Background to STOP HBV

Hepatitis B is the leading cause of liver disease in Africa. It causes liver cirrhosis and liver cancer, and 64 million people in Africa have hepatitis B.

Over two-thirds of all new infections globally happen in Africa. This is because of difficulties in implementing the tools to prevent new infections. The tools include rapid tests which can diagnose hepatitis B with a fingerprick test in 15 minutes, tests to measure the virus load, antiviral treatment which should be given to pregnant women with hepatitis B who have a high viral load, it can lower the virus load and reduce the risk of vertical transmission (mother to child transmission) and vaccines, which if started at birth can be highly effective to stop transmission.

What is the problem?

There are many healthcare centres in Africa where it is not possible to access hepatitis B viral load testing due to barriers to access equipment or test kits, or due to costs.

Recognising this issue, in the 2024 guidelines the World Health Organisation recommended to offer antiviral treatment with tenofovir to all HBsAg positive women regardless of viral load, if there were difficulties to access HBV DNA (virus load) testing.

But the guideline recognised that there was limited evidence of the effectiveness of this policy, and called for research to assess its effectiveness, safety and feasibility.

Why don’t we just give vaccination?

There are two problems. First, even when vaccination is given and started at the time of birth, it cannot prevent vertical transmission for women with a very high viral load, who are still at risk of transmission. Around 30% will still transmit with a very high viral load (>200,000 IU/ml) despite a birth dose vaccine.

Second, coverage of the critical birth dose vaccine is consistently low across Africa at only 18%. This gap in vaccine coverage has been difficult to cover, given that many births in Africa happen at home and not in a healthcare facility. There have been many issues identified in siloes between vaccine programmes and maternity services, misinformation about vaccines, issues with cold chain storage and distribution and financing.

How will STOP HBV help?

STOP HBV will assess whether giving tenofovir to all HBsAg pregnant women in two countries in Africa will prevent vertical transmission, in a setting of suboptimal birth dose vaccine coverage, and where access to HBV DNA testing is limited.

We will gather evidence on the safety after stopping tenofovir treatment, and explore health systems issues that could impact on the successful delivery of the programme. We will also conduct extensive patient and community engagement in both countries before and during the project. Finally we will conduct health economics modelling to determine the cost-effectiveness of this policy.

Together we will provide evidence to policy makers on key elements of this policy to prevent vertical transmission of hepatitis B in Africa.