National Immunization Program Research Articles

The Frequency of Rotavirus Gastroenteritis in Children from West of Iran and Genotyping of Rotavirus Isolates: A Suggestion for Further Changes in Childhood Immunization Program.

Rotavirus is the most common cause of gastroenteritis among children. Currently, four oral live-attenuated vaccines are available to prevent rotavirus infection. The World Health Organization (WHO) has recommended including rotavirus vaccination in national immunization programs; however, it has not been introduced to the Iranian national immunization program. The study aimed to assess the frequency of rotavirus gastroenteritis in the west of Iran and investigate the necessity of rotavirus vaccination. Study Design: A case series study. In this case series study, 284 cases under six years of age who presented with acute gastroenteritis from March 2021 to 2022 to a referral hospital in the west of Iran were evaluated. Data on baseline characteristics, clinical manifestations, results of stool test, ELISA for rotavirus detection, and polymerase chain reaction (PCR) test for genotyping of rotavirus-positive samples were recorded. Results showed that the prevalence of rotavirus infection was 36.6%. The highest frequency was observed among children aged 6-12 months and during the autumn. According to the PCR results, G1P[8], G9P[8], G9P[4], and G1P [4] were the dominant genotypes, and 33.75% of samples were infected with multiple rotavirus genotypes. The study highlights the considerable prevalence of rotavirus infection among cases of acute gastroenteritis in children under six years of age who were referred to a referral hospital in the west of Iran and the high diversity of rotavirus genotypes in the targeted community. Consequently, physicians and health policymakers should prioritize strategies for the prevention and control of this infection, particularly by considering the rotavirus vaccine as a priority for the Iranian national immunization program.

Determinants of wealth-related inequalities in full vaccination coverage among children in Nepal: a decomposition analysis of nationally representative household survey data

BackgroundOver the past two decades, child health indicators in Nepal have improved significantly at the national level. Yet, this progress hasn’t been uniform across various population subsets. This study identified the determinants associated with childhood full vaccination, assessed wealth-related inequalities, and delved into the key factors driving this inequality.MethodsData for this study were taken from the most recent nationally representative Nepal Demographic and Health Survey 2022. A total of 959 children aged 12–23 months who had received routine childhood basic antigens as per the national immunisation program were considered for analysis. Binary logistic regression models were conducted to identify the associated factors with outcome variable (uptake of full vaccination). The concentration curve and Erreygers normalized concentration index were used to assess inequality in full vaccination. Household wealth quintile index scores were used to measure wealth-related inequality and decomposition analysis was conducted to identify determinants explaining wealth-related inequality in the uptake of childhood vaccination.ResultsThe coverage of full vaccination among children was 79.8% at national level. Several factors, including maternal health service utilisation variables (e.g., antenatal care, institutional delivery), financial challenges related to visiting health facilities, and mothers’ awareness of health mother group meetings within their ward, were associated with the uptake of full vaccination coverage among children. The concentration curve was below the line of equality, and the relative Erreygers normalized concentration index was 0.090, indicating that full vaccination was disproportionately higher among children from wealthy groups. The decomposition analysis identified institutional delivery (20.21%), the money needed to visit health facilities (14.25%), maternal education (16.79%), maternal age (8.53%), and caste (3.03%) were important contributors to wealth related inequalities in childhood full vaccination uptake.ConclusionsThere was notable wealth-related inequality in full vaccine uptake among children in Nepal. Multisectoral actions involving responsible stakeholders are pivotal in reducing the inequalities, including promoting access to maternal health services and improving educational attainment among mothers from socioeconomically disadvantaged communities.

ATAGI targeted review 2023: Vaccination for preventing influenza in Australia.

Annual seasonal influenza epidemics cause substantial disease and economic burden worldwide. During the coronavirus disease 2019 (COVID-19) pandemic in 2020 and 2021, influenza activity significantly declined. However, influenza resurged in Australia following the relaxation of non-pharmaceutical interventions, with increased influenza virus circulation in early 2022 coinciding with the SARS-CoV-2 Omicron BA.2 variant wave. Together with other respiratory virus diseases, these disease impacts on the Australian population and healthcare system have re-emphasised the importance of influenza vaccination and control. We aim to provide an overview of the current seasonal influenza vaccination program in Australia and summarise evidence and considerations underpinning potential future immunisation strategies. Influenza causes disproportionately higher morbidity and mortality in young children and older adults. Other populations at elevated risk from influenza include Aboriginal and Torres Strait Islander peoples, pregnant women, and people with certain underlying medical conditions. All Australians aged ≥ 6 months are recommended to receive influenza vaccine every year. The National Immunisation Program (NIP) provides free vaccine for eligible at-risk populations. While approximately 70% of older adults had received influenza vaccine in 2022, coverage in other age groups remains suboptimal. There are several key unmet needs and challenges, but also potential strategies for enhancing the influenza vaccination program in Australia. Improved monitoring and evaluation, including the use of relevant linked datasets for such purposes, is imperative to better understand variations in coverage and vaccination impact in specific populations. Adoption of evidence-based strategies, such as culturally appropriate resources that consider the characteristics of diverse Australian populations, may also help to achieve higher vaccine coverage rates. Additionally, greater vaccine uptake across the population could be facilitated by expanding the NIP-eligible population where cost-effective, and adopting the use of more effective and different types of vaccines when available.

Cross-sectional study of pharmacists’ knowledge and beliefs about human papillomavirus, its vaccines, and barriers related to vaccine administration

Abstract Background The human papillomavirus (HPV) vaccine is not currently included in the national immunization program in Jordan. The rising prevalence of cervical cancer in Jordan highlights the necessity for a novel approach to boost HPV vaccination rates. Thus, the main objective of this study was to assess the knowledge, beliefs, and potential barriers concerning HPV and HPV vaccine administration in community pharmacies. Methods This cross-sectional study, conducted in Jordan between July and September 2023, involved community pharmacists. Using a convenience sampling approach, one author visited various community pharmacies to distribute and collect questionnaires. A total knowledge score, out of a possible 10 points, and a belief score out of 40 were calculated for each pharmacists. Additionally, the study examined factors that may influence participants’ knowledge and belief levels. Results A total of 302 community pharmacists took part in the survey, with approximately two-thirds of the participants being female (n = 230, 76.2%). The average knowledge score about HPV was 2.7 out of 10 (standard deviation [SD] = 1.8), and linear regression analysis indicated no significant relationship between pharmacists’ knowledge about HPV and the factors studied, such as age, gender, area of pharmacy, and the acquired degree. In terms of beliefs, findings revealed that 63.2% supported an expanded role for community pharmacists in HPV vaccination. Three main barriers were identified: lack of parental knowledge (n = 218, 72.2%), insufficient educational materials for parents (n = 206, 68.2%), and inadequate provider knowledge (n = 201, 66.6%). Conclusions In summary, this study provides valuable insights into the knowledge, beliefs, and challenges surrounding HPV and HPV vaccination among community pharmacists in Jordan. To enhance the involvement of community pharmacists in promoting HPV vaccination and aiding in the prevention of HPV-related illnesses, it is crucial to address the identified knowledge gaps and obstacles.

Whole-Genome Characterization of Rotavirus G9P[6] and G9P[4] Strains That Emerged after Rotavirus Vaccine Introduction in Mozambique.

Mozambique introduced the Rotarix® vaccine into the National Immunization Program in September 2015. Following vaccine introduction, rotavirus A (RVA) genotypes, G9P[4] and G9P[6], were detected for the first time since rotavirus surveillance programs were implemented in the country. To understand the emergence of these strains, the whole genomes of 47 ELISA RVA positive strains detected between 2015 and 2018 were characterized using an Illumina MiSeq-based sequencing pipeline. Of the 29 G9 strains characterized, 14 exhibited a typical Wa-like genome constellation and 15 a DS-1-like genome constellation. Mostly, the G9P[4] and G9P[6] strains clustered consistently for most of the genome segments, except the G- and P-genotypes. For the G9 genotype, the strains formed three different conserved clades, separated by the P type (P[4], P[6] and P[8]), suggesting different origins for this genotype. Analysis of the VP6-encoding gene revealed that seven G9P[6] strains clustered close to antelope and bovine strains. A rare E6 NSP4 genotype was detected for strain RVA/Human-wt/MOZ/HCN1595/2017/G9P[4] and a genetically distinct lineage IV or OP354-like P[8] was identified for RVA/Human-wt/MOZ/HGJM0644/2015/G9P[8] strain. These results highlight the need for genomic surveillance of RVA strains detected in Mozambique and the importance of following a One Health approach to identify and characterize potential zoonotic strains causing acute gastroenteritis in Mozambican children.

Chimeric Viruses Enable Study of Antibody Responses to Human Rotaviruses in Mice.

The leading cause of gastroenteritis in children under the age of five is rotavirus infection, accounting for 37% of diarrhoeal deaths in infants and young children globally. Oral rotavirus vaccines have been widely incorporated into national immunisation programs, but whilst these vaccines have excellent efficacy in high-income countries, they protect less than 50% of vaccinated individuals in low- and middle-income countries. In order to facilitate the development of improved vaccine strategies, a greater understanding of the immune response to existing vaccines is urgently needed. However, the use of mouse models to study immune responses to human rotavirus strains is currently limited as rotaviruses are highly species-specific and replication of human rotaviruses is minimal in mice. To enable characterisation of immune responses to human rotavirus in mice, we have generated chimeric viruses that combat the issue of rotavirus host range restriction. Using reverse genetics, the rotavirus outer capsid proteins (VP4 and VP7) from either human or murine rotavirus strains were encoded in a murine rotavirus backbone. Neonatal mice were infected with chimeric viruses and monitored daily for development of diarrhoea. Stool samples were collected to quantify viral shedding, and antibody responses were comprehensively evaluated. We demonstrated that chimeric rotaviruses were able to efficiently replicate in mice. Moreover, the chimeric rotavirus containing human rotavirus outer capsid proteins elicited a robust antibody response to human rotavirus antigens, whilst the control chimeric murine rotavirus did not. This chimeric human rotavirus therefore provides a new strategy for studying human-rotavirus-specific immunity to the outer capsid, and could be used to investigate factors causing variability in rotavirus vaccine efficacy. This small animal platform therefore has the potential to test the efficacy of new vaccines and antibody-based therapeutics.

Mapping Adult Vaccine Confidence in Future Health Professionals: A Pilot Study among Undergraduate Students at Two Universities in Greece.

Health professionals' recommendations increase vaccine uptake. We aimed to document stances, practices regarding adult vaccination, and their predictors among undergraduate medical and biomedical science students, as well as their perspectives on increasing vaccine confidence. Among the 430 participants, third-year students from two universities in Greece, only 25.4% were in favor of all vaccines, while no refuters were detected. Predictors of recommending vaccination were the Attitudes Towards Adult Vaccination (ATAVAC) Value (OR 3.26, p < 0.001) and ATAVAC Safety subscales scores (OR 1.36, p < 0.05), being a medical student (OR 2.45, p < 0.05), and having better self-rated health status (OR 2.27, p < 0.05). The importance of getting vaccinated as health professionals was recognized by participants with a higher ATAVAC value (OR 5.39, p < 0.001), ATAVAC Safety scores (OR 1.46, p < 0.05), and increased knowledge regarding the National Immunization Program (OR 1.31, p < 0.05). The God Locus of Health Control (GLHC) was a predictor only in vaccination against COVID-19 (OR 0.91, p < 0.05). Improving community health literacy and health providers' education, boosting trust in authorities, and adopting a person-centered approach emerged as the main themes regarding how to increase vaccine confidence. Mapping health professionals' confidence in vaccines and providing lifelong training support is pivotal in supporting positive attitudes, enhancing their competence, and promoting vaccination in the post-COVID-19 era.

Child COVID-19 vaccine uptake among participants of the 2015 Pelotas (Brazil) Birth Cohort Study

ObjectiveTo analyze COVID-19 vaccine uptake in children and to investigate factors associated with two outcomes variables: (a) not even beginning; (b) not completing the COVID-19 vaccine series. MethodsWe used data of children aged 6–7 years from the 2015 Pelotas c Birth Cohort Study. COVID-19 vaccination status was collected from immunization cards and National Immunization Program Information System. Adjusted analyses were performed using a hierarchical model to identify factors associated with the two study outcomes. ResultsAmong 3867 children, 20.7 % (95 % CI, 19.5 %–22.0 %) did not even begin the 2-dose primary COVID-19 vaccine series, and 28.2 % (95 % CI, 26.6 %–29.8 %) did not complete the series with the second dose. Children not even beginning the COVID-19 vaccine series were more likely to have a White mother, not to have obesity, to have a history of COVID-19 infection, to have received non-recommended drugs for COVID-19, to be afraid of needles, and to have an incomplete diphtheria-tetanus-pertussis (DTP) and poliovirus immunization schedule. Not completing the 2-dose series was associated with lower maternal age and education, mother’s self-identification as White or Brown, lower household income, lack of access to health services, not having completed the DTP and poliovirus immunization schedule and living with a person with a history of infection with COVID-19. ConclusionThe results highlight a vaccine-hesitant parents’ group who chose not beginning the COVID-19 vaccine series of their children and, another group of parents who failure to complete the child’s series due to difficulty accessing health services.

Human papillomavirus (HPV) vaccination in Japan.

To review the status of human papillomavirus (HPV) vaccination in Japan from inception to the present, focusing on past and current challenges. Published articles and website content related to HPV vaccination were reviewed. The Ministry of Health, Labor and Welfare suspended proactive recommendations for HPV vaccination in June 2013 following repeated media reports of girls experiencing adverse events, including chronic pain and walking disturbances, after receiving the HPV vaccine. Despite later recognition of these symptoms as a functional somatic syndrome, HPV vaccine coverage of target girls aged 12 to 16 years in the National Immunization Program (NIP) rapidly decreased to near zero. This suspension of the proactive HPV vaccination recommendation ceased in fiscal year (f-year) 2022, initiating a 3-year catch-up free HPV vaccination period from April 2022 to March 2025 for women born from f-years 1997 to 2005. These drastic changes were driven by established evidence of the effectiveness and safety of HPV vaccines reported from both Japan and other countries, and a nine-valent HPV vaccine has been included in the NIP since f-year 2023. However, the estimated HPV vaccination rate in the NIP remains low at ≤30%. To regain high coverage of HPV vaccination in Japan, it is essential that government, industry, and academic society work together to raise awareness and educate Japanese people about cervical cancer prevention and HPV-related diseases.

Health Workers Perceived Hindrances to Implementation of National Programme on Immunization among People in Kwara State, Nigeria

Abstract Background: Childhood preventable illnesses that cause high rates of morbidity and mortality in Nigeria include poliomyelitis, tuberculosis, diphtheria, tetanus, measles, and hepatitis. Some factors prevent the effective implementation of the national immunization program among Kwara State residents, despite numerous interventions aimed at preventing them through routine immunization. This study investigated inadequate funding, lack of community involvement, and low public awareness as factors that prevented the implementation of the Kwara State’s national immunization program. Methods: A descriptive survey research design with 460 respondents was used in this study. Results: The results showed inadequate funding, low community involvement, and low public awareness impede the successful execution of the national immunization program in Kwara State, Nigeria. Conclusion: In Kwara State, Nigeria, inadequate funding, lack of community involvement, and lack of public awareness impede successful execution of the national immunization program.

Serotype distribution, antibiotic resistance, multilocus sequence typing, and virulence factors of invasive and non-invasive Streptococcus pneumoniae in Northeast China from 2000 to 2021.

Streptococcus pneumoniae infection is a major public health concern with high morbidity and mortality rates. This study aimed to evaluate the serotype distribution, antimicrobial resistance changes, clonal composition, and virulence factors of S. pneumoniae isolates causing pneumococcal disease in northeast China from 2000 to 2021. A total of 1,454 S. pneumoniae isolates were included, with 568 invasive strains and 886 non-invasive strains. The patients from whom the S. pneumoniae were isolated ranged in age from 26 days to 95 years, with those ≤ 5 years old comprising the largest group (67.19%). 19F, 19A, 23F, 14, and 6B were the most common serotypes, of which 19A and 19F were the main serotypes of invasive and non-invasive S. pneumoniae, respectively. CC271 was the most common multilocus sequence type. Serotype 14 had the lowest expression of cbpA, rrgA, and psrP genes, but expression levels of 19A and 19F genes were similar. All isolates were sensitive to ertapenem, moxifloxacin, linezolid, and vancomycin but highly resistant to macrolides, tetracyclines, and cotrimoxazole. Simultaneous resistance to erythromycin, clindamycin, tetracyclines, and trimethoprim/sulfamethoxazole was common pattern among multidrug-resistant isolates. Non-invasive S. pneumoniae had higher resistance to β-lactam antibiotics than invasive strains. 19A and 19F were the main strains of penicillin-resistant S. pneumoniae. The resistance rate of β-lactam antibiotics decreased from 2017 to 2021 compared to previous periods. Including PCV13 in the national immunization program can reduce the morbidity and mortality rates of pneumococcal disease effectively.

Clinical Profile of Hospitalized Varicella Cases From Pediatric Emergency Consultations: A Retrospective Cohort Study.

Varicella is a very common childhood infectious disease. It is generally benign, but it can lead to fatal complications. Our study aimed to describe theclinical and therapeutic profile of varicella based on consultations in the pediatric emergency department, to determine the incidence of hospitalized varicellacasesin the pediatric department for complementary management,and to specify the incidence of varicella complications in hospitalized patients. We conducted a retrospective descriptive cohort study over 12 months. It took place in the pediatrics and pediatric emergency departments of the Mother-Child Hospital of the Mohammed VI University Hospital, Mohammed I University, in Oujda, Morocco. We collected 120 cases of varicella. The mean age of patients was 4.5 years. The most common age range was 4-6 years (69%). Males predominated. The reason for consulting the pediatric emergency department wasa febrile rash in 65% of cases. Treatment in pediatric emergencies was mostly symptomatic. Antibiotic treatment for superinfection of lesions was used in 11% of cases. The number of hospitalizations due to complicated and/or severe varicella was 17 cases. The median age was 6.3 years. Most of the children (82%) were immunodeficient and 18% were immunocompetent.Sixteen patients had underlying risk factors. Infectious skin and soft tissue complications were noted in most hospitalized patients (47%). They were mainly presented by cutaneous reinfections with alteration of general health (41%). Neurological complications ranked second (23%). The majority were febrile convulsions (17%). One case of bronchopulmonary complication was noted. No hematological, digestive, renal, or cardiac complications were noted. Intravenous antiviral treatment was used in 88% of hospitalized cases. The drug of choice was acyclovir. Antibiotic therapy was used in 53% of cases. No patient received corticosteroid therapy.The median length of hospitalization for our patients was 14 days. The evolution was favorable in 100% of cases. Varicella remains a benign disease in children, rarely leading to hospitalization. However, complications may develop in cases of comorbidity or children with risk factors. The introduction of the varicella vaccine into the national immunization program could considerably reduce the number of children hospitalized in the near future.

Impact of the emergence of severe acute respiratory syndrome coronavirus 2 omicron variants on routine childhood immunization in Japan

BackgroundThe coronavirus disease 2019 (COVID-19) pandemic disrupted routine childhood vaccination worldwide, especially at the beginning of the pandemic. After the emergence of variants of concern, particularly the Omicron variants, the number of COVID-19 cases significantly increased, especially in children. However, the impact of the Omicron variants on routine childhood vaccination is unknown. MethodsThis retrospective observational study collected data on vaccines included in the Japanese national immunization program (NIP) of children 15 years or younger between 2016 and 2022 in Niigata, Japan. During the study period, hepatitis B virus vaccine and rotavirus vaccines were introduced to the NIP in October 2016 and October 2020, respectively. The monthly number of vaccine doses per eligible child population between 2020 and 2022 (pandemic period) was compared to the average number of vaccine doses in the corresponding month between 2016 and 2019 (pre-pandemic period). The effect of 8 surges of COVID-19 patients on trends in routine childhood vaccination was also analyzed. ResultsThe numbers of doses during the pre-Omicron pandemic period were comparable to the values administered before the pandemic. However, after the emergence of the Omicron variants, and especially after the surge of Omicron variant BA.5 in 2022, the number of vaccine doses declined. The decline was notable in second doses of MR vaccine at age 5–6 years by − 9.6 % and diphtheria-tetanus vaccine at ages 11–12 years by − 14.1 %. ConclusionsRoutine childhood immunization was significantly affected by the emergence of the Omicron variants most likely due to the facts that more candidates and their guardians contracted COVID-19, or were required isolation for close contacts. The findings highlight the importance of continued monitoring to maintain high coverage of routine childhood immunizations for controlling vaccine preventable diseases. A follow-up study should investigate changes in the number of declined vaccine doses during Omicron variant predominance.

The public health impact of recombinant herpes zoster vaccination in adults over 50 years in Spain

ABSTRACT The recombinant zoster vaccine (RZV) is included in the Spanish National Immunisation Programme for adults 65 years of age (years), with a potential progressive catch-up program for adults 66–80 years, starting with 80 years. However, the risk of herpes zoster (HZ) increases significantly from 50 years. We estimated the public health impact (PHI) of vaccinating adults ≥50 years in Spain versus no vaccination, using a Markov model adapted to the Spanish setting. The model simulated a hypothetical ≥50 years cohort over a lifetime, with inputs from Spanish publications, databases, or publications from other countries where Spanish data were unavailable. Base case inputs included 67.7% RZV coverage and 61.1% second dose compliance. Outputs included clinical outcomes avoided, healthcare resource use avoided, and number-needed-to-vaccinate (NNV) to prevent one HZ case. Deterministic (DSA) and probabilistic sensitivity analyses (PSA) were also conducted. The model estimated that, compared with no vaccination, vaccinating adults ≥50 years in Spain (N = 19,850,213) with RZV could prevent 1,533,353 HZ cases, 261,610 postherpetic neuralgia episodes, 274,159 other complications, and 138 deaths through the cohorts’ remaining lifetime, mostly in the 50–59 years cohort. Furthermore, 3,500,492 primary care visits and 71,156 hospitalizations could be avoided, with NNV = 9 to prevent one HZ case. DSA predicted NNV = 7 to prevent one HZ case when second dose compliance was increased to 100%. PSA demonstrated ≥200,000 and ≥1,400,000 cases could be prevented in 86.9% and 18.4% of simulations, respectively. Starting RZV from 50 years could therefore prevent a substantial number of HZ cases and complications. Increasing RZV coverage and second dose compliance could further alleviate PHI of HZ.

Australian vaccine preventable disease epidemiological review series: Hepatitis B, 2000-2019.

Hepatitis B vaccination was nationally funded for adolescents in 1996, with inclusion of universal infant immunisation under the National Immunisation Program (NIP) in May 2000. This study describes hepatitis B epidemiology in Australia in the two decades since 2000. This article analyses newly-acquired (within the prior 24 months) and unspecified (all other) hepatitis B notifications (2000-2019) from the National Notifiable Diseases Surveillance System; acute hepatitis B hospitalisations (2001-2019) from the National Hospital Morbidity Database; and acute (2000-2019) and chronic (2006-2019) hepatitis B deaths from the Australian Bureau of Statistics and Australian Coordinating Registry. Rates over the reporting period were described overall, and by age group, sex, and Aboriginal and Torres Strait Islander status (Aboriginal and/or Torres Strait Islander versus other [neither Aboriginal nor Torres Strait Islander, unknown or not stated]). Trend analyses were performed using Poisson or negative binomial regression. Additional analyses were performed for the cohort born after May 2000. The annual all-age notification rate per 100,000 per year declined (p < 0.001) from 2.13 in 2000 to 0.65 in 2019 for newly-acquired hepatitis B and from 38.3 to 22.3 for unspecified hepatitis B (likely to predominantly represent chronic hepatitis B). Newly-acquired and unspecified hepatitis B notification rates were lowest among children aged < 15 years. The most substantial reductions in notification rates of newly-acquired hepatitis B were among adolescents aged 15-19 years and young adults aged 20-24 and 25-29 years (respectively 17-, 11-, and 7-fold); these age groups also recorded the most substantial reductions in unspecified hepatitis B notifications (respectively 5-, 3.5-, and 2-fold). Newly-acquired hepatitis B notification and acute hepatitis B mortality rates were two- to threefold higher in males than females. The all-age newly-acquired hepatitis B notification rate in Aboriginal and Torres Strait Islander people decreased twofold between 2000 and 2019, but remained threefold higher than in other people. Acute hepatitis B hospitalisations also declined over the study period (p < 0.001) and followed similar patterns. There were no acute or chronic hepatitis B deaths among people born after May 2000; this cohort featured 52 newly-acquired and 887 unspecified hepatitis B notifications. Due to lack of data on country of birth (and hence eligibility for infant vaccination under the NIP or overseas programs), vaccination status and likely transmission routes, we were unable to assess factors contributing to these potentially preventable infections. Adolescent and infant immunisation under the NIP has led to significant reductions in notification rates of newly-acquired hepatitis B, and in acute hepatitis B hospitalisation rates, both overall and in Aboriginal and Torres Strait Islander people. Unspecified hepatitis B notification rates have also greatly decreased in children and young adults, likely largely due to the impact of overseas infant immunisation programs on prevalence in child and adolescent migrants. Work to improve completeness of variables within national datasets is crucial, along with enhanced surveillance of both newly-acquired and unspecified hepatitis B cases to investigate transmission routes, vaccination status and factors contributing to acquisition of hepatitis B, in order to optimise the impact of immunisation programs and ensure linkage with care.

Cost-effectiveness analysis of the pediatric 20-valent pneumococcal conjugate vaccine compared with lower-valent alternatives in Argentina

ObjectivesThe 13-valent pneumococcal conjugate vaccine (PCV13) has been recommended for infants in Argentina’s national immunization program (NIP) in a 2 + 1 schedule since 2012. Licensure of the 15-valent vaccine (PCV15) is anticipated soon, and the 20-valent vaccine (PCV20) recently received regulatory approval. This cost-effectiveness analysis examined the public health and economic implications of transitioning from PCV13 to either PCV15 or PCV20 in Argentina’s pediatric NIP. MethodsA decision-analytic Markov model was used with a 10-year time horizon and a 3.0% annual discount rate for costs and benefits. Vaccine effectiveness estimates were derived from Argentinian surveillance data, PCV13 clinical effectiveness and impact studies, and PCV7 efficacy studies. Population, epidemiologic, and economic inputs were obtained from literature and Argentinian-specific data. The study adopted a healthcare system perspective; sensitivity and scenario analyses were conducted to assess input parameters and structural uncertainty. ResultsCompared with PCV13, PCV20 was estimated to avert an additional 7,378, 42,884, and 172,389 cases of invasive pneumococcal disease (IPD), all-cause pneumonia, and all-cause otitis media (OM), respectively, as well as 3,308 deaths, resulting in savings of United States Dollars (USD) 50,973,962 in direct medical costs. Compared with PCV15, PCV20 was also estimated to have greater benefit, averting an additional 6,140, 35,258, and 142,366 cases of IPD, pneumonia, and OM, respectively, as well as 2,624 deaths, resulting in savings of USD 37,697,868 in direct medical costs. PCV20 was associated with a higher quality-adjusted life year gain and a lower cost (i.e., dominance) versus both PCV13 and PCV15. Results remained robust in sensitivity analyses and scenario assessments. ConclusionOver a 10-year horizon, vaccination with PCV20 was expected to be the dominant, cost-saving strategy versus PCV13 and PCV15 in children in Argentina. Policymakers should consider the PCV20 vaccination strategy to achieve the greatest clinical and economic benefit compared with lower-valent options.

Retrospective Cross-Sectional Epidemiological Study of Human Papillomavirus-Associated Precancers and Anogenital Warts in Patients Attending Specialized Clinics in Russian Federation

Background. In Russia, there are no country level registries on HPV-associated pre-cancers (cervical intraepithelial neoplasia, CIN; vulvar intraepithelial neoplasia, VIN; vaginal intraepithelial neoplasia, VaIN; anal intraepithelial neoplasia, AIN; penile intraepithelial neoplasia PIN) and anogenital warts (AWs) and no national-level cervical cancer screening program. Aims — the aim of this study was to assess the proportion of patients with CIN, VIN, VaIN, AIN, PIN and AWs diagnosis in the clinical settings in Russia. Methods. This study was a non-interventional retrospective multi-center chart-review study in 28 investigational sites representing 21 Federal subjects of 6 Federal Districts of Russia. Medical charts of adult men and women visited gynecology, sexual health, dermatovenerology or urology services between 1 Jan 2000 — 31 Dec 2019 were reviewed. Data were abstracted, using a standardized approach, on patient demographic characteristics, presence or absence of pre-cancers and AWs diagnoses, method of diagnosing pre-cancer and HPV infection, and grade of neoplasia. Results. A total of 11 520 patients (1732 male and 9788 female) were included in the analysis. The overall proportion of patients with HPV-associated precancers and AWs was 10.8%. By service type, cases of HPV-associated conditions were revealed most often in dermatological departments (14.5%) and gynecological hospitals (13.8%). CIN detection rate in Russian clinical settings increased over the 20-years from 3.2 to 11.1% and was higher in gynecological in-patient departments compared to out-patient departments (12.5 and 5.2% respectively). The number of non-cervical precancers (VIN, VaIN, AIN, PIN) cases were very low (the detection rate was less than 1%). The frequency of HPV type 16 and 18 detection increased from 0.6 to 4.8%, and from 0.2 to 1.9%, respectively, for the 20-years period. Conclusions. Our study suggested high level of HPV-related pre-cancer and AW disease burden as well as presence of high-risk HPV types. Preventive strategy through effective national HPV immunization program would be beneficial to reduce HPV-related disease burden in Russia.

Effectiveness of two-dose vs. one-dose varicella vaccine in children in Shanghai, China: a prospective cohort study.

Varicella, a highly contagious viral disease caused by the varicella-zoster virus (VZV), affects millions globally, with a higher prevalence among children. After the initial infection, VZV lies dormant in sensory ganglia and has the potential to reactivate much later, causing herpes zoster (HZ). Vaccination is one of the most effective methods to prevent varicella, and the two-dose varicella vaccine (VarV) regimen is widely used around the world. In China, the VarV has been included in the national immunization programme with a recommended single-dose regimen. This study aimed to compare the effectiveness of the two-dose vs. one-dose VarV regimen in children in Shanghai, China. A prospective cohort study was conducted in Shanghai, China, from September 2018 to December 2022. The study enrolled children aged 3-18 years who had received either the one-dose, two-dose, or 0-dose VarV regimen. Vaccination history, varicella infection status, and relevant variables, including demographic information (name, date of birth and sex) and medical history (clinical features of varicella and illness duration) were collected through medical record review and parental interviews. A total of 3,838 children were included in the study, with 407 in the 0-dose regimen group, 2,107 in the one-dose regimen group and 1,324 in the two-dose regimen group. The corresponding incidence density in these groups was 0.13, 0.05 and 0.03 cases per 1,000 person-days, respectively. The adjusted vaccine effectiveness (VE) was 81.7% (95%CI: 59.3-91.8%) for the two-dose regimen and 60.3% (95%CI: 29.3-77.7%) for the one-dose regimen, compared to the 0-dose regimen. The two-dose VarV regimen showed a protective effectiveness of 47.6% (95%CI: 2.5-71.9%) compared to the one-dose VarV regimen. This study provides evidence supporting the greater effectiveness of the two-dose VarV regimen in preventing varicella infection compared to the one-dose regimen.

EPH28 Public Health Impact of Switching From a 13-Valent to a 15-Valent Pneumococcal Conjugate Vaccine in the Chilean National Immunization Program

EPH28 Public Health Impact of Switching From a 13-Valent to a 15-Valent Pneumococcal Conjugate Vaccine in the Chilean National Immunization Program

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

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. 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. 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%). 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.