August 20, 2021
Hepatitis B virus (HBV) remains endemic throughout sub-Saharan Africa despite the widespread availability of effective childhood vaccines. In the Democratic Republic of the Congo, HBV treatment and birth-dose vaccination programs are not established.
In a new study published by Lancet Global Health, UNC researchers — including co-second author Camille Morgan, a dual Doctor of Medicine and Doctor of Philosophy student in the School of Medicine and the Gillings School of Global Public Health’s Department of Epidemiology — evaluated the feasibility and acceptability of HBV testing and treatment of pregnant women, as well as birth-dose vaccination of HBV-exposed infants.
The program was added to existing public health infrastructure to prevent mother-to-child transmission of HIV in the Democratic Republic of the Congo. This novel approach was funded, in part, by a two-year Gillings Innovation Lab award.
At two high-volume maternity centers in the city of Kinshasa, the research team screened pregnant women for HBV infection during routine prenatal care registration. Those who tested positive and had a gestational age of 24 weeks or less were included in this study, which ran between September 2018 and February 2019.
Of the 4016 women screened, 109 were positive for HBV and 90 participated in the study. Of the 88 infants born to mothers with HBV, 60 received the birth-dose vaccine and 46 received a vaccine during the 24-hour time frame defined as “timely vaccination” by the World Health Organization (WHO).
The researchers found no evidence of mother-to-child HBV transmission or serious vaccine-related side effects. In the mothers, the researchers observed no serious adverse side effects from the treatment (tenofovir disoproxil fumarate), aside from one woman who reported dizziness.
“We’re confident that birth-dose vaccination against HBV infection, integrated within the current expanded program of immunization and disease treatment, could accelerate progress toward HBV elimination in Africa,” said first author Peyton Thompson, MD, an assistant professor of infectious diseases in the UNC Department of Pediatrics.
In countries where a birth-dose of HBV vaccine has been introduced, studies have shown its effectiveness in preventing mother-to-child transmission. But transmission can still occur in some infants born to women with high viral loads if the birth-dose vaccine is not coupled with maternal antiviral prophylaxis.
In its 2020 guidelines on HBV prevention of mother-to-child transmission, the WHO recommended that HBV-infected women with high-risk HBV infections receive antiviral prophylaxis from the 28th week of pregnancy until delivery or beyond in order to prevent breakthrough mother-to-child transmission — this measure is in addition to infant vaccination, including a birth-dose vaccine. Until now, there was no published study evaluating this dual approach to preventing HBV mother-to-child transmission within the existing HIV framework in Africa.
“Our results support the feasibility of the WHO’s 2020 guidelines even in the most resource-challenged settings, especially when integrated into existing HIV prevention of mother-to-child transmission program infrastructure,” said Jonathan Parr, MD, assistant professor of infectious diseases in the UNC Department of Medicine.
The National Institutes of Health and the UNC Gillings School of Global Public Health funded this work through grants, including a Gillings Innovation Laboratory award.
Contact the UNC Gillings School of Global Public Health communications team at firstname.lastname@example.org.