Progress Toward Elimination of Mother-to-Child Transmission of Hepatitis B Virus — Region of the Americas, 2012–2022

Discussion

Substantial progress has been made toward the elimination of MTCT of HBV infection in AMR. PAHO has supported vaccination against hepatitis B in the region since the 1990s by 1) advocating for vaccination to stakeholders, 2) providing technical support for the development of national vaccination policies, 3) building health care worker capacity, and 4) facilitating vaccine procurement.^§§ Mathematical models estimate the prevalence of chronic HBV infection among children aged ≤5 years, as measured by HBsAg seroprevalence, to be <0.1% regionally, and 14 countries met both regional and global impact targets for the elimination of MTCT of HBV infection (5,6). Among the 14 countries identified as likely to have met the HBsAg seroprevalence target, two reported HepB-BD and HepB3 coverage ≥95% during both 2021 and 2022, meeting both the regional and global programmatic targets for the elimination of MTCT of HBV infection, and both implemented antenatal and maternal and child health policies supporting the elimination of MTCT of HBV infection (5,6).

PAHO has endorsed a process for validating achievement of the elimination of MTCT of HBV infection (6), and regional and national validation committees have been established. Because countries are evaluated for the elimination of MTCT of HBV infection, representative seroprevalence data documenting the prevalence of chronic HBV infection in children are needed. Innovative approaches, such as the integration of HBsAg testing into other surveys or sampling focused on geographic areas with documented high risk for HBV infection such as the two-phase method for verifying the elimination of MTCT of HBV infection used in Colombia (7), might facilitate the collection of essential data.

Despite regional progress, an estimated 34,000 children aged ≤5 years in the Americas had chronic HBV infection in 2022 (8). Few countries are consistently achieving the ≥90% HepB3 global coverage target. Declines in HepB3 coverage during 2012–2022 threaten progress toward elimination of chronic HBV infection in children. These declines have been attributed to inadequate sustainable financing and reductions in social mobilization for vaccination, increasing vaccination hesitancy, insecurity linked to civil unrest, lack of easy access to health services for some populations, and recently, the COVID-19 pandemic and consequent health service disruptions^¶¶,***^{,†††,§§§,¶¶¶} (9,10). To overcome these constraints and improve HepB3 vaccination coverage, PAHO is working with countries to implement the recommendations in the 2021 Reinvigorating Immunization as a Public Good for Universal Health resolution**** and the new Regional Immunization Action Plan 2030.^††††

Although most children born in AMR live in countries with routine HepB-BD, 17 countries, particularly in the Caribbean and Latin Caribbean subregions (13 of the 17), have not introduced universal birth dose vaccination (3). In countries with HepB-BD, efforts to address disparities in coverage and access and to ensure timely administration will protect infants at risk for HBV infection (1). Most births in the region occur at health facilities; thus, implementation of policies such as standing orders for newborn HepB-BD vaccination before discharge of mother and child, paired with education of pregnant women and maternal and child health care staff members about the importance of the birth dose, can improve timely administration and coverage.

The region continues to expand efforts to achieve the elimination of MTCT of HBV infection by integrating antenatal viral testing, antiviral treatment during pregnancy when indicated, and provision of HBIG for HBV-exposed newborns into the established platforms providing interventions for the elimination of MTCT of HIV and syphilis (5). PAHO’s Strategic Fund is tasked with improving access to and reducing costs of hepatitis B–relevant health supplies and medicines for the region.^§§§§

Limitations

The findings in this report are subject to at least two limitations. First, current HepB-BD and HepB3 vaccination schedules and coverage or the elimination of MTCT programmatic indicators were not available for all countries or all years, limiting the completeness of summaries on regional progress on the elimination of MTCT of HBV infection. Second, not all countries have systems that differentiate reporting of timely versus any HepB-BD administration, thus potentially overestimating timely birth dose coverage.

Implications for Public Health Practice

Although progress has been made, declines in HepB3 coverage and the absence of HepB-BD introduction in 17 countries threaten PAHO’s progress toward the elimination of MTCT of HBV infection. To advance toward the regional goal of the elimination of MTCT of HBV infection, continued efforts are needed to support HepB-BD introduction and the achievement and maintenance of high HepB-BD and HepB3 coverage.