Optimization of Mother-to-Child Hepatitis B Virus Prevention Program: Integration of Maternal Screening and Infant Post-vaccination Serologic Testing.

BACKGROUND: Evaluation of the impact on mother-to-child transmission (MTCT) of a HBV-prevention program that incorporates maternal antiviral prophylaxis is hindered by the limited availability of real-world data. METHODS: This study analyzed data on maternal HBV screening, neonatal immunization, and post-vaccination serologic testing (PVST) for HBsAg among at-risk infants born to HBV carrier mothers from the National Immunization Information System during 01/01/2008-31/12/2022. Through linkage with the National Health Insurance Database, information of maternal antiviral therapy was obtained. Multivariate logistic regression was performed to explore MTCT risk in relation to infant-mother characteristics and prevention strategies. RESULTS: Totally, 2,460,218 deliveries with maternal HBV status were screened. Between 2008 and 2022, the annual HBsAg and HBeAg seropositivity rates among native pregnant women aged 15-49 years decreased from 12.2% to 2.6% and from 2.7% to 0.4%, respectively (p for both trends < 0.0001). Among the 22,859 at-risk infants undergoing PVST, the MTCT rates differed between infants born to HBsAg-positive/HBeAg-negative and HBeAg-positive mothers (0.75% and 6.33%, respectively; p < 0.001). The MTCT rate was 1.72% (11/641) for infants born to HBeAg-positive mothers with antiviral prophylaxis. MTCT risk increased with maternal HBeAg-positivity (OR 9.29, 6.79-12.73) and decreased with maternal antiviral prophylaxis (OR 0.28, 0.16-0.49). For infants with maternal HBeAg-positivity, MTCT risk was associated with mothers born in the immunization era (OR 1.40, 1.17-1.67). CONCLUSIONS: MTCT was related to maternal HBeAg-positivity and effectively prevented by maternal prophylaxis in the immunized population. At-risk infants born to maternal vaccinated cohorts might possibly pose further risk.

Acute reactions after a homologous primary COVID-19 vaccination series: Analysis of Taiwan V-Watch data.

INTRODUCTION: The ChAdOx1 nCoV-19 (ChAd), mRNA-1273 (m1273), MVC-COV1901 (MVC), and BNT162b2 (BNT) COVID-19 vaccines received authorization for emergency use in Taiwan beginning in February 2021. We investigated acute reactions to homologous primary COVID-19 vaccination series in adults aged ≥ 18 years. METHODS: In this prospective observational study based on smartphone data (Taiwan V-Watch), we calculated the frequencies of self-reported local and systemic acute reactions within 7 days of a COVID-19 vaccination, and the health effects up to 3 weeks after each dose. Those who reported adverse reactions after both doses were assessed by the McNemar test. RESULTS: During 22 March 2021-13 December 2021, 77,468 adults were enrolled; 59.0 % were female and 77.8 % were aged 18-49 years. For both doses of all four vaccines, the local and systemic reactions were minor in severity and highest on days 1 and 2 after vaccination, and declined markedly until day 7. For 65,367 participants who provided data after the first and second doses, systemic reactions were more frequent after dose 2 of the BNT and m1273 vaccines (McNemar tests: both p < 0.001), while local reactions were more frequent after dose 2 of the m1273 and MVC vaccines (both p < 0.001), compared with dose 1 of the homologous vaccine. Among the participants aged 18-49 years, the percentage who missed work on the day after vaccination was slightly higher among women (9.3 %) than among men (7.0 %). CONCLUSIONS: Acute reactogenicity and impact of work absenteeism for the four COVID vaccines in the V-Watch survey were mild and of short duration.

Risk of myocarditis and pericarditis following coronavirus disease 2019 messenger RNA Vaccination-A nationwide study.

BACKGROUND: An extended interval between the two primary doses may reduce the risk of myocarditis/pericarditis after COVID-19 mRNA vaccination. Taiwan has implemented a two-dose regimen with a 12-week interval for adolescents. Here we present nationwide data of myocarditis/pericarditis following COVID-19 vaccinations. METHODS: Data on adverse events of myocarditis/pericarditis were from the Taiwan Vaccine Adverse Events Reporting System between March 22, 2021, and February 9, 2022. The reporting rates according to sex, age, and vaccine type were calculated. We investigated the rates among young individuals under different two-dose intervals and among those who received two doses of different vaccines. RESULTS: Among 204 cases who met the case definition of myocarditis/pericarditis, 75 cases occurred after the first dose and 129 after the second. The rate of myocarditis/pericarditis after COVID-19 vaccination varied across sex and age groups and was highest after the second dose in males aged 12-17 years (126.79 cases per million vaccinees) for the BNT162b2 vaccine and in males aged 18-24 years (93.84 cases per million vaccinees) for the mRNA-1273 vaccine. The data did not suggest an association between longer between-dose interval and lower rate of myocarditis/pericarditis among males and females aged 18-24 or 25-29 years who received two doses of the BNT162b2 or mRNA-1273 vaccine. Rates of myocarditis/pericarditis in males and females aged 18-49 years after receiving ChAdOx1-S - mRNA-1273 vaccination was significantly higher than after ChAdOx1-S - ChAdOx1-S vaccination. CONCLUSIONS: Myocarditis and pericarditis are rare following mRNA vaccination, with higher risk occurring in young males after the second dose.

COVID-19 Severity and Neonatal BCG Vaccination among Young Population in Taiwan.

BACKGROUND: Data have not been reported to explore the relation between COVID-19 severity and BCG vaccination status at the individual patient level. METHODS: Taiwan has a nationwide neonatal BCG vaccination program that was launched in 1965. The Taiwan Centers for Disease Control established a web-based National Immunization Information System (NISS) in 2003 and included all citizens' BCG vaccination records in NISS for those born after 1985. We identified COVID-19 Taiwanese patients born after 1985 between 21 January and 19 March 2021. Study participants were further classified into ages 4-24 years (birth year 1996-2016) and 25-33 years (birth year 1986-1995). We described their clinical syndrome defined by the World Health Organization and examined the relation between the COVID-19 severity and BCG vaccination status. RESULTS: In the 4-24 age group, among 138 BCG vaccinated individuals, 80.4% were asymptomatic or had mild disease, while 17.4% had moderate disease, 1.5% had severe disease, and 0.7% had acute respiratory distress syndrome but none of them died. In contrast, all 6 BCG unvaccinated individuals in this age group experienced mild illness. In the 25-33 age group, moderate disease occurred in 14.2% and severe disease occurred in 0.9% of the 106 patients without neonatal BCG vaccination records, as compared to 19.2% had moderate disease and none had severe or critical disease of the 78 patients with neonatal BCG vaccination records. CONCLUSIONS: Our finding indicated that BCG immunization might not relate to COVID-19 severity in the young population.

The Impact of Universal Infant Hepatitis B Immunization on Reducing the Hepatitis B Carrier Rate in Pregnant Women.

BACKGROUND: The hepatitis B virus (HBV) status of pregnant women affects HBV vaccine failure in their offspring. This study is aimed to investigate the impact of the universal infant HBV vaccination program on the long-term hepatitis B surface antigen (HBsAg) rate in pregnant women. METHODS: Using the National Immunization Information System, we examined a 32-year period of cross-sectional data on a maternal HBsAg and hepatitis B e antigen (HBeAg) screening program launched in July 1984. An age-period-cohort model analysis of 940 180 pregnant women screened for July 1996-June 1997 and the years 2001, 2006, 2011, and 2016 was applied. RESULTS: The annual HBsAg- and HBeAg-seropositive rates decreased from 13.4% and 6.4%, respectively, for the period 1984-1985 to 5.9% and 1.0% in 2016 (P for both trends < .0001). Pregnant women with birth years after July 1986 (the HBV vaccination cohort) had the lowest relative risk (0.27 [95% confidence interval, .26-.28]) of HBsAg positivity compared with birth years before June 1984. CONCLUSIONS: The birth cohort effect in relation to the universal infant HBV immunization program has effectively reduced the HBV carrier rate in pregnant women and the burden of perinatal HBV infection on the next generation.

Effect of age on the incidence of acute hepatitis B after 25 years of a universal newborn hepatitis B immunization program in Taiwan.

BACKGROUND: Raising concerns about the waning immunity of cohorts receiving hepatitis B virus (HBV) vaccination in infancy persuaded us to identify the changing incidence of acute hepatitis B (AHB) in children and young adults. METHODS: Data on AHB surveillance through the National Notifiable Disease Surveillance System from July 2001 to June 2009 were collected and described. Cases were divided into 2 cohorts according to their birth year: before or after the universal newborn HBV vaccination program. Age-specific incidence was compared for the 2 birth cohorts with diagnosis at age 15-24 years. RESULTS: In total, 2226 patients with AHB were identified. AHB rates varied by age; the highest rates occurred among unvaccinated individuals aged 25-39 years (2.33/100 000). Due to breakthrough HBV infection from mother-to-infant transmission, vaccinated infants (0.78/100 000) had higher rates than those aged 1-14 years (0.04/100 000), who had the lowest rates. The incidence in vaccinated birth cohorts was significantly lower than in unvaccinated birth cohorts among patients 15-24 years old, with an adjusted-relative risk of 0.42. CONCLUSIONS: Implementation of universal-at-birth HBV immunization programs has effectively reduced the occurrence of AHB among adolescents and young adults in Taiwan for >25 years, making infants and the 25-39-year-old cohort additional targets for preventing AHB.