Efficacy of Tenofovir Disoproxil on Mother-to-child Transmission of HBV in Tokombéré, Cameroon in Pregnant Women

Pregnant women with HBeAg-positive viral hepatitis b or high viral load will receive Tenofovir disoproxil fumarate (TDF) from the 28th week of amenorrhoea until 6 weeks after delivery. Their newborns will receive the hepatitis B vaccine, starting with one dose at birth and followed by three booster doses, according to the Expanded Programme on Immunisation. The investigators hypothesise that a short course of TDF could greatly reduce the risk of HBV MTCT in pregnant women at high risk of MTCT (HBeAg positive or with high viral load).

Inclusion criteria: * Pregnant women with a term of less than 24 weeks of amenorrhea; * HBsAg positive ; * HBeAg positive or HBeAg negative with a high viral load ( \> 200 000 UI/ml) ; * 16 years old or more on the inclusion day ; * Signature of free and informed consent (for pregnant women aged 16 to 21, the participant's consent as well as the authorization of a parent/adult husband/ legal tutor will be collected) which also includes consent for the children Exclusion criteria : * HIV co-infection; * Women treated for HBV; * Creatinine clearance \