Scaling up HBV birth dose vaccine coverage could help avert more than 500,000 deaths
Click Here to Manage Email Alerts
Key takeaways:
- By December 2021, 14 countries in the African Region provided the hepatitis B birth dose vaccine.
- Birth dose vaccine coverage increased from 10% in 2016 to 17% in 2021.
Bolstering the introduction of hepatitis B birth dose vaccines and verifying progress in eliminating mother-to-child transmission are among strategies critical to achieving hepatitis B virus control in Africa, WHO and CDC researchers wrote.
“Most chronic HBV infections are acquired through mother-to-child transmission or during early childhood, and approximately two-thirds of these infections occur in [the WHO African Region],” Hyacinte J. Kabore, DDS, of the Vaccine-Preventable Disease Unit at the WHO regional office for Africa, and colleagues wrote in Morbidity and Mortality Weekly Report. “In 2016, the WHO African Regional Committee endorsed two targets for hepatitis B control.”
The first was a 30% reduction in incidence — equating to hepatitis B surface antigen prevalence of no more than 2% in children aged 5 years and older — and the second, at least 90% coverage by 2020 in providing three infant doses of hepatitis B vaccine (HepB3). “In 2021, [African Region] countries endorsed a call to develop strategies for elimination of mother-to-child transmission of HBV, including increasing hepatitis B birth dose and HepB3 coverage and improving access to antenatal care and quality delivery services,” the authors continued.
To measure progress toward HBV control and elimination of mother-to-child transmission in the African Region (AFR), Kabore and colleagues analyzed country immunization activities reported to WHO and UNICEF.
Immunization activity
By 2014, all 47 countries in AFR had introduced HepB3 infant vaccination and, by December 2021, 14 countries provided hepatitis B birth dose (HepB-BD). Eight were in the West subregion.
Regional HepB3 coverage ranged from 75% in 2019 to 71% in 2021. Eighteen countries reached HepB3 coverage of at least 90% by 2016, which peaked at 20 countries in 2018 and then declined to 16 in 2021. The authors attributed the “disruption in immunization services” to the COVID-19 pandemic.
Regional HepB-BD coverage increased from 10% in 2016 to 17% in 2021. Researchers noted Algeria and Cabo Verde reached coverage rates of 90% or greater, and Namibia and Senegal achieved 50% or greater coverage.
“Based on modeled estimates, maintaining current HepB3 coverage and increasing HepB-BD coverage to 90% or greater in all countries in the region could avert 554,318 HBV-related deaths among 2020-2030 birth cohorts,” Kabore and colleagues wrote.
Seroprevalence in children
HBsAg seroprevalence surveys conducted at national or regional levels in eight countries revealed seroprevalence of no more than 2% in children of various ages in Ethiopia, Mauritania, Rwanda, Sierra Leone, Uganda and Zambia. Seroprevalence among children aged 5 years or younger ranged from 0.7% to 4.5% in the Democratic Republic of Congo, Ethiopia, Mauritania, Nigeria and Sierra Leone.
No country in the AFR achieved an HBsAg seroprevalence of 0.1% or less.
Modeling studies estimated a seroprevalence of 2.5% (95% CI, 1.7-4) among children aged 5 years or younger in AFR, which accounts for approximately 69% of children infected with HBV worldwide.
Mother-to-child HBV transmission
By December 2021, only six countries had implemented the elimination of mother-to-child transmission guidelines, despite 21 countries developing a plan.
To recognize progress made toward achieving this goal, WHO created a certification program measured by bronze, silver and gold tiers. Based on hepatitis B immunization interventions in 2021, Botswana could be eligible for bronze tier status, while Namibia, Sao Tome and Principe, and Senegal may be eligible for silver. Algeria and Cabo Verde could achieve gold-tier certification.
“Establishing a regional verification mechanism for hepatitis B control and elimination of mother-to-child transmission of HBV could elevate the profile of elimination initiatives in AFR,” Kabore and colleagues concluded. “Scaling up the introduction of HepB-BD and strategies to increase timely HepB-BD and HepB3 coverage would accelerate the reduction of preventable hepatitis B-associated morbidity and mortality and progress toward 2030 hepatitis B elimination goals.”
Collapse
Read more about
Click Here to Manage Email Alerts