Hepatitis B virus (HBV) infection is the leading cause of cirrhosis and liver cancer in the world.in the most recent Morbidity and Mortality Weekly Report (MMWR) The World Health Organization (WHO) African Region (AFR) has made progress in eliminating mother-to-child transmission (MTCT) of HBV from 2016 to 2021, researchers report released by the U.S. Centers for Disease Control and Prevention (CDC).
Infant Hepatitis B Vaccination Campaign
In 2019, WHO AFR accounted for 66% of new HBV infections globally. This is despite the introduction of the HBV-birth dose (HepB-BD) in 2016, which improved outcomes with three doses of infant HepB3 in children five years or younger. The ultimate goal of the vaccine program is to reduce the incidence of MTCT by 30%, specifically by achieving hepatitis B surface antigen (HBsAg) seroprevalence of less than 2% and HepB3 coverage of more than 90% in children five years and younger by 2020. .
Because nearly two-thirds of mother-to-child transmitted chronic HBV infections occur in AFR, the World Health Organization recommends that all newborns receive HepB-BD within 24 hours of birth, followed by two to three additional doses of HepB during infancy.
About the study
In this study, researchers reviewed official HBV coverage data provided to WHO to obtain information on immunization activities in all 47 AFR countries to generate annual national vaccination coverage estimates. To this end, we conducted a MEDLINE literature review to identify HBsAg seroprevalence surveys against WHO AFR.
An HBsAg seroprevalence of less than or equal to 0.1% in children five years of age and younger reflects the elimination of mother-to-child transmission of HBV. Other population-based data were obtained from the Demographic Health Surveys (DHS) and the Population-based HIV Impact Assessment (PHIA) surveys.
Research result
By 2021, all 47 AFR countries offer three doses of HBV vaccine HepB3 to infants aged six weeks, while 14 countries also offer HepB-BD. As a result, 34% and 4% of countries achieved more than 90% HepB3 and more than 90% timely HepB-BD coverage, respectively.
Four countries have also achieved HBV control; however, none have been able to eliminate mother-to-child transmission, which occurs when HBsAg seroprevalence falls below 0.1% in children 5 years and younger.
HBsAg seroprevalence in pregnant women helps assess the risk of mother-to-child transmission of HBV. The data, from 11 of the 47 AFR countries, show HBsAg seroprevalence in Rwanda and Sierra Leone of 1.2% and 9.8% respectively.
The coronavirus disease 2019 (COVID-19) pandemic has disrupted immunization activities. As a result, fewer AFR countries are able to achieve HepB3 coverage of more than 90%, causing the value to drop from a peak of 20 between 2018 and 2021 to 16.
Therefore, HepB-BD was introduced in four AFR countries between 2016 and 2021 to improve HepB-BD coverage. However, regional HepB-BD coverage increased only from 10% to 17% in Nigeria and Senegal.
By 2021, nearly 33 million newborns in AFR countries have not received HepB-BD on time. These observations highlight the need for strategies to resume immunization activities in AFR countries to ensure that all eligible children who have missed HepB3 vaccination receive the recommended dose.
It is also critical to train health care workers to ensure that HepB-BD vaccination is integrated into neonatal care. These efforts will improve timely HepB-BD coverage in all 47 AFR countries. In addition to timely vaccination and improving vaccination coverage, determining whether pregnant women infected with hepatitis B virus are suitable for antiviral drug treatment can further reduce mother-to-child transmission of hepatitis B.
As of 2021, only 17 of the 47 AFR countries have national-level policies for newborn HBsAg testing and treatment. National-level serosurveys are also uncommon in these countries. In the future, HBsAg seroprevalence surveys can help monitor progress and inform policy decisions for HBV control and elimination of mother-to-child transmission of HBV in this WHO region.
in conclusion
Countries in the WHO African Regional Committee have not yet achieved the hepatitis B elimination targets set by the WHO African Regional Committee in 2016 and approved by the World Health Assembly.
To achieve these goals, the authors made several important recommendations, including the establishment of regional verification mechanisms to eliminate mother-to-child transmission of HBV and AFR disease control. AFR countries must also increase HepB-BD vaccination rates to ultimately prevent HBV-related morbidity and mortality.