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

Background: 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. Methods: 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. Results: 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. Conclusion: 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.

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 11 years, 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.

Antibody persistence 7 years after hepatitis-A vaccine in children with human immunodeficiency virus infection.

BACKGROUND: HIV-infected children have a higher risk of presenting infections, including the hepatitis A virus (HAV). The inactivated HAV vaccine is immunogenic in immunocompetent hosts; however, there are insufficient studies on the duration of seroprotection in HIV-infected children. METHODS: An analytical cohort study was conducted. HIV-1-infected children who received the inactivated HAV vaccine (2 doses) were included. Blood samples were taken for antibody measurement, the first one 28 days after the second dose and another 7 years after the vaccination schedule. Information on viral load, immunological category, weight, height, and response to antiretroviral treatment from diagnosis to the last assessment was obtained. RESULTS: 19 patients were included, with a mean age of 12.6 years (SD ± 2.29). 58% were male. 80% of the patients presented protective immunoglobulin G antibodies against HAV 7-year post-vaccination. The antibody concentration was found to be between 13 and 80 mIU/mL (median of 80 mIU/mL). 52% showed some degree of immunosuppression. There was no statistically significant relationship between the presence of seroprotection and viral load, treatment failure, immunological category, and malnutrition. Twelve patients presented with antiretroviral treatment failure, and in 33% of them, the antibodies did not offer satisfactory seroprotection. CONCLUSION: 7-year post-vaccination, 80% of HIV-infected children maintain seroprotection titers against HAV.

INTRODUCCIÓN: Los niños infectados por el virus de la inmunodeficiencia humana (VIH) tienen mayor riesgo de presentar infecciones, incluyendo hepatitis por virus A (VHA). La vacuna inactivada contra el VHA es inmunógena en el huésped inmunocompetente. No hay estudios suficientes sobre el tiempo de seroprotección en niños infectados por el VIH. MÉTODO: Estudio de cohorte, analítico. Se incluyeron niños con infección por VIH-1 que recibieron la vacuna inactivada contra el VHA (dos dosis). Se les tomaron muestras sanguíneas para medición de anticuerpos, una 28 días después de la segunda dosis y otra 7 años después del esquema de vacunación. Se obtuvo información de carga viral, categoría inmunológica, peso y talla, y respuesta al tratamiento antirretroviral desde el diagnóstico hasta la última valoración. RESULTADOS: Se incluyeron 19 pacientes con una edad media de 12.6 años (± 2.29). El 58% fueron del sexo masculino. El 80% de los pacientes presentaron anticuerpos immunoglobulin G (IgG) contra el VHA protectores a los 7 años de la vacunación. La concentración de anticuerpos se encontró entre 13 y 80 mUI/ml (mediana: 80 mUI/ml). El 52% mostraron algún grado de inmunosupresión. No existe relación estadísticamente significativa entre la presencia de seroprotección y la carga viral, la falla al tratamiento, la categoría inmunológica ni la desnutrición. Doce pacientes presentaron falla al tratamiento antirretroviral; en el 33% de ellos los anticuerpos no ofrecían seroprotección satisfactoria. CONCLUSIONES: A 7 años posvacunación, el 80% de los niños con VIH mantienen títulos de seroprotección frente al VHA.

Cost-effective analysis of hepatitis A vaccination in Kerala state, India.

Several hepatitis A outbreaks have recently been reported in Kerala state, India. To inform coverage decision of hepatitis A vaccine in Kerala, this study aimed to examine the cost-effectiveness of 1) hepatitis A vaccination among children aged 1 year and individuals aged 15 years, and 2) serological screening of individuals aged 15 years and vaccination of susceptible as compared to no vaccination or vaccination without serological screening. Both live attenuated hepatitis A vaccine and inactivated hepatitis A vaccine were considered in the analysis. A combination of decision tree and Markov models with a cycle length of one year was employed to estimate costs and benefits of different vaccination strategies. Analysis were based on both societal and payer perspectives. The lifetime costs and outcomes were discounted by 3%. Our findings indicated that all strategies were cost-saving for both societal and payer perspectives. Moreover, budget impact analysis revealed that vaccination without screening among individuals aged 15 years could save the government's budget by reducing treatment cost of hepatitis A. Our cost-effectiveness evidence supports the inclusion of hepatitis A vaccination into the vaccination program for children aged 1 year and individuals aged 15 years in Kerala state, India.

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

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.

The Association between Message Framing and Intention to Vaccinate Predictive of Hepatitis A Vaccine Uptake.

As ongoing, sporadic outbreaks of hepatitis A virus (HAV) infections present public health challenges, it is critical to understand public perceptions about HAV, especially regarding vaccination. This study examines whether message framing changes the intention to vaccinate against HAV and self-reported vaccine behavior. Using a randomized controlled trial (N = 472) in February 2019 via Amazon Mechanical Turk, participants were randomized to one of four HAV vaccination message groups or a no-message control group. The message groups varied in their emphasis on the nature of outcomes (gain versus loss) and for whom (individual versus collective). The message frames were compared by intention to vaccinate, differences in message characteristics, and behavioral determinants. There was no difference in intention to vaccinate between gain- versus loss-framed messages (MD = 0.1, 95% CI = -0.1, 0.3) and individual- versus collective-framed messages (MD = 0.1, 95% CI = -0.1, 0.3). The intention to vaccinate against HAV in the no-message control group was very similar to that in the message groups. However, gain-framed messages were rated more positively in valence than loss-framed messages (MD = -0.5, 95% CI = -0.7, -0.3), which may be helpful for cultivating a positive public perception of HAV vaccination. The study also highlights the importance of comparing message frames to a no-message control in designing health communication messaging promoting HAV vaccination.

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

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

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.

Calendario de inmunizaciones infantil 2024 / childhood immunisation schedule 2024

Calendario de inmunización para población infantil.

Immunogenicity and safety of HavisureTM vaccine developed by Human Biologicals Institute in healthy subjects of 12 months to 49 years of age: A phase II/III, randomized, single blind, non-inferiority study.

BACKGROUND: Hepatitis A is an inflammation of the liver caused by the hepatitis A virus (HAV). It is transmitted mainly because of poor personal hygiene via the faecal/oral route through ingestion of contaminated food or water or through the direct contact with an infectious person. Though most of the infected individuals recover from the infection, a few may develop fatal fulminant hepatitis. In this randomized, multicenter study, immunogenicity and safety of Havisure™ vaccine of Human Biologicals Institute was compared with Havrix® vaccine. METHODS: The study was carried out in 528 eligible healthy subjects, in two age groups across eight centres in India. Group A included subjects of 19-49 years and Group B subjects of 12 months to below 19 years of age. All subjects received two doses of either Havisure™ vaccine or Havrix® vaccine as per randomization at six months interval. Blood samples for antibody titre estimation were collected before vaccination and 4-6 weeks after 2nd dose of vaccination. Immunogenicity was assessed by estimating seroconversion rate, seroprotection rate, and geometric mean titres of antibodies. Safety was evaluated by collection and analysis of data on solicited and unsolicited adverse events. RESULTS: Of 528 enrolled subjects, 493 subjects completed the study. There was 100% seroconversion and seroprotection in both the vaccine arms. There was no statistical difference in the geometric mean titres between the two vaccine arms. Pain and swelling at the site of injection were the most common local adverse events whereas fever and headache were the most common systemic adverse events observed in both vaccine arms. No serious adverse event was reported in the study. CONCLUSION: The study results indicate that the Havisure™ vaccine is immunogenic and safe when administered to healthy subjects of 12 months to 49 years of age, and is non-inferior to Havrix® Vaccine.

Impact of frequency and duration of freeze-dried inactivated tissue culture hepatitis A vaccine (Aimmugen®) vaccination on antibody titers; a japanese cross-sectional study.

BACKGROUND: The effect of the timing of additional doses and the long-term persistence of lyophilized inactivated tissue culture hepatitis A (HA) vaccine (Aimmugen®) on antibodies is unknown. METHODS: A single-center, cross-sectional, observational study was conducted in collaboration with the Japan Air Self-Defense Force, whose personnel were immunized with Aimmugen® when deployed to endemic areas. Patients who consented to this study after a medical examination with blood sampling between June 2022 and February 2023 were included; HA-IgG level in the residual serum was measured using the chemiluminescent immunoassay method. The exact vaccination history was investigated based on immunization records maintained by the Ministry of Defense, and a questionnaire was used to collect confounding factors. RESULTS: Of the 181 participants observed, 49 were in the unvaccinated group, and 132 were in the vaccinated group. Out of the vaccinated group, 6.8 % received either one or two doses, 40.9 % received three doses, and 52.3 % received more than four doses. IgG antibody titers (S/CO value) in each group (0, 1 or 2, 3, and over 4) increased in a frequency-dependent manner, with those vaccinated over four times showing significantly higher IgG antibody titers than all other groups (0.19 ± 0.10 vs 3.66 ± 3.00 vs 7.63 ± 3.57 vs 10.57 ± 1.86, respectively). When the number of months elapsed from the last vaccination to the date of blood collection in each group was plotted against IgG antibody titer, the slope of the regression line flattened out from a decreasing trend in the order 1 or 2, 3, over 4. CONCLUSIONS: Three doses of Aimmugen® are efficacious, but four or more doses induce more robust and sustained antibody production. Additionally, four or more doses may be effective when there is a need to ensure long-term immunity or risk of prolonged exposure.

Coadministered pneumococcal conjugate vaccine decreases immune response to hepatitis A vaccine: a randomized controlled trial.

OBJECTIVES: We explored the influence of coadministration on safety and immunogenicity of the most common travellers' vaccine hepatitis A (HepA) and the pneumococcal conjugate vaccine (PCV) increasingly used both at home and before travel. METHODS: Volunteers aged ≥18 years (n = 305) were randomly assigned 1:1:1 into three groups receiving: 13-valent PCV (PCV13) + HepA, PCV13, or HepA. Anti-pneumococcal IgG concentrations, opsonophagocytic activity (OPA) titres, and total hepatitis A antibody (anti-HAV) concentrations were measured before and 28 ± 3 days after vaccination. Adverse events (AEs) were recorded over 4 weeks. RESULTS: After vaccination, the anti-HAV geometric mean concentration was significantly lower in the PCV13+HepA than the HepA group: 34.47 mIU/mL (95% CI: 26.42-44.97 mIU/mL) versus 72.94 mIU/mL (95% CI: 55.01-96.72 mIU/mL), p < 0.001. Anti-HAV ≥10 mIU/mL considered protective was reached by 71 of 85 (83.5%) in the PCV13+HepA group versus 76 of 79 (96.2%) in the HepA group, p 0.008. The increases in anti-pneumococcal IgG and OPA levels were comparable in the PCV13+HepA and PCV13 groups, apart from a bigger rise in the PCV13+HepA group for serotype 3 (one-way ANOVA: serotype 3 IgG p 0.010, OPA p 0.002). AEs proved more frequent among those receiving PCV13 than HepA, but simultaneous administration did not increase the rates: ≥one AE was reported by 45 of 56 (80.4%) PCV13, 43 of 54 (79.6%) PCV13+HepA, and 25 of 53 (47.2%) HepA recipients providing structured AE data. DISCUSSION: Coadministration of HepA and PCV13 did not cause safety concerns, nor did it impact the patients' response to PCV13, apart from serotype 3. However, coadministered PCV13 significantly impaired antibody responses to HepA.

Durability of serologic responses to inactivated hepatitis A virus vaccination among people living with HIV following acute hepatitis A outbreak: a 5-year follow-up study.

Serologic responses to hepatitis A virus (HAV) vaccination may wane among immunocompromised populations. To evaluate the long-term seroresponses to 2-dose HAV vaccination, we retrospectively included people living with HIV (PLWH) who had achieved seroconversion within 12 months after vaccination at a university hospital during an outbreak of acute hepatitis A between 2015 and 2017. PLWH included in the study received either Havrix or Vaqta. The seroresponses were evaluated 60 months after the second dose of vaccination and estimated by the intention-to-treat (ITT) with last-observation-carried-forward (LOCF) and per-protocol (PP) analyses. Overall, 986 PLWH (median age, 34 years and CD4 count, 587 cells/µL) were included. The rates of PLWH with persistent seroprotection at month 60 of vaccination were 90.7% (894/986) and 97.4% (748/768) in the ITT with LOCF and PP analyses, respectively. PLWH with persistent seroprotection had achieved higher peak anti-HAV IgG titers after vaccination and had a slower decline in antibody levels compared with those with seroreversion. In the multivariable analysis, seroreversion at month 60 was associated with a higher body-mass index (per 1-kg/m2 increase, AOR, 1.10; 95% CI, 1.04-1.17), lowest-ever CD4 count (per 10-cell/µL increase, AOR 0.98; 95% CI, 0.97-1.00), plasma HIV RNA <200 copies/ml at vaccination (AOR, 0.28; 95% CI, 0.14-0.59), and having received Vaqta as the first dose of HAV vaccination (AOR, 0.44; 95% CI, 0.27-0.70). The seroprotection against HAV remained high in the long-term follow-up among PLWH on antiretroviral therapy after 2-dose HAV vaccination. Regular monitoring of seroresponses and timely administration of HAV vaccines are warranted to maintain seroprotection.

Immunogenicity persistence of hepatitis A vaccines Healive® and Havrix® among children:15 years follow-up and long-term prediction.

Healive® was the only Chinese WHO-prequalified inactivated vaccine for the hepatitis A virus, which has been widely used in national immunization programs in China. Long-term follow-up studies are needed to estimate the persistence of vaccine-induced antibody levels and the necessity for booster vaccines. During the trial, geometric mean concentrations (GMCs) and seroconversion rates (SRs) of anti-HAV antibodies were compared based on two different inactivated hepatitis A vaccines, Healive® and Havrix®. Four hundred children were randomly assigned to receive two doses of Healive® or Havrix® at 0 and 6 months. The current study assessed antibody persistence for both vaccines 15 years post-immunization. A mixed linear model was used to predict long-term antibody persistence. The GMCs were significantly higher for Healive® compared to Havrix® at 1, 6, 7, 66, 138 months (P < .001) and 186 months (P = .004 < .05) post-vaccination. Healive® and Havrix® reached a GMC of 164.8 mIU/ml and 105.7 mIU/ml post-15 years of vaccination, respectively. The seroconversion rates of both vaccines showed no statistically significant differences (97.9% for Healive® and 94.7% for Havrix®, P = .20). The prediction showed that Healive® would provide protection for a minimum of 30 years following immunization, with a lower limit of the 95% confidence intervals for GMCs greater than 20mIU/mL. Compared to Havrix®, the vaccine Healive® showed a stronger protective effect and better persistence among children at 15 years post-full immunization. Prediction indicated at least 30 years of antibody persistence for Healive® and at least 25 years for Havrix®.

Delaying the third dose of Japanese aluminum-free hepatitis A vaccine Aimmugen elicits effective immune responses against hepatitis A in adults.

Inactivated aluminum-adsorbed hepatitis A vaccines such as Havrix, Vaqta, and Avaxim are commonly used worldwide. These vaccines are typically administered in a two-dose series (at 0 and 6-12 months). However, a lyophilized inactivated aluminum-free hepatitis A vaccine, Aimmugen, which is approved in Japan, is typically administered in a three-dose series (at 0, 2-4, and 24 weeks). Hence, individuals visiting endemic hepatitis A areas receive the primary two doses of Aimmugen before traveling and the third booster dose much later. It is currently uncertain whether boosting with a delayed third dose of Aimmugen is effective, or whether a new vaccination schedule should instead be initiated. Therefore, we investigated the anti-hepatitis-A viral immune response of adult travelers who received the third dose of Aimmugen more than 24 weeks after the first dose. Participants were vaccinated with the third dose of Aimmugen more than 2 years after the first two doses. Antibody titers were measured at Day 0 (prevaccination) and at 28-42 days after the third dose of Aimmugen. Twenty-nine adult participants were enrolled in the study (14 men and 15 women; mean age ± standard deviation age, 36.2 ± 8.1 years). The interval between the first two doses and the third dose was 3-14 years. The seroprotection rate (i.e., the percentage of participants with anti-hepatitis A virus antibody titers ≥ 10 mIU/mL) was 96.6 % (28/29) at Day 0 and increased to 100 % (29/29) at Days 28-42. Geometric mean concentration increased from 105 to 4,013 mIU/mL. We demonstrated that delaying the third dose of Aimmugen still elicited effective immune responses after priming with two doses of the vaccine. Trial registration: UMIN Clinical Trials Registry (UMIN-CTR): MIN000013624. Registered 03 April 2014. https://center6.umin.ac.jp/cgi-bin/ctr/ctr_view_reg.cgi?recptno=R000015906.

A Randomized Clinical Trial of 1-Dose vs Accelerated 2-Dose Schedule for Hepatitis A Virus (HAV) Revaccination Among People With Human Immunodeficiency Virus Who Were Nonresponders or Had Seroreversion After Primary HAV Vaccination.

BACKGROUND: For people with human immunodeficiency virus (PWH) who have no serological responses to their primary hepatitis A virus (HAV) vaccination or have seroreversion after successful primary vaccination, the optimal revaccination strategy remains unclear. METHODS: In this open-label, randomized clinical trial, PWH who tested negative for anti-HAV antibodies after receiving a standard 2-dose series of primary HAV vaccination were enrolled and assigned in a 1:1 ratio to receive either 1 dose (the 1-dose group) or 2 doses of HAV vaccine administered 4 weeks apart (the 2-dose group). Serological response rates and anti-HAV antibody titers were compared at weeks 24 and 48. RESULTS: Of the 153 participants (77 in the 1-dose group and 76 in the 2-dose group), the overall serological response rates at week 48 after revaccination were similar between the 2 groups (2- vs 1-dose, 80.2% vs 71.4%, P = .20). However, anti-HAV antibody titers were consistently higher in the 2-dose group than in the 1-dose group. In subgroup analysis, PWH who were nonresponders to primary HAV vaccination were significantly more likely to mount a serological response after 2-dose HAV revaccination (68.4% vs 44.1%, P = .038). No severe adverse events were reported throughout the study. CONCLUSIONS: Two-dose HAV revaccination administered 4 weeks apart yielded similar serological responses as 1-dose revaccination among PWH who were nonresponders or had seroreversion after primary HAV vaccination. The 2-dose revaccination schedule generated significantly higher anti-HAV antibody titers and was more likely to elicit serological responses at week 48 among PWH who were nonresponders to primary HAV vaccination. Clinical Trials Registration. NCT03855176.

Safety of concomitant administration of inactivated hepatitis A vaccine with other vaccines in children under 16 years old in post-marketing surveillance.

BACKGROUND: Concomitant administration refers to the receipt of two or more vaccines during a single healthcare encounter, which is an efficient way to increase vaccination coverage in children. However, the post-marketing safety studies of concomitant administration are scarce. Inactivated hepatitis A vaccine (Healive®) has been used widely in China and other countries for more than a decade. We aimed to explore the safety of Healive® co-administered with other vaccines compared to Healive® alone in children under 16 years old. METHODS: We retrieved Adverse Events Following Immunization (AEFI) cases and vaccination doses of Healive® during 2020-2021 in Shanghai, China. The AEFI cases were divided into concomitant administration group and Healive® alone group. We used administrative data on vaccine doses as denominators to calculate and compare crude reporting rates between groups. We also compared baseline gender and age distribution, clinical diagnoses, and time interval from vaccination to onset of symptoms between groups. RESULTS: A total 319,247 doses of inactivated hepatitis A vaccine (Healive®) were used and 1,020 AEFI cases (319.50 per million doses) associated with Healive® were reported during 2020-2021 in Shanghai. There were 259,346 doses concomitantly administered with other vaccines and 830 AEFI cases (320.04 per million doses) were reported. There were 59,901 doses of Healive® that vaccinated alone, with 190 AEFI cases (317.19 per million doses). There was only one case with serious AEFI in concomitant administration group, with a rate of 0.39 per million doses. Reported rates of AEFI cases were similar between groups in general (p > 0.05). CONCLUSION: Concomitant administration of inactivated hepatitis A vaccine (Healive®) with other vaccines has a similar safe profile as Healive® alone.

Cost-effectiveness of expanded hepatitis A vaccination among adults with diagnosed HIV, United States.

Hepatitis A virus can cause severe and prolonged illness in persons with HIV (PWH). In July 2020, the Advisory Committee on Immunization Practices (ACIP) expanded its recommendation for hepatitis A vaccination to include all PWH aged ≥1 year. We used a decision analytic model to estimate the value of vaccinating a cohort of adult PWH aged ≥20 years with diagnosed HIV in the United States using a limited societal perspective. The model compared 3 scenarios over an analytic horizon of 1 year: no vaccination, current vaccine coverage, and full vaccination. We incorporated the direct medical costs and nonmedical costs (i.e., public health costs and productivity loss). We estimated the total number of infections averted, cost to vaccinate, and incremental cost per case averted. Full implementation of the ACIP recommendation resulted in 775 to 812 fewer adult cases of hepatitis A in 1 year compared with the observed vaccination coverage. The incremental cost-effectiveness ratio for the full vaccination scenario was $48,000 for the 2-dose single-antigen hepatitis A vaccine and $130,000 for the 3-dose combination hepatitis A and hepatitis B vaccine per case averted, compared with the observed vaccination scenario. Depending on type of vaccine, full hepatitis A vaccination of PWH could lead to ≥80% reduction in the number of cases and $48,000 to $130,000 in additional cost per case averted. Data on hepatitis A health outcomes and costs specific to PWH are needed to better understand the longer-term costs and benefits of the 2020 ACIP recommendation.