 5 months, the probabilities declined 9% (HR = 0.91, 95% CI 0.87–0.94) and 57% (HR = 0.43, 95% CI 0.40–0.46), correspondingly. Our study assessed the notable decline of vaccination timeliness during epidemic periods, highlighting the need for targeted strategies to mitigate disruptions in routine childhood immunization services.

The case for vaccinating against meningitis B

Introduction: The COVID-19 pandemic resulted in movement and service restrictions during 2020 and 2021 that may have affected the essential immunization services in Sierra Leone. We analyzed the national routine immunization (RI) data to assess the effect of the COVID-19 pandemic in immunization coverage. Methods: Using national RI data for the period 2018 to 2021, we computed vaccination coverages for pentavalent vaccine (Penta1 and Penta3), first and second doses of measles-rubella (MR1 & MR2). We also computed the dropout rates (DOR) for the same antigens. A coverage of ≥90% and a DOR of <10% were considered good performance. The pre COVID-19 period for this study was 2018 to 2019, while the COVID-19 period was 2020 to 2021. Results: Penta1 and Penta3 coverages increased from 93.9% and 90.6% in 2018 to 96.2%, and 96.2% in 2019, respectively. Although there was a slight decrease from 2019 to 2020, the coverage reduction from 2020 to 2021 was higher with Penta1 and Penta3 coverages decreasing from 93.3% and 91.3% in 2020 to 75.5% and 74. 4% in 2021, respectively. The MR1 coverage target was achieved in 2019 at 93.8% but failed to meet the MR2 target coverage from 2018 to 2021. Ten of the 16 districts achieved the 90% target for Penta3 coverage before the COVID-19 pandemic, but only four districts achieved the target since the COVID-19 pandemic. The dropout rate for Pentavalent was within the target throughout the study period, while measles dropout rate exceeded the target of less than 10% throughout the study period. Conclusion: RI gains in the pre-COVID-19 era were lost during the COVID-19 era, resulting in a negative impact on routine EPI services in Sierra Leone. We recommend that the EPI program strengthen vaccination indicators and increase community awareness on the importance, availability, and timeliness of immunization activities Keywords: COVID-19, routine immunization, immunization coverage, pentavalent, measles-rubella, Sierra Leone

Background: Despite global progress in immunization, Nigeria continues to face challenges in achieving adequate vaccination coverage. This study examined the knowledge and practices of primary healthcare workers regarding routine childhood immunization in Osun State, where coverage exceeds national averages but remains below global targets. Methods: A descriptive cross-sectional study was conducted among 273 primary healthcare workers across 48 primary health centers in Osun State. Results: There was a significant disparity between the knowledge (86.5%) and practice of routine childhood immunization (40.6%). Key gaps included inadequate vaccine storage (with 59% failing to maintain temperature records) and inconsistent caregiver communication (only 53.7% consistently obtained consent). Training deficiencies were evident, with 12.3% of staff lacking pre-service immunization training and 60% not having received refresher training within the previous six months. Conclusions: These findings suggest that achieving better immunization outcomes requires more than just knowledge transfer. Health system strengthening should focus on improving cold chain infrastructure, implementing regular competency-based training, and strengthening supervision mechanisms. The study emphasizes the importance of ongoing support for healthcare workers to bridge the gap between knowledge and practice in routine immunization services.

Hepatitis B virus (HBV) is endemic in the Kingdom of Saudi Arabia. To prevent the chronic carriage of HBV in Saudi children, hepatitis B vaccine was added as the seventh immunogen in the expanded program on immunization (EPI). In the first year, the coverage of the first dose and third dose of HB vaccine was 90% and 73%, respectively. In a survey of 637 children, 603 (95%) were positive for antibody to hepatitis surface antigen (anti-HBs) without concomintant antibody to hepatitis B core antigen (anti-HBc) or hepatitis B surface antigen (HBsAg). A total of 592 (93%) with anti-HBs titer of > 10 IU/L were considered as responders to the vaccine. The majority (60%) of these responders had titers > 100 IU/L. Only one (0.3%) non-responder was positive for anti-HBc alone. Using historical control, the protective efficacy was estimated as 99%. Neither the gender of the recipient, schedule of the vaccination, nor the sourve of vaccine influenced the response to the vaccine. The successful integration of the HB vaccine into the EPI was due to the effectiveness of the EPI and the efficient primary health care system in Saudi Arabia.

IntroductionMeasles is an acute viral disease that remains endemic in much of sub-Sahara Africa, including Liberia. The 2014 Ebola epidemic disrupted an already fragile health system contributing to low uptake of immunization services, population immunity remained low thus facilitating recurrent outbreaks of measles in Liberia. We describe lessons learnt from detecting and responding to recurrent outbreaks of measles two years post the 2014 Ebola epidemic in Liberia.MethodsWe conducted a descriptive study using the findings from Integrated Diseases Surveillance and Response (IDSR) 15 counties, National Public Health Institute of Liberia (NPHIL), National Public Health Reference Laboratory (NPHRL) and District Health Information Software (DIHS2) data conducted from October to December, 2017. We perused the outbreaks line lists and other key documents submitted by the counties to the national level from January 2016 to December 2017.ResultsFrom January 2016 to December 2017, 2,954 suspected cases of measles were reported through IDSR. Four hundred sixty-seven (467) were laboratory confirmed (IgM-positive), 776 epidemiologically linked, 574 clinically confirmed, and 1,137 discarded (IgM-negative). Nine deaths out of 1817 cases were reported, a case fatality rate of 0.5%; 49% were children below the age of 5 years. Twenty-two percent (405/1817) of the confirmed cases were vaccinated while the vaccination status of 55% (994/1817) was unknown.ConclusionRevitalization of IDSR contributed to increased detection and reporting of suspected cases of measles thus facilitating early identification and response to outbreaks. Priority needs to be given to increasing the uptake of routine immunization services, introducing a second dose of measles vaccine in the routine immunization program and conducting a high-quality supplementary measles immunization campaign for age group 1 to 10 years to provide protection for a huge cohort of susceptible.

Introduction: Supportive supervision is crucial for enhancing healthcare quality by improving internal relationships, resolving issues, and optimizing resources. Recent evidence from India shows it enhances immunization coverage and strengthens the local health system. Objective: To evaluate routine immunization services in terms of input and process through supportive supervision and compare service delivery between two quarters.Method: This cross-sectional study, conducted between July 2021 and February 2022, assessed the delivery of routine immunization services by frontline workers (FLWs) within Village Health Sanitation and Nutrition Day (VHSND) sessions in Assam. Five districts were selected to represent each zone of the state. Micro-plans for VHSND sessions were reviewed to visit 25-30 sessions per district based on operational feasibility. Data collected by district coordinators using a standardized checklist assessed logistics and service delivery. Statistical analysis included quarterly group comparisons using Chi-square and Fisher's exact tests (p < 0.05 significance). The findings were shared in district-level review meetings to facilitate corrective actions by all stakeholders.Results: A total of 140 VHSND sites were assessed. Paracetamol was available at 123 sites (87.9%), and updated due list was present at 120 sites (85.7%). However, Vitamin A was available at 26 sites (18.6%), ORS and Zinc were at 11 sites (7.9%) and 14 sites (10.0%), respectively. The presence of Anganwadi Workers (AWWs) at VHSND sites increased significantly from 61.2% in the first quarter to 76.7% in the second quarter (p = 0.04). Adherence to micro plans among Accredited Social Health Activists (ASHAs) was high, rising from 97.0% in the first quarter to 100% in the second quarter. Record-keeping also improved, with headcount survey documentation increasing from 83.6% in the first quarter to 95.9% in the second quarter (p = 0.01). Conclusion: The study highlighted improvements in logistics, documentation, and ASHA performance under supportive supervision. Continued focus on essential supplies and educational materials, alongside effective supervision and further research, is crucial for enhancing child health outcomes.

Background.The Basic Package of Health Services (BPHS) program has increased access to immunization services for children living in rural Afghanistan. However, multiple surveys have indicated persistent immunization coverage gaps. Hence, to identify gaps in implementation, an assessment of the BPHS program was undertaken, with specific focus on the routine immunization (RI) component.Methods.A cross-sectional survey was conducted in 2014 on a representative sample drawn from a sampling frame of 1858 BPHS health facilities. Basic descriptive analysis was performed, capturing general characteristics of survey respondents and assessing specific RI components, and χ2 tests were used to evaluate possible differences in service delivery by type of health facility.Results.Of 447 survey respondents, 27% were health subcenters (HSCs), 30% were basic health centers, 32% were comprehensive health centers, and 12% were district hospitals. Eighty-seven percent of all respondents offered RI services, though only 61% of HSCs did so. Compared with other facility types, HSCs were less likely to have adequate stock of vaccines, essential cold-chain equipment, or proper documentation of vaccination activities.Conclusions.There is an urgent need to address manpower and infrastructural deficits in RI service delivery through the BPHS program, especially at the HSC level.

IntroductionThe COVID-19 pandemic disrupted healthcare provision and access in sub-Saharan Africa. Lockdowns and travel restrictions, coupled with fear of contracting the virus, disrupted services, especially for women’s and children’s health,...