Hepatitis A Virus Vaccination Research Articles

Seropositivity of hepatitis A and E viruses in patients attending a tertiary care center in central India

Objectives: Hepatitis A virus (HAV) and hepatitis E virus (HEV) infections are significant global health concerns that contribute to acute viral hepatitis. This study aimed to investigate the prevalence of HAV, HEV, and co-infections in a tertiary care hospital setting in central India. Materials and Methods: This retrospective observational study analyzed 987 clinical specimens collected from suspected acute viral hepatitis cases over 5 years (2019–2023). Commercially available enzyme-linked immunosorbent assay kits were used to detect HAV and HEV immunoglobulin M antibodies. Statistical analysis: Demographic data and clinical information were collected and analyzed using Chi-square tests. P < 0.05 was considered statistically significant, indicating a significant association between the variables under investigation. Results: Overall, 32.72% of patients were seropositive for either HAV, HEV, or both. The prevalence of HAV was 22.9%, HEV was 9.83%, and co-infection was 3.24%. HAV infection was more prevalent in children (0–14 years), whereas HEV was more prevalent in adults. Both HAV and HEV infections were associated with elevated liver function markers, with the highest levels observed in co-infected cases. The monsoon season had the highest number of cases. Conclusions: This study revealed a substantial burden of HAV, HEV, and co-infections in central India. The observed sex—and age-specific prevalence patterns warrant further investigation. Effective public health strategies addressing sanitation, hygiene practices, and HAV vaccination programs are crucial to reducing the disease burden.

Hepatitis A vaccine immunogenicity among seronegative liver transplanted children.

The hepatitis A virus (HAV) vaccine is highly immunogenic in general, yet data on its use in liver-transplanted (LT) children is limited. This study aimed to determine the seroimmunity to HAV in all LT children, and the immunogenicity of an inactivated HAV vaccine in seronegative LT children at King Chulalongkorn Memorial Hospital. Seronegative LT children received the inactivated HAV vaccine at 0 and 6-8months with adverse events monitored for 3days post-immunization. The result reviewed that among 105 LT children, vaccination records were available for 81%, of which 7.1% and 16.5% with one and two doses of HAV vaccine were immunized before transplantation, respectively. Post-transplantation, 20.1% were seropositive for HAV, with 9.5% due to pre-transplant immunization. Eighty-three seronegative LT children (aged 7.25 ± 4.40years; 48.6% male) received two vaccine doses. The seropositive rate increased following the first and second doses and reached to 51.5%, and 92.9%, respectively (p < 0.001), with no serious adverse events reported. Age at vaccination and the interval from transplantation to vaccination were risk factors for non-responsiveness (p < 0.001). The study highlighted inadequate HAV vaccination coverage, leaving most LT children susceptible to infection. HAV vaccine proved highly immunogenic and safe, emphasizing the need for improved vaccination strategies before and after liver transplantation.Trial registration TCTR20220110001.

Viral hepatitis in persons living with HIV in the post-COVID era.

Coinfection with hepatitis viruses A to E is frequent in persons living with HIV (PLWH) and causes significant morbidity and mortality. Oro-fecal transmissible hepatitis A and E mostly produce acute self-limited episodes in poor income regions and in non-vaccinated travelers. In high-income countries, outbreaks of hepatitis A occur in men having sex with men (MSM) and chronic hepatitis E is occasionally reported among PLWH with severe immunodeficiency. Chronic hepatitis B, C, and D are frequent in PLWH in highly endemic regions and globally in persons who inject drugs (PWID) and MSM. Progression to liver cirrhosis and development of hepatocellular carcinoma (HCC) is major clinical complications in coinfected patients. Current estimates for PLWH are of 38 million worldwide. Roughly 12% have chronic viral hepatitis (5 million). Coinfection figures are of 5-10% for HBV (2-4 million), 4% for HCV (1.5 million), and 15% of HBsAg+ for HDV (0.5 million). Oral direct-acting antivirals (DAA) cure almost all treated patients with hepatitis C. However, given that there is no protective HCV immunity, PLWH with high-risk behaviors may experience HCV reinfection episodes. Tenofovir is the drug of choice in PLWH with chronic hepatitis B, given its dual effect on HIV and HBV. Lifelong oral tenofovir suppresses HBV replication and ameliorate liver damage. However, the risk of HCC persists even in the absence of cirrhosis. Finally, HDV causes the worst of viral hepatitis with faster progression to cirrhosis and HCC. An entry inhibitor, bulevirtide, has recently been approved and another drug, lonafarnib, is completing Phase 3 trials. Combination antiviral therapy for hepatitis D could improve dramatically the poor prognosis of HIV-HDV coinfected patients. The resumption of good medical practices in PLWH after the big disruption caused by COVID-19 will reduce the burden of viral hepatitis coinfections. Renewed efforts on HAV and HBV vaccination of susceptible individuals and earlier and wider prescription of antiviral therapy for HBV, HCV, and/or HDV coinfection should be prioritized in PLWH. The benefits of innovative strategies for viral hepatitis, including pre-exposure prophylaxis or use of long-acting antivirals, warrant further consideration in PLWH.

The Immunological and Epidemiological Effectiveness of Pediatric Single-Dose Vaccination against Hepatitis A 9 to 11 Years after Its Implementation in the Tyva Republic, the Russian Federation.

Since 2012, universal single-dose HAV vaccination in children aged 3 years and older has been implemented in the Tyva Republic, a region of the Russian Federation. The aim of this prospective non-interventional observational single-center study was to determine the immunological and epidemiological effectiveness of single-dose vaccination against hepatitis A 9 to 11 years after its implementation. The anti-HAV IgG antibodies were determined in two independent cohorts of children who were vaccinated with a single dose of monovalent pediatric inactivated vaccine (HAVRIX® 720 EU) in Tyva in 2012 and recruited 9 years (Year 9 Cohort) and 11 years (Year 11 Cohort) after immunization. The seroprotection rates defined as anti-HAV antibody concentrations ≥10 mIU/mL reached 99.4% (95% CI: 98.2-99.9% [501/504]) in the Year 9 Cohort, but decreased significantly to 75.4% (95% CI: 73.0-77.6% [1006/1335]) in the Year 11 Cohort (p < 0.0001). The anti-HAV geometric mean concentrations decreased from 1446.3 mIU/mL (95% CI: 1347.1-1545.4 mIU/mL) in the Year 9 Cohort to 282.6 mIU/mL (95% CI: 203.8-360.8, p < 0.0001) in the Year 11 Cohort. The HAV vaccination program resulted in zero rates of hepatitis A incidence in the Tyva Republic since 2016. However, the limited monitoring of HAV RNA in sewage and environmental samples demonstrated the ongoing circulation of both the regional epidemic strain of HAV genotype IA and another genotype IA strain imported recently from other parts of the Russian Federation, probably due to subclinical infections in non-vaccinated children under 3 years of age. Taken together, these data indicate the effectiveness of the single-dose HAV vaccination strategy but suggest the need to expand the vaccination program to include children aged 12 months and older to achieve maximum effectiveness.

Cellular immune response to a single dose of live attenuated hepatitis a virus vaccine in obese children and adolescents

BackgroundLimited data are currently available regarding the cellular immune response to a live attenuated hepatitis A virus (HAV) vaccine, especially in children with obesity. The objective of this retrospective cohort study was to compare the activation of antigen-specific interferon (IFN)-γ+ T cells in obese children and adolescents with healthy individuals before and after immunization with a single dose of live attenuated HAV vaccine. MethodsBlood samples were obtained from the 2021 study by Dumrisilp et al. investigating the immunogenicity of the live attenuated hepatitis A vaccine in children and young adults. Prior to enrollment, all 212 subjects had never received any HAV vaccine and tested negative for anti-HAV antibodies. The participants were vaccinated with a freeze-dried, live attenuated HAV vaccine of the H2 strain. In this study, we analyzed the stored peripheral blood mononuclear cells (PBMCs) obtained from a subgroup of 30 obese subjects and 30 normal-weight healthy controls of the same age and sex. PBMCs were collected before and 8–9 weeks after HAV vaccination for further analysis. These cells were stimulated with a recombinant antigen derived from HAV-VP3, and the immune response was evaluated using the IFN-γ enzyme-linked immunospot (ELISpot) assay. ResultsThe between-group analysis indicated that the T-cell response of obese participants was comparable to that of normal-weight controls both before and after vaccination. The change in IFN-γ production from before to after vaccination in the obese group was not significantly different from that of the control group. Additionally, in the obese group, no correlation was found between IFN-γ production and clinical characteristics such as sex, body mass index, waist circumference, and acanthosis nigricans. ConclusionTesting for cellular immune response provides a comprehensive understanding of the overall immune response to vaccination. This study, the first to explore this significant aspect, suggests that obesity does not affect the short-term cellular immune response to live attenuated HAV vaccination.

Global burden of vaccine-associated rheumatic diseases and their related vaccines, 1967-2023: A comprehensive analysis of the international pharmacovigilance database.

Vaccine-associated rheumatic diseases are rare but one of the most feared adverse drug reactions (ADRs). However, this topic has been investigated less with large-scale data in the literature. With the rapid progress in the development and approval of vaccines during the pandemic, public concerns regarding their safety have been raised. To assess the global and regional burden, long-term trends, and potential risk factors of vaccines-associated six types of rheumatic diseases (ankylosing spondylitis [AS], polymyalgia rheumatica [PMR], rheumatoid arthritis [RA], Sjögren's syndrome, Systemic lupus erythematosus [SLE], Systemic scleroderma), this study conducted disproportionality analysis based on the reports from the World Health Organization International Pharmacovigilance Database documented between 1967 and 2023 (n for total reports = 131 255 418) across 156 countries and territories. We estimated the reporting odds ratio (ROR) and information component (IC) to determine the disproportionality signal for rheumatic diseases. Of 198 046 reports of all-cause rheumatic diseases, 14 703 reports of vaccine-associated rheumatic diseases were identified. While the reporting counts have gradually increased over time globally, we observed a dramatic increase in reporting counts after 2020, potentially due to a large portion of reports of COVID-19 mRNA vaccine-associated rheumatic diseases. The disproportionality signal for rheumatic diseases was most pronounced in HBV vaccines (ROR, 4.11; IC025, 1.90), followed by COVID-19 mRNA (ROR, 2.79; IC025, 1.25), anthrax (ROR, 2.52; IC025, 0.76), papillomavirus (ROR, 2.16; IC025, 0.95), encephalitis (ROR, 2.01; IC025, 0.58), typhoid (ROR, 1.91; IC025, 0.44), influenza (ROR, 1.49; IC025, 0.46), and HAV vaccines (ROR, 1.41; IC025, 0.20). From age- and sex-specific perspective, young females and old males are likely to have vaccine-associated rheumatic disease reports. Furthermore, overall vaccines showed a disproportionality signal for PMR (IC025, 3.13) and Sjögren's syndrome (IC025, 0.70), systemic scleroderma (IC025, 0.64), specifically while the COVID-19 mRNA vaccines are associated with all six types of diseases. Although multiple vaccines are associated with rheumatic disease reports, healthcare providers should be aware of the potential of autoimmune manifestations following vaccination, particularly the COVID-19 mRNA and HBV vaccines, and take into account for risk factors associated with these ADRs. Most ADRs exhibited an average time to onset of 11 days, underscoring the significance of monitoring and timely management by clinicians.

Hepatitis A in Latin America: The current scenario.

This review aims to gather and disseminate updated information regarding hepatitis A virus (HAV) in Latin America (LA) in the last 11years, including seroprevalence, post-vaccination studies, virus detection in aqueous matrices and food samples, and outbreak reports. Only 24 seroprevalence studies were published between 2012 and 2023 with 55%-100% reported prevalences of anti-HAV IgG. Among the 25 LA countries, only eight of them have introduced HAV vaccines into their immunisation programs. Outbreaks of hepatitis A occurred between 2017-2019, mainly affecting men who have sex with men in Argentina, Brazil and Chile, probably as a consequence of the abrupt decline of young adults' immunity. This could be due to that young adult have never been infected in childhood (due to socio-health improvements) and are above the cut-off ages to be included when the vaccination programs were introduced. Although scarce, studies focused on environmental and food HAV surveillance have shown viral presence in these samples. Surface waters presented HAV detections between 1.2% and 86.7%, and untreated wastewaters between 2.8% and 70.9%. Genotypes found in all cases were IA and IC. The only wastewater-based epidemiology study showed to be a useful tool as a complement of traditional epidemiological surveillance. Only four LA countries have looked for HAV in food samples, with genome detection rates between 9% and 33%. Latin American HAV circulation scenario is changing. In countries where socioeconomic and sanitary conditions have not improved, the virus persists with high endemicity and the access to the vaccine should be re-evaluated by local governments. In countries where access to clean water, better sanitary conditions and HAV immunisation programs have been implemented, the number of cases among young adults seems to be increasing, alerting health authorities.

Sexual and preventive behaviors associated with HAV, HBV, and HPV vaccine hesitancy among men who have sex with men in France

ABSTRACT Vaccination coverage against hepatitis A virus (HAV), hepatitis B virus (HBV), and human papillomaviruses (HPV) is insufficient among men who have sex with men (MSM), partly because of their high prevalence of vaccine hesitancy (VH) specific to these vaccines. This study aimed to investigate determinants of specific VH in MSM, focusing on characteristics of their sexual activity, propensity to use prevention tools and medical care, disclosure of sexual orientation to health care professionals (HCPs), and perceived stigmatization. A cross-sectional electronic survey (February – August 2022) collected perceptions of HBV, HAV, and HPV, and of their respective vaccines among 3,730 French MSM and enabled the construction of a specific VH variable. Using agglomerative hierarchical cluster analysis, we constructed a typology of MSM sexual and prevention practices. We identified three MSM clusters (low- (C1, 24%), moderate- (C2, 41%), and high- (C3, 35%) “sexual activity/medical engagement”) that showed an increasing gradient in the use of medical prevention with regular medical care and exposure to high-risk sexual practices. A multiple ordinal logistic regression showed that overall specific VH was higher in the C1 cluster and in men who had not informed their physician of their sexual orientation. This typology could usefully help to adapt vaccination communication strategies for MSM prevention program according to patients’ profiles. HCPs should be encouraged and trained to ask men about their sexual practices and to provide appropriate vaccination recommendations nonjudgmentally.

Prevalence of HAV IgM marker of Hepatitis A virus among patients of all Ages in Diyala province/Iraq

The most prevalent viral infection that causes hepatitis is hepatitis A virus (HAV), which continues to be a worldwide health issue for both developed and underdeveloped nations. By calculating the rate of HAV IgM positive, the current study sought to determine the prevalence of HAV infections among patients in the province of Diyala. In the present study, a total of 180 blood specimens were collected from patients, who referred to diagnostic individuals in Diyala Province, Iraq from October /2022 till Agust 2023. The presence of HAV in the specimens was investigated using ELISA technique. The results of the current study revealed that the overall positivity rate of HAV IgM was 13.3%. HAV IgM positivity was higher among 1-2 years old group. While, it was insignificantly higher among females compared to males (54.2%). Furthermore, HAV IgM positivity rate was insignificantly higher among Rurales compared to urbans (58.3%, 41.7%). Additionally the results showed that HAV IgM positivity rate among those used unsterilized water (70.8%) was significantly higher than that sterilized water (29.2%). Moreover, the results found that those with un vaccinated with HAV vaccine had significantly higher (79.2%) HAV IgM positivity rate. The present study founded that it is important to increase our knowledge about the frequency of HAV infections among patients and early diagnosis of HAV infections is essential in community for infection control.

Assessing Immunity to Hepatitis A and Hepatitis B Among Individuals in Custody Living With HIV.

Screening upon entry into prison for hepatitis A virus (HAV) and hepatitis B virus (HBV) provides an ideal public health opportunity to offer vaccination to individuals who are nonimmune. We conducted a retrospective review of HAV and HBV immunity among adults living with HIV in the Illinois Department of Corrections between January 1, 2019, and December 31, 2019. The primary objective was to assess rates of HAV and/or HBV immunity in individuals with HIV. In total, 436 people were included in the study. Of 425 patients who had data for HAV vaccination, 335 were immune. Of 421 patients who had data for HBV vaccination, 272 were immune. Of the 149 patients who were nonimmune to HBV, 22 had active HBV and 6 had an equivocal HBV surface antibody and negative HBV surface antigen. In total, 212 (52%) were immune to both HAV and HBV, and 31 (8%) had no immunity to either HAV or HBV. These data demonstrate an important opportunity to discuss and provide vaccination while in custody.

Inactivated TZ84 strain hepatitis A vaccine and its impact: A narrative review

Hepatitis A (HepA) represents a significant global public health challenge. At present, there is no definitive treatment available for managing HepA. Before the availability of HepA vaccines, hepatitis A virus (HAV) infection had emerged as a leading cause of fulminant hepatic failure and a significant indication for liver transplantation in children living in Argentina, Brazil, the Republic of Korea, and India. Inactivated HAV vaccines have demonstrated a high level of immunogenicity. In addition, there is evidence supporting the use of inactivated HepA vaccines in immunocompromised individuals and as post-exposure prophylaxis. Recently, the inactivated TZ84 strain hepatitis A vaccine, which has shown superior immunogenicity for up to 30 years and fewer adverse reactions when compared with other inactivated HepA vaccines, has become available in India. Moreover, the TZ84 strain of the inactivated HAV vaccine has the potential to control community-wide outbreaks. This narrative review offers an overview of the existing evidence concerning immunization against HepA in India, with a particular emphasis on the TZ84 strain of the inactivated HAV vaccine.

Inactivated TZ84 strain hepatitis A vaccine and its impact: A narrative review

Hepatitis A (HepA) represents a significant global public health challenge. At present, there is no definitive treatment available for managing HepA. Before the availability of HepA vaccines, hepatitis A virus (HAV) infection had emerged as a leading cause of fulminant hepatic failure and a significant indication for liver transplantation in children living in Argentina, Brazil, the Republic of Korea, and India. Inactivated HAV vaccines have demonstrated a high level of immunogenicity. In addition, there is evidence supporting the use of inactivated HepA vaccines in immunocompromised individuals and as post-exposure prophylaxis. Recently, the inactivated TZ84 strain hepatitis A vaccine, which has shown superior immunogenicity for up to 30 years and fewer adverse reactions when compared with other inactivated HepA vaccines, has become available in India. Moreover, the TZ84 strain of the inactivated HAV vaccine has the potential to control community-wide outbreaks. This narrative review offers an overview of the existing evidence concerning immunization against HepA in India, with a particular emphasis on the TZ84 strain of the inactivated HAV vaccine.

Viral Hepatitis

Background: The primary goals of conducting surveillance for viral hepatitis are to direct prevention and control activities for these diseases and to evaluate the impact of these activities. Any person with a hepatitis virus infection is a potential source of infection to others. Surveillance would help accomplish the goals by providing information on:&#x0D; &#x0D; Creating a network of laboratories for diagnosis of viral hepatitis. 2. Monitor trends in incidence of and risk factors for disease.&#x0D; Assess burden of disease 4. Identify infected persons requiring counseling and /or post exposure prophylaxis. 5. Identify and control outbreaks.&#x0D; &#x0D; Methodology: Laboratory based targeted sousveillance in sentinel geographical regions/population. Clinical Case Definition: An acute illness with discrete onset of symptoms (e.g., fatigue, abdominal pain, loss of appetite, intermittent nausea, vomiting), and jaundice. (sourcewww.cdc.gov.in) NCDC will be the nodal agency for implementation of the project.&#x0D; Results: HBV, HCV and HDV are transmitted through contaminated blood or blood components or through the use of contaminated needles and syringes. In several populations, a common route of transmission of HBV infection is from infected pregnant women to their infants around the time of delivery. In many people with HBV or HCV infection, no route of transmission can be identified. In addition, specific vaccines and/or passive immune prophylaxis (use of specific immunoglobulin products) are also useful in preventing transmission of some infections. and also HAV vaccine is the most effective method for specific pre-exposure prophylaxis. and two different vaccines based on inactivated cell culture are available. Both vaccines are highly antigenic, especially in adults, and induce protective antibody levels in more than 95% of recipients after the first dose of vaccine. Individuals at high risk of repeated exposure to HBV, such as personnel Health Care Anti-HBs titer should be evaluated one month after the third dose. An Anti-HBs titer of 10 IU/L (or 10 mIU/mL) is protective. After reaching this titer, there is no need for further booster doses.&#x0D; Conclusion: Viral hepatitis is a systemic infection affecting predominantly the liver and causing its inflammation. It may be acute (recent infection, relatively rapid onset) or chronic. Viral hepatitis is caused by infection with one of the five known hepatotropic viruses, which are named as hepatitis A virus (HAV), hepatitis B virus (HBV), hepatitis C virus (HCV), hepatitis D virus (HDV), and hepatitis E virus (HEV), respectively. These viruses are quite divergent in their structure, epidemiology, routes of transmission, incubation period, clinical presentations, natural history, diagnosis, and preventive and treatment options.

Fixing a Hole: a retrospective cohort study evaluating HAV, HBV, tetanus screening, and vaccination during hospitalization in persons who use substances.

Rates of serious injection-related infections in persons who use drugs have increased. Resulting admissions are an opportunity for screening and vaccination of preventable infections such as hepatitis A virus (HAV), hepatitis B virus (HBV), and tetanus. We conducted a retrospective review of adults with documented substance use admitted for bacterial infection between July 2015 and March 2020. We evaluated HAV, HBV, and tetanus vaccination status at admission, along with screening for HAV and HBV infection and immunity. We identified the proportion of patients at risk for infection who received HAV, HBV, and tetanus vaccines during admission and patient-level factors associated with vaccination. We identified 280 patients who met our inclusion criteria. Of the 198 (70.7%) patients at risk for HAV, infectious disease providers recommended vaccination for 21 (10.6%) and 15 (7.6%) received HAV vaccine. Of the 174 (62.1%) patients at risk for HBV, infectious disease providers recommended vaccination for 32 (18.3%) and 25 (14.4%) received HBV vaccine. A large proportion of patients (31.4%, 88) had no documentation of prior tetanus vaccination, and infectious disease providers recommended tetanus vaccination for three (1.1%) and five patients (1.8%) received a tetanus booster. Infectious disease consult vaccine recommendations were statistically significantly associated with HAV or HBV vaccination prior to discharge. Over 70% of our population is at risk for one or more of these preventable infections. Efforts are needed to maximize inpatient screening and vaccination for HAV, HBV, and tetanus in patients with barriers to care.

Modeling hepatitis A epidemiological profiles and estimating the pediatric vaccination threshold in the Russian Federation.

To combat the hesitancy towards implementing a hepatitis A universal mass vaccination (UMV) strategy and to provide healthcare authorities with a comprehensive analysis of the potential outcomes and benefits of the implementation of such a vaccination program, we projected HAV seroprevalence and incidence rates in the total population of the Russian Federation and estimated the pediatric vaccination threshold required to achieve an incidence level of less than 1 case per 100,000 using a new mathematical model. A dynamic age-structured SEIRV (susceptible-exposed-infectious-recovered-vaccinated) compartmental model was developed and calibrated using demographic, seroprevalence, vaccination, and epidemiological data from different regions of the Russian Federation. This model was used to project various epidemiological measures. The projected national average age at the midpoint of population immunity increases from 40 years old in 2020 to 50 years old in 2036 and is shifted even further to the age of 70 years in some regions of the country. An increase of varying magnitude in the incidence of symptomatic HAV infections is predicted for all study regions and for the Russian Federation as a whole between 2028 and 2032, if the HAV vaccination coverage level remains at the level of 2022. The national average vaccination coverage level required to achieve a symptomatic HAV incidence rate below 1 case per 100,000 by 2032 was calculated to be 69.8% if children aged 1-6 years are vaccinated following the implementation of a UMV program or 34.8% if immunization is expanded to children aged 1-17 years. The developed model provides insights into a further decline of herd immunity to HAV against the background of ongoing viral transmission. The current favorable situation regarding hepatitis A morbidity is projected to be replaced by an increase in incidence rates if vaccination coverage remains at the current levels. The obtained results support the introduction of a hepatitis A UMV strategy in the Russian Federation.

Delays in Hepatitis A vaccination in people with HIV in Houston, Texas between 2010 and 2018

BackgroundStudies have demonstrated low hepatitis A virus (HAV) vaccination rates among persons with HIV (PWH). MethodsWe conducted a retrospective study of persons entering HIV care at two clinics in Houston, Texas between 2010 and 2018. We defined those eligible for HAV vaccination as those who had no history of HAV vaccination and had a negative anti-HAV IgG at entry to care. Kaplan-Meier curves summarized time to receipt of HAV vaccines. The proportions of patients who received 1 and 2 HAV vaccines at 6, 12, and 24 months were estimated. Cox proportional hazards regression evaluated associations between patient characteristics and vaccination. Significant factors were included in a multivariable Cox proportional hazards model. ResultsOf 6,515 patients, 1372 were eligible for HAV vaccination. Of eligible patients, 29.2 % received 1 HAV vaccination at 6 months, 37.1 % at 12 months, and 47.8 % at 24 months. At 6 months, 10 % received 2 HAV vaccinations, 21.1 % at 12 months, and 33.4 % at 24 months. In multivariable analysis, men who have sex with men (adjusted HR 1.35, 95 % CI 1.06, 1.73) or those who had CD4 count ≥ 200 cells/µl (adjusted HR 2.52, 95 % CI 1.89, 3.37) had their second vaccination sooner than those who were not men who have sex with men or who had CD4 counts < 200 cells/µl, respectively. Patients > 50 years of age had their second vaccination sooner than those aged 30–50 years (adjusted HR 1.47, 95 % CI 1.08, 1.99). Those with active substance history had a longer time to second vaccination compared to those with no substance use history (adjusted HR 0.57, 95 % CI 0.40, 0.82). ConclusionsHAV vaccination rates were low and highlight the need for effective solutions to address HAV immunization gaps in PWH, especially among young patients, those with active substance use disorders, and those with significant immunocompromise.

Assessing vaccine-induced immunity against pneumococcus, hepatitis A and B over a 9-year follow-up in pediatric liver transplant recipients: A nationwide retrospective study

Pediatric liver transplant recipients are particularly at risk of infections. The most cost-effective way to prevent infectious complications is through vaccination, which can potentially prevent infections due to hepatitis B (HBV) virus, hepatitis A virus (HAV), and invasive pneumococcal diseases. Here, we performed a retrospective analysis of HBV, HAV, and pneumococcal immunity in pediatric liver transplant recipients between January 1, 2009, and December 31, 2020, to collect data on immunization and vaccine serology. A total of 94% (58/62) patients had available vaccination records. At transplant, 90% (45/50) were seroprotected against HBV, 63% (19/30) against HAV, and 78% (18/23) had pneumococcal immunity, but immunity against these 3 pathogens remained suboptimal during the 9-year follow-up. A booster vaccine was administered to only 20% to 40% of patients. Children who had received >4 doses of HBV vaccine and > 2 doses of HAV vaccine pretransplant displayed a higher overall seroprotection over time post-solid organ transplant. Our findings suggest that a serology-based approach should be accompanied by a more systematic follow-up of vaccination, with special attention paid to patients with an incomplete vaccination status at time of transplant.

1801. About Damn Time: HAV, HBV, and Tetanus Screening and Vaccination during Hospitalization in Persons who Use Drugs

Abstract Background Rates of serious injection related infections (SIRI) in persons who use drugs (PWUD) have increased over the past two decades. Admissions for SIRI are an opportunity for screening and vaccination of preventable infections like hepatitis A virus (HAV), hepatitis B virus (HBV) and tetanus given significant barriers to preventive care in the outpatient setting for this population. The purpose of this study was to evaluate rates of screening and subsequent vaccination for hepatitis A, hepatitis B, and tetanus for PWUD admitted to the hospital for treatment of serous bacterial infection. Methods We conducted a retrospective review of adult patients admitted for a bacterial infection requiring &amp;gt; 2 weeks of antibiotics with both infectious disease (ID) and addiction medicine consults. Data on patient demographics, screening recommendations, and testing and vaccination administration were collected via chart review. Results 280 patients were eligible for inclusion. Of the 198 (70.7%) patients determined at risk for HAV, ID recommended vaccination for 21 (10.6%) and 15 (7.6%) received HAV vaccine during the admission. Of the 174 (62.1%) patients at risk for HBV, ID recommended vaccination for 32 (18.3%) and 25 (14.4%) received HBV vaccine prior to discharge. 88 patients (31.4%) had no documentation of prior tetanus vaccination and ID recommended tetanus vaccination for 3 (1.1%). 5 patients (1.8%) received a tetanus booster during admission. In univariable analysis, the strongest factor associated with HAV (Odds Ratio 142.19, 95% Confidence Interval: 27.34-739.44) and HBV (Odds Ratio 18.98, 95% Confidence Interval: 7.02-51.37) vaccination during admission was ID recommendation for vaccine. Conclusion Screening and vaccination for HAV and HBV remains low in the inpatient setting, as does tetanus vaccination in high-risk patients. A large proportion of our population (70%) were at risk for one or more of these preventable infections. Given the limited access and significant barriers to healthcare in this vulnerable population, efforts should be taken to maximize inpatient screening and vaccination for HAV, HBV, and tetanus. Disclosures Monica K. Sikka, MD, F2G: Grant/Research Support

Hepatitis A outbreak in a refugee shelter in Kiel, northern Germany.

In the spring of 2023, three Ukrainian war refugees from a municipal community shelter and a volunteer caregiver at an affiliated daycare center in Kiel, Germany, were diagnosed with infectious jaundice attributable to a single hepatitis A virus (HAV) subgenotype IA strain. Similar HAV sequences have been observed in Germany and other European countries for several years. One refugee and the volunteer required hospitalization. Four children were asymptomatically infected but excreted high levels of HAV ribonucleic acid in the stool. The infections were probably acquired in Germany, but a source could not be determined. The outbreak was contained through vaccination, increased hygiene, and education. The existing HAV vaccination recommendation for refugee shelter staff and volunteers should be consistently implemented.

Seroprevalence of hepatitis A virus antibodies among children and adolescents living in Northern Thailand: an implication for hepatitis A immunization

This cross-sectional study aimed to assess seroprevalence of hepatitis A virus (HAV) antibodies and identify factors associated with HAV seropositivity among children and adolescents aged 1–18 years who resided in Chiang Mai, Thailand. Sociodemographic characteristics, sanitation/hygiene, and history of HAV vaccination were collected. Anti-HAV IgG antibody was determined, and a level ≥ 1.0 S/CO defined HAV seropositivity. We enrolled 300 participants; median age 8.7 years, 54% male, and 13% overweight (BMI z-score: + 1 to + 2 standard deviation [SD]). Sixty-five participants (22%) were vaccinated against HAV. Overall, 84/300 participants (28%) demonstrated HAV seropositivity, of whom 55/65 (85%) and 29/235 (12%) were among vaccinated and unvaccinated participants (P < 0.001), respectively. Previous HAV vaccination (adjusted odds ratio [aOR] 47.2; 95% CI 20.0–111.8) and overweight (aOR 4.4; 95% CI 1.7–11.3, compared with normal weight [BMI z-score: − 2 to + 1 SD]) were significantly associated with seropositivity of HAV. In the stratified analyses, crowded bedroom (aOR 3.2; 95% CI 1.3–7.8, per one person increase) and overweight (aOR 5.0; 95% CI 1.8–13.7) were factors associated with HAV seropositivity among vaccinated and unvaccinated participants, respectively. Seroprevalence of HAV antibodies in healthy Thai children and adolescents was relatively low. Recommendation of HAV vaccination for these populations, particularly those with high-risk conditions, should be considered.