Expanded Program On Immunization Research Articles

Contribution of vaccination to improved survival and health: modelling 50 years of the Expanded Programme on Immunization

WHO, as requested by its member states, launched the Expanded Programme on Immunization (EPI) in 1974 to make life-saving vaccines available to all globally. To mark the 50-year anniversary of EPI, we sought to quantify the public health impact of vaccination globally since the programme's inception. In this modelling study, we used a suite of mathematical and statistical models to estimate the global and regional public health impact of 50 years of vaccination against 14 pathogens in EPI. For the modelled pathogens, we considered coverage of all routine and supplementary vaccines delivered since 1974 and estimated the mortality and morbidity averted for each age cohort relative to a hypothetical scenario of no historical vaccination. We then used these modelled outcomes to estimate the contribution of vaccination to globally declining infant and child mortality rates over this period. Since 1974, vaccination has averted 154 million deaths, including 146 million among children younger than 5 years of whom 101 million were infants younger than 1 year. For every death averted, 66 years of full health were gained on average, translating to 10·2 billion years of full health gained. We estimate that vaccination has accounted for 40% of the observed decline in global infant mortality, 52% in the African region. In 2024, a child younger than 10 years is 40% more likely to survive to their next birthday relative to a hypothetical scenario of no historical vaccination. Increased survival probability is observed even well into late adulthood. Since 1974 substantial gains in childhood survival have occurred in every global region. We estimate that EPI has provided the single greatest contribution to improved infant survival over the past 50 years. In the context of strengthening primary health care, our results show that equitable universal access to immunisation remains crucial to sustain health gains and continue to save future lives from preventable infectious mortality. WHO.

Cost-effectiveness and public health impact of typhoid conjugate vaccine introduction strategies in Bangladesh

PurposeTyphoid fever causes substantial morbidity and mortality in Bangladesh. The government of Bangladesh plans to introduce typhoid conjugate vaccines (TCV) in its expanded program on immunization (EPI) schedule. However, the optimal introduction strategy in addition to the costs and benefits of such a program are unclear. MethodsWe extended an existing mathematical model of typhoid transmission to integrate cost data, clinical incidence data, and recently conducted serosurveys in urban, semi-urban, and rural areas. In our primary analysis, we evaluated the status quo (i.e., no vaccination) and eight vaccine introduction strategies including routine and 1-time campaign strategies, which differed by age groups targeted and geographic focus. Model outcomes included clinical incidence, seroincidence, deaths, costs, disability-adjusted life years (DALYs), and incremental cost-effectiveness ratios (ICERs) for each strategy. We adopted a societal perspective, 10-year model time horizon, and 3 % annual discount rate. We performed probabilistic, one-way, and scenario sensitivity analyses including adopting a healthcare perspective and alternate model time horizons. ResultsWe projected that all TCV strategies would be cost saving compared to the status quo. The preferred strategy was a nationwide introduction of TCV at 9–12 months of age with a single catch-up campaign for children ages 1–15, which was cost saving compared to all other strategies and the status quo. In the 10 years following implementation, we projected this strategy would avert 3.77 million cases (95 % CrI: 2.60 – 5.18), 11.31 thousand deaths (95 % CrI: 3.77 – 23.60), and save $172.35 million (95 % CrI: −14.29 – 460.59) compared to the status quo. Our findings were broadly robust to changes in parameter values and willingness-to-pay thresholds. ConclusionsWe projected that nationwide TCV introduction with a catch-up campaign would substantially reduce typhoid incidence and very likely be cost saving in Bangladesh.

The Effectiveness of National Expanded Program on Immunization With Hepatitis A Vaccines in the Chinese Mainland: Interrupted Time-Series Analysis.

The high prevalence of hepatitis A delivered a blow to public health decades ago. The World Health Organization (WHO) set a goal to eliminate viral hepatitis including hepatitis A by 2030. In 2008, hepatitis A vaccines were integrated into the Expanded Program on Immunization (EPI) in China to alleviate the burden of hepatitis A, although the effectiveness of the EPI has not been well investigated. We aimed to evaluate the intervention effect at both provincial and national levels on the incidence of hepatitis A in the Chinese mainland from 2005 to 2019. Based on the monthly reported number of hepatitis A cases from 2005 to 2019 in each provincial-level administrative division, we adopted generalized additive models with an interrupted time-series design to estimate province-specific effects of the EPI on the incidence of hepatitis A among the target population (children aged 2-9 years) from 2005 to 2019. We then pooled province-specific effect estimates using random-effects meta-analyses. We also assessed the effect among the nontarget population and the whole population. A total of 98,275 hepatitis A cases among children aged 2-9 years were reported in the Chinese mainland from 2005 to 2019, with an average annual incidence of 5.33 cases per 100,000 persons. Nationally, the EPI decreased the hepatitis A incidence by 80.77% (excess risk [ER] -80.77%, 95% CI -85.86% to -72.92%) during the study period, guarding an annual average of 28.52 (95% empirical CI [eCI] 27.37-29.00) cases per 100,000 persons among the target children against hepatitis A. Western China saw a more significant effect of the EPI on the decrease in the incidence of hepatitis A among the target children. A greater number of target children were protected from onset in Northwest and Southwest China, with an excess incidence rate of -129.72 (95% eCI -135.67 to -117.86) and -66.61 (95% eCI -67.63 to -64.22) cases per 100,000 persons on average, respectively. Intervention effects among nontarget (ER -32.88%, 95% CI -39.76% to -25.21%) and whole populations (ER -31.97%, 95% CI -39.61% to -23.37%) were relatively small. The EPI has presented a lasting positive effect on the containment of hepatitis A in the target population in China. The EPI's effect on the target children also provided a degree of indirect protection for unvaccinated individuals. The continuous surveillance of hepatitis A and the maintenance of mass vaccination should shore up the accomplishment in the decline of hepatitis A incidence to ultimately achieve the goal set by the WHO.

Improved vaccination coverage after two rounds of multi-antigenic catch-up vaccination in Mauritania.

Although Mauritania carried out its Expanded Programme on Immunization (EPI), in 2015 the goal of vaccination coverage (VC) remained unmet in Bassikounou district and Mbera camp, contexts with large migrant populations. In response, during 2018, the national authorities, together with Médecins Sans Frontières organised two rounds of multi-antigenic mass vaccination campaigns (2RMASVC). The campaigns included oral polio (OPV), pneumococcal (PCV13), pentavalent and rotavirus vaccines for all eligible children six weeks to 59 months old. This study describes the results of the 2RMASVC. Cross-sectional household VC surveys (VCS1 and VCS2) were conducted before and after the 2RMASVC. Data were collected on vaccination status according to self-reporting and vaccination cards, and on reasons for non-vaccination (RNV). In total, 4,569 children received at least one dose of vaccine in the first round and 5,602 children in the second. Baseline VC, as fully vaccinated, according to VCS1, was 59.9% of children 12 to 59 months in Bassikounou district and 65.8% in Mbera camp. After the 2RMASVC, the coverages increased to 84.7% and 75.9% respectively. Absence from home, lack of motivation, late initiation of vaccinations and lack of awareness about vaccination were the main RNV during the 2RMASVC. Although the 2RMASVC did not reach its goal of 90%-95% VC, the strategy significantly increased VC in the two settings for children aged 12 to 59 months. Therefore, this catch-up approach could be considered to improve VC of children who miss out of the EPI strategy in resource-limited settings.

Assessment of Parents' Knowledge, Attitudes, and Satisfaction of Childhood Immunization: A Cross-Sectional Survey from a Rural District of Sindh, Pakistan

Background: Immunization is a cornerstone of public health, preventing millions of deaths annually, especially among children. Despite global efforts to increase vaccination coverage, significant gaps remain, influenced by parental knowledge, attitudes, and satisfaction with immunization services. These gaps are particularly pronounced in rural and socio-economically disadvantaged regions. Objective: This study aimed to assess parents' knowledge, attitudes, and satisfaction regarding childhood immunization and to identify barriers to vaccination in a rural district of Sindh, Pakistan. Methods: A cross-sectional survey was conducted in two cities, Mirpurkhas and Digri, within the Mirpur Khas district. Using the Raosoft® Sample Size Calculator, a sample size of 382 participants was determined with a 95% confidence level and a 5% margin of error. Participants were selected through convenience sampling. Data collection involved a semi-structured questionnaire developed from extensive literature review and validated through expert focus group discussions. The questionnaire covered demographics, perceptions of immunization, knowledge of the Expanded Programme on Immunization (EPI) schedule, and satisfaction with immunization services. Data analysis employed SPSS version 25, utilizing descriptive statistics and Mann-Whitney tests to analyze differences between variables. Results: Among 382 respondents, 55.76% were male, and 44.24% were female. A significant proportion (43.45%) were aged between 21–30 years. The majority acknowledged the importance of immunization (96.85% agreement), yet knowledge gaps were evident, with only 10.98% correctly identifying vaccines given at birth. Satisfaction with immunization services was high (73.56% satisfied with hospital services), despite 88.46% reporting incorrect knowledge about the vaccine given at birth. Barriers identified included affordability, vaccine unavailability, and long waiting times. Conclusion: While parental attitudes towards immunization were largely positive, significant knowledge gaps and barriers to immunization persist. Efforts to improve immunization coverage in rural Pakistan must address these knowledge deficits and structural barriers, emphasizing the development of targeted awareness campaigns and enhancing the accessibility and quality of immunization services.

Factors impacting sustained coverage inthe context ofdonor transitions: experience from Sri Lanka.

Although not reliant on donor funding for health, the external assistance that Sri Lanka receives contributes to the improvement of the health system and health outcomes. In this study, we evaluated transition experiences of the expanded programme on immunization (EPI) that received Gavi funding to expand the vaccine portfolio and the Anti-Malaria Campaign (AMC) that received funding from the Global Fund for AIDS, Tuberculosis and Malaria to scale-up interventions to target and achieve malaria elimination. We assessed if EPI and AMC programmes were able to sustain coverage of previously donor-funded interventions post-transition and explain the facilitators and barriers that contribute to this. We used a mixed methods approach using quantitative data to assess coverage indicators and the financing mix of the health programmes and qualitative analysis guided by a framework informed by the Walt and Gilson policy triangle that brought together document review and in-depth interviews to identify facilitators and barriers to transition success. The EPI programme showed sustained coverage of Gavi-funded vaccines post-transition and the funding gap was bridged by mobilizing domestic financing facilitated by the Gavi co-financing mechanism, full integration within existing service delivery structures, well-established and favourable pharmaceutical procurement processes for the public sector and stewardship and financial advocacy by technically competent managers. Although the absence of indigenous cases of malaria since 2012 suggests overall programme success, the AMC showed mixed transition success in relation to its different programme components. Donor-supported programme components requiring mobilization of operational expenses, facilitated by early financial planning, were successfully transitioned (e.g. entomological and parasitological surveillance) given COVID-19-related constraints. Other key programme components, such as research, training, education and awareness that are dependent on non-operational expenses are lagging behind. Additionally, concerns of AMC's future financial sustainability within the current structure remain in the context of low malaria burden.

Is It Not The Right Time To Consider Trivalent Mumps Vaccine (MMR) In The National Immunization Programme of Nepal? If Not Now, Then When?

Vaccination is the process of administration of a vaccine to help the immune system develop immunity from a disease resulting in reduction of child mortality, morbidity and disability in vaccine preventable diseases. Nepal started its pilot vaccination program in 1979 (2034 B.S) and after a decade (1989), the Expanded Program on Immunization (EPI) was followed to the whole country with the aim of universal vaccination in children. National immunization programme (NIP) provides vaccination services free of cost to the children living in marginalized  communities  and  geographical  regions difficult to reach through outreach sessions. Although many more vaccines have been added to the NIP of Nepal since then, vaccination against mumps is still missing.  Nepalese children are being vaccinated with MR vaccine (measles and rubella) at 9 completed months and a booster at 15 months in spite of MMR (measles, mumps and rubella) vaccine. The time to re-think and consider mumps vaccine (MMR) in the immunization schedule of Nepal by the government of Nepal has arrived now. Including MMR vaccine in the national immunization schedule would ultimately result in the reduction of the outbreaks and associated morbidity that occur annually along with the economic benefits.  

Factors associated with full vaccination and zero vaccine dose in children aged 12–59 months in 6 health districts of Cameroon

BackgroundRoutine immunisation coverage in Cameroon is still below the target of the national Expanded Programme on Immunisation (EPI), with only 42% of children fully immunised according to Demographic and Health Survey (DHS) report in 2018. The objective of this study was to evaluate factors associated with full immunisation and zero-dose in Cameroonian children.MethodsA two-stage cross-sectional cluster survey was conducted in Yaoundé in November 2021, targeting children aged 12–59 months. The clusters were chosen with probability proportionate to population size (PPS), and households selected by restricted sampling technique. Data were collected from the vaccination card of the child or from parents’ recall, if the card was not available, using electronic forms with tablets. Using R (version 4.1.0.), the proportion of fully immunised children was calculated. The household wealth index was described using principal component analysis, and factors associated with full immunisation assessed with multiple logistics regression. The threshold of statistical significance was set at 5%.FindingsA total, 273 children aged 12–59 months enrolled; 37% of participants were fully immunised, and 16% had never received any vaccine. Mother’s level of education: Primary (OR = 3.59, p = 0.0200), high school (OR = 3.68, p = 0.0400*), and higher education (OR = 8.25, p = 0.0018), and sharing household with biological father (OR = 2.11, p = 0.0305) were significantly associated with full vaccination. Living in a richer (3rd-5th wealth quintiles) household (OR = 0.25, p = 0.0053); mother’s education: Primary (OR = 0.07, p = 0.0271) and Higher education (OR = 0.10, p = 0.0419), living with the mother (OR = 0.05, p =  < 0.0001) and living with the father (OR = 0.22, p = 0.0253) had significant negative association with zero-dose in children.ConclusionThe proportion of fully vaccinated children in Yaounde is lower than the national average. Children from poor homes and those borne by uneducated mother have higher odds of not being vaccinated. Immunisation programmes in Yaounde need to be stepped up to improve coverage. Equally, there is a need to reconsider how the poor can the better reached with immunisation services.

Post-marketing safety surveillance of the rotavirus vaccine in India

BackgroundROTASIIL, an oral live attenuated bovine-human reassortant pentavalent rotavirus vaccine, was approved in 2017. This post-marketing surveillance (PMS) was conducted to collect real-world data on the safety of ROTASIIL in India. MethodsObservational, active PMS was conducted in approximately 10,000 infants aged ≥ 6 weeks. ROTASIIL was administered as a 3-dose regimen, at least 4 weeks apart, beginning at ≥ 6 weeks of age concomitantly with other Expanded Programme on Immunization (EPI) vaccines. Participants were followed for one month after the last dose. The adverse events (AEs) and serious adverse events (SAEs), including intussusception (IS) reported during the follow up period were collected. FindingsA total of 9940 infants were enrolled and were considered for safety analysis. Around 9913 (99.7 %) infants received 2 doses, while 9893 (99.5 %) infants completed all three doses. Total 3693 AEs were reported in 2516 (25.3 %) participants. Most of these AEs were pyrexia (78.01 % of events) and injection-site reactions (19.14 % of events). Nearly all AEs were causally unrelated to orally administered ROTASIIL and could be caused by the concomitant injectable vaccines. Only 4 AEs (2 events of vomiting and 1 event each of discomfort and pyrexia) in 4 (<0.1 %) participants could be related to ROTASIIL. AEs were of mild or moderate severity and all resolved without any sequelae. A total of 2 SAEs (acute otitis media and skull fracture) were reported in 2 (<0.1 %) participants and were not related to ROTASIIL and recovered without sequelae. No case of IS was reported. InterpretationROTASIIL was safe and well tolerated in this study. No safety concerns were reported. FundingThe study was funded by SIIPL which is the manufacturer of the study product.

Missed opportunity for routine vaccination and associated factors among children aged 0-23 months in public health facilities of Jimma Town.

The current recommendation obligates children to receive all vaccines within two years of birth. The Expanded Program on Immunization (EPI) was established in Ethiopia to increase the immunization rate by 10% annually and to reach 100% in 10 years but not been achieved in twenty years. Missed opportunity for vaccination (MOV) is one of the major factors in vaccination coverage. Hence, this study aimed to assess the prevalence of MOV and associated factors in Jimma Town public health facilities. A facility-based cross-sectional study design was employed with a quantitative data collection method. The sample size was calculated using a single population proportion formula. The data were collected through face-to-face interviews, and data extraction methods and analyzed using SPSS version 26. The statistical association was decided at p-value <0.05 with 95% CI, and AOR. A total of 422 children were involved in this study making a 100% response rate. The magnitude of MOV was 39.8% (95%CI: 35-45). Parents/caretakers have not attended formal education (AOR = 4.65, CI:1.64-13.24), residing in rural (AOR = 2.60, CI: 1.35-5.03), poor knowledge about immunization (AOR = 2.61, CI: 1.58-4.30), the child not assessed for vaccination status (AOR = 3.01, CI: 1.65-5.49), and parents/caretakers not seen/heard vaccination message in the last month (AOR = 2.42, CI: 1.40-4.18) were statistically positively associated with the MOV. In conclusion, this study indicated that MOV among the children was high in the study facilities. The researchers recommended stakeholders work on strengthening community awareness creation. Additionally, further study incorporating physician-related factors is also suggested.

Optimising DTwP-containing vaccine infant immunisation schedules (OptImms) — a protocol for two parallel, open-label, randomised controlled trials

BackgroundUniversal immunisation is the cornerstone of preventive medicine for children, The World Health Organisation (WHO) recommends diphtheria-tetanus-pertussis (DTP) vaccine administered at 6, 10 and 14 weeks of age as part of routine immunisation. However, globally, more than 17 unique DTP-containing vaccine schedules are in use. New vaccines for other diseases continue to be introduced into the infant immunisation schedule, resulting in an increasingly crowded schedule. The OptImms trial will assess whether antibody titres against pertussis and other antigens in childhood can be maintained whilst adjusting the current Expanded Programme on Immunisation (EPI) schedule to provide space for the introduction of new vaccines.MethodsThe OptImms studies are two randomised, five-arm, non-inferiority clinical trials in Nepal and Uganda. Infants aged 6 weeks will be randomised to one of five primary vaccination schedules based on age at first DTwP-vaccination (6 versus 8 weeks of age), number of doses in the DTwP priming series (two versus three), and spacing of priming series vaccinations (4 versus 8 weeks). Additionally, participants will be randomised to receive their DTwP booster at 9 or 12 months of age. A further sub-study will compare the co-administration of typhoid vaccine with other routine vaccines at one year of age. The primary outcome is anti-pertussis toxin IgG antibodies measured at the time of the booster dose. Secondary outcomes include antibodies against other vaccine antigens in the primary schedule and their safety.DiscussionThese data will provide key data to inform policy decisions on streamlining vaccination schedules in childhood.Trial registrationsISRCTN12240140 (Nepa1, 7th January 2021) and ISRCTN6036654 (Uganda, 17th February 2021).

Assessment of quality of routine immunization in rural areas of Doiwala Block, Dehradun

ABSTRACT Background: India initiated Expanded Programme on Immunization (EPI) in 1978 and was renamed to Universal Immunization Programme (UIP) in 1985 and subsequently integrated with National Rural Health Mission (NRHM) in 2005. Many studies have shown that health workers involved in immunization are more concerned towards coverage than the quality of immunization services provided. Aims and Objectives: This study aimed to assess the quality of routine immunization services in rural areas of Doiwala Block of Dehradun, Uttarakhand. Material and Methods: It was a cross-sectional study conducted for a duration of one year. Study participants included Auxillary Nurse Midwives (ANMs), Accredited Social Health Activists (ASHAs), Anganwadi Workers (AWWs) and parents/caregivers of children aged 12–23 months residing in that area who had received immunization services on the day of the survey. Institutional ethics committee clearance was obtained before the start of the study. A P value of &lt;0.05 was considered as statistically significant. Results: ASHAs at two centres in low-performing centres had never undergone any training for routine immunization but there was no statistically significant difference found between high and low-performing centres (P &gt; 0.05). The most common vaccine not available was the Bacillus Calmette–Guérin (BCG) vaccine. The majority of clients at both high (92%) and low-performing centres (96%) said that they never waited for at least 30 min post-vaccination at the vaccination site for observation. Conclusion: The study highlights that most of the ANMs at the immunization centre were having good knowledge and were adequately trained for maintaining cold chains at session sites.

[Increasing the efficiency of a mobile EPI strategy using injectable polio vaccine in Africa].

In 1980, partners initiated a mobile simplified EPI (Expanded programme on immunization) strategy for immunizing, with mobile teams, rural and urban populations in Western Africa. This strategy delivered EPI vaccines in two sessions: 1) 3-8 month-old children: BCG-Diphteria Tetanus Pertussis + reinforced killed Polio vaccine; 2) 9-15 month-old children: Diphteria Tetanus Pertussis + reinforced killed Polio vaccine, Measles-Yellow Fever. This strategy was compared to WHO-UNICEF extended EPI strategy, but results were never published in the context of a planned rapid polio eradication with oral polio vaccine. For comparison with standard WHO-UNICEF extended EPI strategy, using oral polio vaccine in four sessions, all the costs generated by these two strategies in 1988 have been collected in two adjacent zones in Burkina Faso, Western Africa: 203,642 inhabitants for WHO-UNICEF extended EPI strategy (Yako); 109,483 inhabitants for mobile simplified EPI strategy (Gourci). An EPI coverage survey at the end of this year has been done in these two adjacent zones with efficiency (costs per fully immunized child) computed. In Africa, the simplified mobile EPI strategy using reinforced killed polio vaccine was found two times more efficient (12.71 US$ per fully immunized child) than WHO-UNICEF extended EPI strategy using oral polio vaccine (29.67 US$ per fully immunized child), even if DTP-reinforced killed polio vaccine (0.52 US$ per dose) was more expensive than DTP and oral polio vaccine (0.14 US$ for the combined dose). The missed opportunities uncaught up would have doubled coverage in the WHO-UNICEF extended EPI strategy, versus only a 10% increase with the mobile simplified EPI strategy. The main reason for uncaught up missed opportunities in WHO extended EPI strategy was the absence of requested vaccine delivered by a health agent when attending population at meeting point, due to insufficient cold box volume carried on his moped for transport of vaccine. After 30 years, since 1990, of poliomyelitis eradication in Africa using oral polio vaccine and with non-added costs in this study of polio mass campaigns, these results should be published to review EPI strategy.

Timeliness and missed opportunities for vaccination among children aged 0 to 23 months in Dschang health district, West region, Cameroon: A cross-sectional survey.

Missed opportunities for vaccination (MOV) reflect quality of immunization service. The objective of this study was to assess vaccination timeliness, prevalence, and characteristics of MOVs among children aged 0-23 months, as well as knowledge, attitude and practice of health workers towards immunization. An exit interview method was used to select caregivers and health personnel. Selection took place in 26 health facilities within 14 health areas in the Dshcang Health district. Data were collected using two face-to-face questionnaires adapted from the World Health Organization (WHO) tools. We conducted an evaluation of all free vaccines in the Expanded Programme on Immunisation (EPI). We studied timeliness, assessed MOV, and knowledge, behaviour and attitude of health workers on immunization. Basic statistical tests were used to study the association between MOV and socio demographic characteristics. A total of 363 children aged 0 to 23 months were surveyed. A total of 88 (91.66%) of health personnel agreed to participate in our study. A total of 298 (82.1%) children had vaccination cards with dates, leading to 18% not completely vaccinated. Vaccination timeliness ranged from 20% to 77%. Overall MOV estimated was 23.83%, range from 0% to 16.4% among all vaccines. Among health workers, 70.45% (62/88) had insufficient knowledge on vaccination, 73.86% assessed the vaccination status of children during any routine visit and 74% ask parents to bring the child's vaccination record to any health facility visit. The study highlighted presence of MOV among children. Strategies for remedying this includes strengthening parents' knowledge, organizing refresher courses for health workers on vaccination, and systematically assessing children's vaccination status.

HTA70 Use of Economic Evaluation of Vaccines: The Experience in Colombia, 2000 to 2021

To describe the use of economic evaluation to update the antigens dispensed by the Colombian Expanded Program on Immunization (EPI) from 2000 and 2021.

Efficacy of Hepatitis B Vaccination Procedures in Infants and Children Born from HBsAg-positive Mothers in Iran: A Case Study of Khorasan Razavi Province, Iran

Background: Viral infections have been a major public health concern in recent years. Viral hepatitis B virus (HBV) is one of the serious healthcare system issues in Iran. Family transmission of HBV in pregnant women is a major cause of the high prevalence of HBV infection in neonates and related persons. The expanded program on immunization (EPI) was the main way to prevent this infection. Objectives: This study aimed to estimate the effectiveness of the hepatitis B vaccine in infants born to HBsAg-positive mothers in Khorasan Razavi province. Materials and Methods: This cross-sectional descriptive study was conducted on 53 HBsAg-positive women between March 2017 and April 2019 in Khorasan Razavi province, Iran. The enzyme-linked immunosorbent assay (ELISA) was employed to conduct screenings for HBsAg in children. Risk factors for HBV infection were investigated using medical records and structured questionnaires. Results: The prevalence of HBsAg positivity was 1.2% (1/83) among children aged 1-3 years old. All children received three doses of HBV vaccine according to the HBV immunization program. The positive hepatitis B surface antibody (HBsAb) test among children under study was 80.7% (n=67). Conclusion: The results indicated a low prevalence of hepatitis B infection among infants and children born to HBsAg-positive mothers (1.2); however, protective anti-HBs levels were reported in 80.7% (&lt;95%) of the children. It appears that the efficiency level of the hepatitis B vaccination procedure was not sufficient in this study. Overall, revaccination is recommended for children who are anti-HBs-negative or not protected.

Seroprevalence of hepatitis B virus infection in pre-mass vaccination era among children residing in a rural area of Bangladesh

Background and objectives: There are few details available regarding the prevalence of hepatitis B virus (HBV) infection in the general Bangladeshi population. There is a dearth of data on prevalence of HBV infection in children and adolescents who were born before the hepatitis B vaccine was introduced in the Expanded Program on Immunization (EPI). The objective of the current study was to use archived data to describe the seroepidemiology of HBV infection (HBsAg and anti-HBc Antibody) among school children in a particular rural area of Bangladesh. Also, the study correlated serum vitamin A level with the HBV infection status among a subset of children. Materials and method: The study analyzed the archived data of a study conducted in 2003 and 2004. The samples were collected from 1995 children, aged 5 to 15 years, from a purposively selected rural area located about 100 km north-east of capital Dhaka. HBsAg (HBV surface antigen) and anti-HBc antibody were determined by ELISA method. Vitamin A (retinol) in blood was assayed by HPLC technique. The prevalence rates of HBsAg and anti-HBc antibody was determined by simple percentages. All associations between different characteristics were tested by Chi square test. Results: Of the total 1995 children, 988 (49.5%) and 1007 (50.5%) were male and female respectively. Among them, 23 (1.2%) were HBsAg positive or HBV carriers and 79 (8.1%) were anti-HBc antibody positive. Neither HBsAg nor anti-HBc antibody positivity rate showed any difference in male and female children. There was also no significant difference of HBsAg positivity rate amongst children of different age groups; whereas, anti-HBc antibody positivity rate increased significantly (p &lt;0.005) with increase of age. Serum vitamin A was estimated in a subset of children. The mean serum vitamin A concentration was found significantly (p&lt;0.05) lower among HBsAg positive children compared to their age and sex matched healthy control group. Conclusion: This study has demonstrated that rural children are in risk of exposure to HBV infection. Increasing HBV seropositivity with age emphasizes the need for devising prevention strategies and to create awareness among the rural children. Further studies are necessary to find out the hitherto undetected sources namely occult hepatitis B cases and the ways of spread of HBV in the community. IMC J Med Sci. 2023; 17(2):007. DOI: https://doi.org/10.55010/imcjms.17.017 *Correspondence: M Abu Sayeed, Department of Community Medicine, Ibrahim Medical College, 1/A, Ibrahim Sarani, Segunbagicha, Dhaka 1000, Bangladesh; Email: sayeed1950@gmail.com; J. Ashraful Haq, Department of Microbiology, Ibrahim Medical College, Segunbagicha, Dhaka, Bangladesh; Email: jahaq54@yahoo.com

Immunogenicity of the pentavalent DTwP-HB-Hib vaccine (Shan-5) used in the Thai Expanded Program on Immunization compared to the hexavalent DTaP-HB-Hib-IPV and DTwP-HB-Hib (Quinvaxem) vaccines administered to infants at 2, 4, 6 months of age

BackgroundThe pentavalent DTwP-HB-Hib (Shan-5) vaccine was first introduced into the Thailand Expanded Program on Immunization (EPI) in 2019. The Shan-5 vaccine is administered to infants at 2, 4, and 6 months of age, after initial vaccination with monovalent hepatitis B (HepB) and Bacillus Calmette-Guérin (BCG) vaccines at birth. This study compared the immunogenicity of the HepB, diphtheria, tetanus, and Bordetella pertussis antigens incorporated in the EPI Shan-5 vaccine versus the optional pentavalent (DTwP-HB-Hib) Quinvaxem and hexavalent (DTaP-HB-Hib-IPV) Infanrix-hexa vaccine. MethodsThree-dose Shan-5-vaccinated children were prospectively enrolled at the Regional Health Promotion Centre 5, Ratchaburi province, Thailand, between May 2020 and May 2021. Blood sampling was performed at months 7 and 18. The levels of HepB surface antibody (anti-HBs), anti-diphtheria toxoid (DT) IgG, anti-tetanus toxoid (TT) IgG, and anti-pertussis toxin (PT) IgG were evaluated using commercially available enzyme-linked immunoassays. ResultsAnti-HBs levels of ≥10 mIU/mL were achieved in 100 %, 99.2 %, and 99.2 % of infants in the Shan-5 EPI group, hexavalent group and Quinvaxem group one month after four dose immunization (at 0, 2, 4, 6 months of age), respectively. The geometric mean concentrations of the EPI Shan-5 and hexavalent groups were comparable but were higher than those of the Quinvaxem group. At one month after primary vaccination (month 7), infants in the Shan-5 EPI group had significantly higher levels of anti-DT IgG, anti-TT IgG, and anti-PT IgG than infants in the hexavalent and Quinvaxem groups. ConclusionsThe immunogenicity of the HepB surface antigen in the EPI Shan-5 vaccine was similar to that achieved by the hexavalent vaccine, but was higher than that achieved by the Quinvaxem vaccine. The Shan-5 vaccine is highly immunogenic and generates robust antibody responses after primary immunization.

Childhood Bacterial Meningitis Surveillance in Southern Vietnam: Trends and Vaccination Implications From 2012 to 2021.

This retrospective hospital-based surveillance aimed to assess the epidemiology, causative pathogens trend, and serotypes distribution of pneumococcal meningitis among children aged under 5 years with bacterial meningitis in Southern Vietnam after the introduction of pentavalent vaccine in the Expanded Program on Immunization (EPI). From 2012 to 2021, cerebrospinal fluid samples were collected from children aged under 5 years with suspected bacterial meningitis at Children's Hospitals 1 and 2 in Ho Chi Minh City. Probable bacterial meningitis (PBM) cases were identified using biochemistry and cytology. Real-time polymerase chain reaction was used to confirm cases of confirmed bacterial meningitis (CBM) caused by Streptococcus pneumoniae, Haemophilus influenzae, or Neisseria meningitidis. Streptococcus pneumoniae serotyping was performed. Of the 2560 PBM cases, 158 (6.2%) were laboratory-confirmed. The CBM proportion decreased during the 10-year study and was associated with age, seasonality, and permanent residence. Streptococcus pneumoniae was the most common pathogen causing bacterial meningitis (86.1%), followed by H influenzae (7.6%) and N meningitidis (6.3%). The case-fatality rate was 8.2% (95% confidence interval, 4.2%-12.2%). Pneumococcal serotypes 6A/B, 19F, 14, and 23F were the most prevalent, and the proportion of pneumococcal meningitis cases caused by the 10-valent pneumococcal conjugate vaccine (PCV) serotypes decreased from 96.2% to 57.1% during the PCV eras. Streptococcus pneumoniae is the most frequent causative agent of bacterial meningitis in children aged under 5 years in Southern Vietnam over the last decade. Policymakers may need to consider introducing PCVs into the EPI to effectively prevent and control bacterial meningitis.

Infrastructure and Software Skills in the Expanded Program on Immunization at Commune Health Centers in Central Vietnam: A Cross-Sectional Mixed-Methods Study.

The application of the National Immunization Information System at primary health facilities is crucial in improving the quality of medical examinations as well as collecting and reporting immunization information. This study aimed to describe the infrastructure for the Expanded Program on Immunization's software at communes/wards/towns health centers (CHCs) of a province in central Vietnam and to evaluate the capacity of using immunization software of health officers. Another objective was to identify factors associated with skills in using the software of participants. A cross-sectional study combined with qualitative and quantitative methods was conducted, including 237 health officers from 50% (76/152) CHCs of Thua Thien Hue Province. Data were collected through face-to-face interviews using a developed questionnaire and observation via checklists. The results showed that most CHCs had sufficient infrastructure for the Expanded Program on Immunization (EPI). Health officers proficient in using the National Immunization Information System accounted for 74.7%. The CHCs should be equipped with more devices serving the immunization information management system and regularly maintain the equipment and the internet connection. Training health officers at CHCs in the data management of the vaccination system and record tracking ability using the National Immunization Information System is needed.