Africa Challenged by Hepatitis B Mother-to-Child Transmissions

Hepatitis B virus (HBV) control in the World Health Organization (WHO) African Region is gradually improving with the addition of full 3-dose vaccine regimen and birth-dose vaccine supplies to highly impacted areas, according to new research.

Data from the Centers for Disease Control and Prevention (CDC) suggest HBV management can be accelerated with greater vaccination efforts and interventions to eliminate mother-to-child transmissions in the Africa Region—an area currently constitutes two-thirds of all new chronic HBV infections.

Investigators led by Hyacinte J. Kabore, DDS, of the Vaccine-Preventable Disease Unit at the WHO Regional Office for Africa in the Republic of Congo, analyzed progressed made to achieve HBV control and elimination of mother-to-child transmissions in Africa from 2016 – 2021. The team noted that the WHO endorsed 2 targets for strategy to control HBV in the region in 2016:

• 30% reduction in disease incidence, per hepatitis B surface antigen (HBsAg) prevalence of ≤2% in children ≤5 years old
• ≥90% HBV 3-dose vaccine coverage by 2020

Five years later, African countries endorsed additional calls for HBV elimination through means including increased birth-dose vaccinations and 3-dose vaccine regimens, as well as improved access to antenatal care.

The team obtained country immunization activities in a review of annual national WHO and UNICEF vaccination coverage estimate data, while HBsAg seroprevalence was interpreted through a literature review of relevant research subjects.

All 47 African countries introduced 3-dose HBV infant vaccinations by 2014. Within 7 years, 14 (30%) countries provided birth-dose vaccine. Kabore and colleagues observed annual regional 3-dose HBV vaccine coverage ranging from 75% in 2019 to 71% in 2021. More than one-third (n = 18 [38%]) countries achieved ≥90% 3-dose vaccine coverage in 2016; the most in a recorded year was 20 (43%) in 2018. By 2021, the rate declined to 16 (34%) countries.

Regarding birth-dose vaccines, coverage increased from 10% in 2016 to 17% in 2021. In the observed time period, only Algeria and Cabo Verde achieved ≥90% birth-dose HBV vaccine dose coverage; Namibia and Senegal achieved ≥50% coverage.

Among the HBsAg seroprevalence surveys conducted in children from 8 (17%) countries, 7 reported seroprevalence of ≤2%. No country achieved ≤0.1% seroprevalence among children. Modeling assessments estimated a 2.5% seroprevalence among African region children aged ≤5 years old (95% CI, 1.7 – 4.0); that estimate would account for 69% of all infected children globally.

Nearly half (n = 21 [45%]) of African countries developed a mother-to-child transmission elimination plan for HIV, syphilis and HBV; however, only 6 countries reported implementing their guidelines for HBsAg testing of pregnant women, provision of antiviral medications to HBsAg-positive women, and administrating birth-dose HBV vaccinations to newborns. By end of 2021, ≥90% of pregnant women from 29 (62%) African countries had ≥1 antenatal care visit.

“In addition to providing timely (birth-dose HBV vaccination) and (3-dose HBV vaccination), the identification of pregnant women with HBV infection and provision of antiviral medications for those who are eligible for treatment would further advance eliminating mother-to-child transmission of HBV,” investigators wrote. “However, as of 2021, only 17 (36%) African countries had national policies for antenatal HBsAg testing and treatment, and nationally representative serosurveys in Africa were uncommon.”

The team concluded that establishing better regional verifications for HBV control and elimination of mother-to-child transmissions could “elevate the profile of elimination initiatives” in Africa.

“Scaling up the introduction (birth-dose HBV vaccination) and strategies to increase timely (birth-dose HBV vaccination) and (3-dose HBV vaccination) coverage would accelerate the reduction of preventable hepatitis B–associated morbidity and mortality and progress toward 2030 hepatitis B elimination goals,” they wrote.

References

1. ^{Kabore HJ, Li X, Alleman MM, et al. Progress Toward Hepatitis B Control and Elimination of Mother-to-Child Transmission of Hepatitis B Virus — World Health Organization African Region, 2016–2021. MMWR Morb Mortal Wkly Rep 2023;72:782–787. DOI: http://dx.doi.org/10.15585/mmwr.mm7229a2}
2. ^{World Health Organization. Global progress report on HIV, viral hepatitis, and sexually transmitted infections, 2021. Accountability for the global health sector strategies 2016–2021: actions for impact. Web annex 1: key data at a glance. Geneva, Switzerland: World Health Organization; 2021. http://apps.who.int/iris/bitstream/handle/10665/342808/9789240030985-eng.pdf}