Universal Vaccination Program Research Articles

Survey of hepatitis B virus infection status after 35 years of universal vaccination implementation in Taiwan.

Hepatitis B virus (HBV) vaccination programs in Taiwan are one of the earliest programs in the world and have largely reduced the prevalence of HBV infection. We aimed to demonstrate the vaccination efficacy after 35 years and identify gaps toward HBV elimination. A total of 4717 individuals aged 1-60 years were recruited from four administrative regions based on the proportion of population distribution. Serum levels of hepatitis B surface antigen (HBsAg), hepatitis B surface antibody (anti-HBs), and hepatitis B core antibody (anti-HBc) levels were assessed. HBV viral load, genotypes and HBsAg 'ɑ' determinant variants were evaluated if indicated. After 35 years of vaccination, the overall seropositivity rates for HBsAg and anti-HBc in Taiwan were 4.05% and 21.3%, respectively. The vaccinated birth cohorts exhibited significantly lower seropositivity rates for both markers compared to the unvaccinated birth cohorts (HBsAg: 0.64% vs. 9.78%; anti-HBc: 2.1% vs. 53.55%, respectively; p < 0.0001). Maternal transmission was identified as the main route of HBV infection in breakthrough cases. Additionally, increased prevalences of genotype C and HBsAg escape mutants were observed. The 35-year universal HBV vaccination program effectively reduced the burden of HBV infection, but complete eradication of HBV infection has not yet been achieved. In addition to immunization, comprehensive screening and antiviral therapy for infected individuals, especially for pregnant women, are crucial strategies to eliminate HBV.

Immune-Escape Mutations Are Prevalent among Patients with a Coexistence of HBsAg and Anti-HBs in a Tertiary Liver Center in the United States.

The concurrent seropositivity of HBsAg and anti-HBs has been described among patients with chronic hepatitis B (CHB), but its prevalence is variable. HBV S-gene mutations can affect the antigenicity of HBsAg. Patients with mutations in the 'α' determinant region of the S gene can develop severe HBV reactivation under immunosuppression. In this study at a tertiary liver center in the United States, we evaluated the frequency and virological characteristics of the HBsAg mutations among CHB patients with the presence of both HBsAg and anti-HBs. In this cohort, 45 (2.1%) of 2178 patients were identified to have a coexistence of HBsAg and anti-HBs, and 24 had available sera for the genome analysis of the Pre-S1, Pre-S2, and S regions. The frequency of mutations in the S gene was significantly higher among those older than 50 years (mean 8.5 vs. 5.4 mutations per subject, p = 0.03). Twelve patients (50%) had mutations in the 'α' determinant region of the S gene. Mutations at amino acid position 126 were most common in eight subjects. Three had a mutation at position 133. Only one patient had a mutation at position 145-the classic vaccine-escape mutation. Despite the universal HBV vaccination program, the vaccine-escape mutant is rare in our cohort of predominantly Asian patients.

Clinical and Economic Burden of Antibiotic Use Among Pediatric Patients With Varicella Infection in the Outpatient Setting: A Retrospective Cohort Analysis of Real-world Data in France.

Varicella infects 90% of children before age 9. Though varicella is self-limiting, its complications may require antibiotics, though how antibiotics are utilized for varicella in France is not well known. This study assessed antibiotic use and costs associated with varicella and its complications in pediatric patients managed in the outpatient setting in France. A retrospective cohort study using the Cegedim Strategic Data-Longitudinal Patient Database, an electronic medical record database from general practitioners and office-based specialists in France, was conducted. Children <18 years old diagnosed with varicella between January 2014 and December 2018 with 3-month follow-up available were included. We used descriptive analysis to assess varicella-related complications, medication use, healthcare resource utilization and costs. Overall, 48,027 patients were diagnosed with varicella; 15.3% (n = 7369) had ≥1 varicella-related complication. Antibiotics were prescribed in up to 25.1% (n = 12,045/48,027) of cases with greater use in patients with complications (68.1%, n = 5018/7369) compared with those without (17.3%, n = 7027/40,658). Mean medication and outpatient varicella-related costs were €32.82 per patient with medications costing a mean of €5.84 per patient; antibiotics contributed ~23% to total costs annually. This study showed high antibiotic use for the management of varicella and its complications. A universal varicella vaccination program could be considered to alleviate complications and associated costs in France.

Prophylactic vaccination in children with mastocytosis

Prophylactic vaccination is one of the fundamental elements of health policy. Poland has a universal vaccination programme, which is systematically modified depending on the changing epidemiological situation of infectious diseases, as well as current medical knowledge, which has its implications in legislation. Mastocytosis is a haematopoietic neoplasm occurring in children, usually with a benign course, limited to the skin and resolving before adolescence. However, the implementation of the general prophylactic vaccination programme in children with mastocytosis raises many concerns among doctors and parents. Vaccinations are among the exogenous agents that may cause mast cell activation and release of biologically active substances, resulting in the exacerbation of mastocytosis symptoms and an increased risk of anaphylaxis. However, the incidence of adverse effects of vaccinations in children with different forms of mastocytosis is in fact comparable to or only slightly higher than in the general population, and vaccine-related events are usually mild and local. Unfortunately, there is a lack of understanding regarding vaccinations in children with mastocytosis both among general practitioners and parents. The aims of this paper are to outline the current state of knowledge on the safety of vaccinations in this group of patients, to promote knowledge related to vaccination in patients with mastocytosis, and to emphasise that mastocytosis is not a contraindication to vaccination.

HBV Vaccines: Advances and Development.

Hepatitis B virus (HBV) infection is a global public health problem that is closely related to liver cirrhosis and hepatocellular carcinoma (HCC). The prevalence of acute and chronic HBV infection, liver cirrhosis, and HCC has significantly decreased as a result of the introduction of universal HBV vaccination programs. The first hepatitis B vaccine approved was developed by purifying the hepatitis B surface antigen (HBsAg) from the plasma of asymptomatic HBsAg carriers. Subsequently, recombinant DNA technology led to the development of the recombinant hepatitis B vaccine. Although there are already several licensed vaccines available for HBV infection, continuous research is essential to develop even more effective vaccines. Prophylactic hepatitis B vaccination has been important in the prevention of hepatitis B because it has effectively produced protective immunity against hepatitis B viral infection. Prophylactic vaccines only need to provoke neutralizing antibodies directed against the HBV envelop proteins, whereas therapeutic vaccines are most likely needed to induce a comprehensive T cell response and thus, should include other HBV antigens, such as HBV core and polymerase. The existing vaccines have proven to be highly effective in preventing HBV infection, but ongoing research aims to improve their efficacy, duration of protection, and accessibility. The routine administration of the HBV vaccine is safe and well-tolerated worldwide. The purpose of this type of immunization is to trigger an immunological response in the host, which will halt HBV replication. The clinical efficacy and safety of the HBV vaccine are affected by a number of immunological and clinical factors. However, this success is now in jeopardy due to the breakthrough infections caused by HBV variants with mutations in the S gene, high viral loads, and virus-induced immunosuppression. In this review, we describe various types of available HBV vaccines, along with the recent progress in the ongoing battle to develop new vaccines against HBV.

Seroprevalence of Anti-SARS-CoV-2 Remained Extremely Low in Taiwan Until the Vaccination Program Was Implemented.

The Taiwanese government made a concerted effort to contain a coronavirus disease 2019 (COVID-19) nosocomial outbreak of variant B.1.429, shortly before universal vaccination program implementation. This study aimed to investigate seroprevalence in the highest-risk regions. Between January and February 2021, we retrieved 10 000 repository serum samples from blood donors to examine for antibodies against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) nucleocapsid (N) and spike (S) antigens. A positive result was confirmed if anti-N and anti-S antibodies were positive. Overall, 2000 donors residing in the highest-risk district and donating blood in January 2021 were further examined for SARS-CoV-2 RNA. We estimated seroprevalence and compared the epidemic curve between confirmed COVID-19 cases and blood donors with positive antibodies or viral RNA. Twenty-one cases with COVID-19 were confirmed in the nosocomial cluster, with an incidence of 1.27/100 000 in the COVID-affected districts. Among 4888 close contacts of the nosocomial cases, 20 (0.4%) became confirmed cases during isolation. Anti-SARS-CoV-2 was detected in 2 of the 10000 blood donors, showing a seroprevalence of 2/10000 (95% CI, 0.55-7.29). None of the 2000 donors who underwent tests for SARS-CoV-2 RNA were positive. The SARS-CoV-2 infection epidemic curve was observed sporadically in blood donors compared with the nosocomial cluster. In early 2021, an extremely low anti-SARS-CoV-2 seroprevalence among blood donors was observed. Epidemic control measures through precise close contact tracing, testing, and isolation effectively contained SARS-CoV-2 transmission before universal vaccination program implementation.

Roll-out of a universal childhood COVID-19 vaccine programme for 12-15 year olds in Northern Ireland

Abstract On 3rd September 2021 the UK Chief Medical Officers (CMOs) jointly published a recommendation that all children aged 12-15 years be offered the COVID-19 vaccine. They concluded that, further to the minimal advantage at individual level for this age group, vaccination would likely help reduce transmission within schools, thus providing a sufficient extra advantage necessary to introduce the programme. In recommending this to Ministers, UK CMOs recognised that the overwhelming benefits of vaccination for adults were not as clear-cut for young people aged 12-15. Children, young people and their parents would need to understand potential benefits, potential side effects and the balance between them. The roll out of the programme had to be undertaken at pace. In NI it was decided that the school setting would be the optimum delivery location as it maximises uptake and reduces inequalities in uptake. A multi-agency project implementation group was formed. The vaccine programme was delivered between October-December 2021, and it brought unique challenges, including; safety concerns around a new vaccine; delays in policy announcements; creation of public and professional resources with complex evidence; anti-vax sentiment and security issues; scale and pace of rollout; and communication with multiple stakeholders. Engagement with schools and teaching unions was crucial, with bespoke support resources developed to aid this. This unique implementation process highlighted the success of the existing school-based vaccine delivery model in NI. It provided opportunities to work closely with education colleagues, and to develop innovative materials for communication of balanced public health messages to a variety of audiences. It also presented unique challenges such as anti-vax discourse and concern around vaccine side-effects. It is unclear if these challenges led to a lower uptake than seen in other school-based vaccine programmes (40.6%). Key messages • The implementation of the COVID-19 vaccine in children aged 12-15 years presented unique challenges however the school-based delivery model was deemed a success. • Further investigation into the uptake is warranted.

Australian Paediatric Surveillance Unit (APSU) Annual Surveillance Report 2022.

For 30 years the Australian Paediatric Surveillance Unit (APSU) has conducted national surveillance of rare communicable diseases and rare complications of communicable diseases. In this report, we describe the results of thirteen such studies surveyed by the APSU in 2022, including reported case numbers and incidence estimates, demographics, clinical features, management and short-term outcomes. Conditions described are: acute flaccid paralysis (AFP); congenital cytomegalovirus (cCMV); neonatal and infant herpes simplex virus (HSV) infection; perinatal exposure to human immunodeficiency virus (HIV) and paediatric HIV infection; severe complications of influenza; juvenile-onset recurrent respiratory papillomatosis (JoRRP); congenital rubella infection/syndrome; congenital varicella syndrome (CVS) and neonatal varicella infection (NVI); and the new conditions dengue; Q fever; and severe acute hepatitis. In 2022, cases of severe complications of influenza were reported to the APSU for the first time since 2019. This likely reflects the easing of government-mandated restrictions imposed in 2020-2021 to curb the transmission of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and the re-emergence of a range of infectious diseases. As previously, AFP surveillance by the APSU contributed to Australia achieving a minimum target incidence of one AFP case per 105 children aged less than 15 years. Cases of JoRRP and NVI were reported in 2022. This indicates potential gaps in human papillomavirus (HPV) and varicella vaccination coverage respectively, especially in high-risk groups such as young migrant and refugee women of childbearing age from countries without universal vaccination programs. Paediatric HIV case numbers resulting from mother-to-child-transmission (MTCT) of HIV remain low in Australia due to use of effective intervention strategies. However, there has been an increase in the number of imported cases of HIV in children (mainly perinatally-acquired) from countries with a high HIV prevalence. Without effective vaccines, there has been no decline in the incidence of congenital CMV and neonatal HSV, indicating the importance of early identification and management to reduce morbidity and mortality. The first cases of dengue, Q fever and severe acute hepatitis were received by APSU in 2022, including two cases of acute hepatitis in which aetiology has not been confirmed to date. The APSU has an important ongoing role in monitoring rare childhood infections.

Past, present, and future of long-term treatment for hepatitis B virus.

The estimated world prevalence of hepatitis B virus (HBV) infection is 316 million. HBV infection was identified in 1963 and nowadays is a major cause of cirrhosis and hepatocellular carcinoma (HCC) despite universal vaccination programs, and effective antiviral therapy. Long-term administration of nucleos(t)ide analogues (NA) has been the treatment of choice for chronic hepatitis B during the last decades. The NA has shown a good safety profile and high efficacy in controlling viral replication, improving histology, and decreasing the HCC incidence, decompensation, and mortality. However, the low probability of HBV surface antigen seroclearance made necessary an indefinite treatment. The knowledge, in recent years, about the different phases of the viral cycle, and the new insights into the role of the immune system have yielded an increase in new therapeutic approaches. Consequently, several clinical trials evaluating combinations of new drugs with different mechanisms of action are ongoing with promising results. This integrative literature review aims to assess the knowledge and major advances from the past of hepatitis B, the present of NA treatment and withdrawal, and the future perspectives with combined molecules to achieve a functional cure.

Epidemiology and Genetic Diversity of Hepatitis B Virus and Hepatitis Delta Virus Infection in Indigenous Communities in Colombia.

Despite the universal vaccination program, there are still regions and territories with a high prevalence of Hepatitis B Virus infection (HBV), such as the Amazon basin, where several indigenous communities live. Additionally, Hepatitis Delta Virus (HDV) is a defective that requires the hepatitis B surface antigen (HBsAg) for the assembly and release of de novo viral particles. Therefore, hepatitis D could be the result of HBV/HDV coinfection or HDV superinfection in individuals with chronic hepatitis B. Among the high prevalence HDV populations are indigenous communities of America. This study aims to describe and characterize the frequency of HBV and HDV infection, viral genotypes and HBV immune escape mutants in indigenous populations from different regions of Colombia. The diagnosis of hepatitis B and hepatitis D was confirmed by serological markers. Moreover, the HBV and HDV genome were amplified by PCR and RT-PCR, respectively, and, subsequently, the phylogenetic analysis was performed. We characterized 47 cases of chronic hepatitis B, 1 case of reactivation and 2 cases of occult hepatitis B infection (OBI). Furthermore, a high prevalence of HDV infection was identified in the study population (29.33%, 22/75) and the circulation of several HBV genotypes and subgenotypes (F1b, F3, F4, and D). Interestingly, this is the first report of the HDV genotype I circulation in this country. These findings demonstrated that HBV and HDV infections are still public health problems in indigenous communities in Colombia.

Molecular epidemiology of pneumococcal carriage in children from Seville, following implementation of the PCV13 immunization program in Andalusia, Spain

IntroductionThe 13-valent pneumococcal conjugate vaccine (PCV13) universal vaccination programme was introduced in December 2016 in Andalusia. MethodsA cross-sectional study was conducted on the molecular epidemiology of pneumococcal nasopharyngeal colonization. A total of 397 healthy children were recruited from primary healthcare centres in Seville for the periods 1/4/2018 to 28/2/2020 and 1/11/2021 to 28/2/2022 (PCV13 period). Data from a previous carriage study conducted among healthy and sick children from 1/01/2006 to 30/06/2008 (PCV7 period), were used for comparison of serotype/genotype distributions and antibiotic resistance rates. ResultsOverall, 76 (19%) children were colonized with S. pneumoniae during the PCV13 period and there were information available from 154 isolates collected during the PCV7 period. Colonization with PCV13 serotypes declined significantly in the PCV13 period compared with historical controls (11% vs 38%, p = 0.0001), being serotypes 19F (8%), 3 (1%) and 6B (1%) the only circulating vaccine types. Serotypes 15B/C and 11A were the most frequently identified non-PCV13 serotypes during the PCV13 period (14% and 11%, respectively); the later one increased significantly between time periods (p = 0.04). Serotype 11A was exclusively associated in the PCV13 period with ampicillin-resistant variants of the Spain9V-ST156 clone (ST6521 and genetically related ST14698), not detected in the preceding period. ConclusionsThere was a residual circulation of vaccine types following PCV13 introduction, apart from serotype 19F. Serotype 11A increased between PCV13 and PCV7 periods due to emergence and clonal expansion of ampicillin-resistant genotype ST6521.

Hepatitis B virus-induced hepatocellular carcinoma: a persistent global problem.

Hepatitis B virus (HBV) infections are highly prevalent globally, representing a serious public health problem. The diverse modes of transmission and the burden of the chronic carrier population pose challenges to the effective management of HBV. Vaccination is the most effective preventive measure available in the current scenario. Still, HBV is one of the significant health issues in various parts of the globe due to non-response to vaccines, the high number of concealed carriers, and the lack of access and awareness. Universal vaccination programs must be scaled up in neonates, especially in the developing parts of the world, to prevent new HBV infections. Novel treatments like combinational therapy, gene silencing, and new antivirals must be available for effective management. The prolonged infection of HBV, direct and indirect, can promote the growth of hepatocellular carcinoma (HCC). The present review emphasizes the problems and probable solutions for better managing HBV infections, causal risk factors of HCC, and mechanisms of HCC.

Economic assessment of childhood rotavirus vaccination in Bangladesh

Rotavirus is one of the most highly prevalent communicable diseases in Bangladesh. The objective of this study is to evaluate the benefit-cost ratio of childhood rotavirus vaccination program in Bangladesh. A spreadsheet-based model was used to estimate the benefit and cost of a nationwide universal rotavirus vaccination program against rotavirus infections among under-five children in Bangladesh. A benefit-cost analysis was performed to evaluate a universal vaccination program compared with a status quo. Data from various published vaccination-related studies and public reports were used. The introduction of a childhood rotavirus vaccination program in Bangladesh for 14.78 million under-five children is projected to prevent approximately 1.54 million rotavirus cases during the first 2 years including 0.7 million severe rotavirus infections. This study shows that among the WHO-prequalified rotavirus vaccines, the net societal benefit is the highest if the vaccination program adopts ROTAVAC® rather than Rotarix® or ROTASIIL®. For every dollar invested in the outreach-based ROTAVAC® vaccination program, society would gain $2.03 in return, while in a facility-based vaccination program, society would gain up to about $2.2. The findings of this study demonstrate that a universal childhood rotavirus vaccination program is a cost-beneficial investment of public money. Thus, the government should consider the introduction of rotavirus vaccination in their Expanded Program on Immunization since the rotavirus immunization policy in Bangladesh will be economically justifiable.

Trend in the Numbers of Hospitalized Patients With Varicella, Herpes Zoster, and Ischemic Stroke in Japanese Individuals

Several studies have shown an association between varicella-zoster virus infection and ischemic stroke. We analyzed the trends in the numbers of patients with varicella, herpes zoster and ischemic stroke before and after the universal vaccination program using a Japanese database of hospitalized patients. The number of patients with varicella decreased but those of herpes zoster and ischemic stroke did not change.

Adverse Events Following Immunizations in Infants Under 1 Year of Age in Lorestan Province, Western Iran.

Vaccination is an important intervention for preventing disease and reducing disease severity. Universal vaccination programs have significantly reduced the incidence of many dangerous diseases among children worldwide. This study investigated the side effects after immunization in infants under 1 year of age in Lorestan Province, western Iran. This descriptive analytical study included data from all children <1 year old in Lorestan Province, Iran who were vaccinated according to the national schedule in 2020 and had an adverse event following immunization (AEFI). Data were extracted from 1084 forms on age, sex, birth weight, type of birth, AEFI type, vaccine type, and time of vaccination. Descriptive statistics (frequency, percentage) were calculated, and the chi-square test and Fisher exact test were used to assess differences in AEFIs according to the abovelisted variables. The most frequent AEFIs were high fever (n=386, 35.6%), mild local reaction (n=341, 31.5%), and swelling and pain (n=121, 11.2%). The least common AEFIs were encephalitis (n=1, 0.1%), convulsion (n=2, 0.2%), and nodules (n=3, 0.3%). Girls and boys only showed significant differences in mild local reactions (p=0.044) and skin allergies (p=0.002). The incidence of lymphadenitis (p<0.001), severe local reaction (p<0.001), mild local reaction (p=0.007), fainting (p=0.032), swelling and pain (p=0.006), high fever (p=0.005), and nodules (p<0.001) showed significant differences based on age at vaccination. Immunization is a fundamental public health policy for controlling vaccine-preventable infectious diseases. Although vaccines such as the Bacillus Calmette-Guérin vaccine, oral poliovirus vaccine, and pentavalent vaccine are well-researched and reliable, AEFIs are inevitable.

The Influence of the Pandemic on Decisions Occuring During the Last Few Years

The notion that present value of cash flows is often improperly estimated in financial models concerning capital improvements and abandonments is a fundamental problem in decision analysis in management and associated decisions and affects estimation of and valuation of intellectual property. Previous studies indicate the usefulness of estimation theory in financial in financial accounting. During the Covid Pandemic of the past few years decisions by governmental and health authorities in the United States and the World were often dictatated during the Pandemic by short-term political influences which included disinformation by some who wished to rake advantage of the misuse of the health Pandemic for political gain and/or financial power and short-term financial gain. Previously this was show to be true as the media with the aid of self-promotional activities by many who were attempting this kind of gain. Furthermore the Pandemic in the United States and other nations is receding in drfamatic ways and many restrictions of the Endemic era are nolonger in use. This was the result of Mask restrictions and increasing but not universal vaccine programs many states and nations.

Epidemiología molecular de la colonización nasofaríngea neumocócica en niños de Sevilla, tras la implementación del programa de vacunación con VNC13 en Andalucía (España)

BackgroundThe 13-valent pneumococcal conjugate vaccine (PCV13) universal vaccination program was introduced in December 2016 in Andalusia. MethodsA cross-sectional study was conducted on the molecular epidemiology of pneumococcal nasopharyngeal colonization. A total of 397 healthy children were recruited from primary healthcare centres in Seville for the periods 1/4/2018 to 28/2/2020 and 1/11/2021 to 28/2/2022 (PCV13 period). Data from a previous carriage study conducted among healthy and sick children from 1/01/2006 to 30/06/2008 (PCV7 period) were used for comparison of serotype/genotype distributions and antibiotic resistance rates. ResultsOverall, 76 (19%) children were colonized with S. pneumoniae during the PCV13 period and there were information available from 154 isolates collected during the PCV7 period. Colonization with PCV13 serotypes declined significantly in the PCV13 period compared with historical controls (11 vs. 38%, P=0.0001), being serotypes 19F (8%), 3 (1%) and 6B (1%) the only circulating vaccine types. Serotypes 15B/C and 11A were the most frequently identified non-PCV13 serotypes during the PCV13 period (14% and 11%, respectively); the later one increased significantly between time periods (P=0.04). Serotype 11A was exclusively associated in the PCV13 period with ampicillin-resistant variants of the Spain9V-ST156 clone (ST6521 and genetically related ST14698), not detected in the preceding period. ConclusionsThere was a residual circulation of vaccine types following PCV13 introduction, apart from serotype 19F. Serotype 11A increased between PCV13 and PCV7 periods due to emergence and clonal expansion of ampicillin-resistant genotype ST6521.

Effectiveness of quadrivalent HPV vaccination in reducing vaccine-type and nonvaccine-type high risk HPV infection.

This study aimed to assess human papillomavirus (HPV) vaccine effectiveness (VE) against both vaccine-type and nonvaccine-type high-risk HPV (hrHPV) infection, and duration of protection in United States. The study population was female participants aged 18-35 years with an HPV vaccination history and genital testing for HPV from the National Health and Nutrition Examination Survey, 2007-2016. Participants vaccinated before sexual debut were assessed against 13 nonvaccine-type hrHPV infection including 31/33/35/39/45/51/52/56/58/59/68/73/82. Multivariable logistic regression was used to estimate VE overall, by age at diagnosis, time since vaccination and lifetime sexual partners. A total of 3866 women were included in the analysis, with 23.3% (95% CI 21.3%-25.4%) having been vaccinated (≥1 dose). VE against vaccine-type HPV18/16/11/6 infection was 58% overall, which was mainly driven by those aged 18-22 years (VE = 64%) and 23-27 years (65%). Among participants aged 18-22 years vaccinated before sexual debut, the VE was 47% (23%-64%) against 13 nonvaccine-type hrHPV and 61% (95% CI 36%-77%) against 5 selected nonvaccine-type hrHPV35/39/52/58/59. Both direct effectiveness and cross-protection maintained effective for 5-10 years post vaccination. We also found the prevalence of ever diagnosed cervical cancer among vaccinated was significantly lower (0.46%, 4/874) than that among unvaccinated participants (1.27%, 38/2992). These findings highlight the potential of significant reduction of cervical cancer following the universal HPV vaccination programme.

Cost-benefit analysis of rotavirus vaccine included in the national immunization program in China.

Globally, rotavirus is a leading cause of severe acute gastroenteritis among children aged under 5years and has a significant economic cost. Currently, rotavirus vaccines are only included in the private market in China. This study aimed to assess the cost-benefit of including a three-dose rotavirus vaccine in China's National Immunization Program (NIP). A decision tree Markov model was constructed to evaluate the cost-benefit of universal immunization with three doses of rotavirus vaccine for a 2019 birth cohort of Chinese children. Costs of the universal vaccination program included vaccine price, vaccine wastage, vaccine administration, and indirect costs. All costs were discounted at 3% per year and converted from 2019 Chinese Yuan to 2019 USD using the 2019 exchange rate. For the 2019 birth cohort of Chinese infants, inclusion of RotaTeq in NIP was estimated to prevent 5,677,911 cases of rotavirus infection, with net savings of $1.1 billion in total societal costs. A cost of $17.55 per vaccine dose was the threshold at which inclusion of rotavirus vaccine in NIP would be cost-saving. Introducing rotavirus vaccine into the China NIP would have significant costs from a societal perspective at the current private market price.

1240. Hepatitis A in Latin America and the Caribbean: a Systematic Literature Review on Endemicity Patterns and Immunization Programs

Abstract Background In 2019, hepatitis A virus (HAV) infections caused around 39,600 deaths worldwide. Age-specific seroprevalence is used as a marker to classify endemicity. In countries with intermediate endemicity, WHO recommends universal HAV vaccination for children ≥1 year considering local disease burden and cost-effectiveness analyses. This review aimed to describe the endemicity patterns and HAV immunization programs in Latin America and the Caribbean (LAC). Methods We conducted a systematic literature review using MEDLINE, Embase, CENTRAL, CDRS, Lilacs, and Scopus from January 2005 to December 2021. Additionally, we searched grey literature, including Pan American Health Organization/WHO country profiles and official government websites in January 2022. The main outcomes were HAV seroprevalence and characteristics of HAV immunization programs. Results We identified 30 studies containing data on HAV seroprevalence in LAC and 13 records from grey literature on HAV vaccination program. As of January 2022, among 33 countries, 8 had public universal childhood HAV vaccination program and 12 had programs for at least one population at-risk (Figure 1 and Table 1). Only 7 countries had seroprevalence data available (Figure 2). Using WHO criteria, 5 countries were classified as intermediate endemicity; 2 have already introduced HAV vaccination in the NIP (Brazil and Colombia) and 3 have not introduced yet (Bolivia, Mexico, and Peru). In Argentina and Brazil, studies conducted in certain populations at risk, such as men who have sex with men and healthcare workers aged between 20-40 years, showed higher susceptibility to infection (seroprevalence: 40%-60%). Figure 1.Hepatitis A routine immunization schedule in national immunization programs in Latin America and the Caribbean, 2022 a Available for Guatemalan Social Security Institute (employed people in formal sector), which represents 17% of total population. b Countries that included in national immunization program for at least one population at risk Table 1.Characteristics of hepatitis A immunization programs in Latin America and the Caribbeana Populations at risk: 2-dose schedule; b Partial introduction in 2014 in endemic areas; c only available for Guatemalan Social Security Institute (formally employed population), which represents 17% of total populationFigure 2.Hepatitis A endemicity level in studies conducted in Latin America and the Caribbean based on WHO classification criteriaa general population; b premarital exam; c health care workers; d children school; e liver cirrhosis; f national survey; g samples from labs, h beauticians; i population-based survey; j chronic HCV infection; k rural settlement; l low socioeconomic groups; m chronic HCV infection; n men who have sex with men/ transgender women. Mantovani 2015 and Pereira 2016 are included in the review and not showed here (description of prevalence &amp;lt; 5 y) Conclusion Eight countries had universal HAV vaccination program and 12 offered for at least one population at-risk. LAC countries where HAV seroprevalence was available showed predominance of intermediate endemicity. Bolivia, Mexico, and Peru would benefit from universal childhood vaccination, and Argentina and Brazil should evaluate increasing susceptibility among adults at-risk to expand access to vaccination. In countries without recent data, surveillance of acute cases/outbreaks and seroprevalence studies are needed to guide the HAV vaccination implementation. Disclosures Cintia I. Parellada, MD, PhD, MSD Brazil: Employee of MSD Brazil, a subsidiary of Merck &amp; Co., Inc.,|MSD Brazil: Stocks/Bonds Emilia Prieto, MD, MSc, MSD Colombia: Employee of MSD Colombia, a subsidiary of Merck &amp; Co., Inc.,|MSD Colombia: Stocks/Bonds Cristina Carias, PhD, Merck &amp; Co., Inc.: Employee|Merck &amp; Co., Inc.: Stocks/Bonds Martha Carolina Valderrama, MD, Msc, IQVIA: Advisor/Consultant|IQVIA: Employee of IQVIA who received funding to execute this study Daniel Samacá-Samacá, Msc, IQVIA: Advisor/Consultant|IQVIA: Employee of IQVIA who received funding to execute this study Fabian Hernandez, BSPharm, Msc, IQVIA: Employee of IQVIA who received funding to execute this study Homero Monsanto, PhD, Merck &amp; Co., Inc.: Employee.