Vaccine could reduce mother-to-child transmission
Elimination of the disease caused by the hepatitis B virus (HBV) is possible through the use of vaccination.
The hepatitis B vaccine was, in fact, the first vaccine able to prevent cancer – by inducing immunity to infection, it also prevents the development of chronic infection and its long-term sequelae or after-effects, such as cirrhosis and liver cancer. Receiving the hepatitis B vaccine at birth can prevent the transmission of HBV from an infected mother to her baby; yet in South Africa and many other sub-Saharan countries, the vaccine is only administered at six weeks of age, leaving the infant vulnerable to infection at the time of birth.
More than 2,5m South Africans are estimated to have chronic HBV infection; and are therefore at a great risk of liver cancer. According to the recent Globocan report, the disease is considered the third most common cause of cancer death, globally.
A study conducted by researchers at the Faculty of Medicine and Health Sciences (FMHS) of Stellenbosch University (SU) has just shown that infection with both HBV and HIV accelerates the development of liver cancer. The majority of patients presenting with liver cancer are young black males.
Due to mostly late presentation to health facilities, survival of these patients is very poor; with over 50% not surviving beyond one year after diagnosis, earning chronic hepatitis the nickname “silent killer”. The only way the situation can be averted is if chronic HBV infection is diagnosed in time and prompt therapy is given where appropriate.
The Viral Hepatitis Research Group is working with Life Assay Diagnostics, which is a biotechnology company, to develop a feasible point-of-care test for the dual detection of viral hepatitis B and HBV infectivity.
“The increasing availability of drugs for the treatment of HBV infection has exposed the lack of cost-effective methods for diagnosis and monitoring in resource-poor settings,” says Dr Monique Andersson, head of the Viral Hepatitis Research Group at the FMHS’s Division of Medical Virology.
In 2014 Andersson showed that pregnant women with hepatitis B alone may have high HBV viral loads and could therefore, without any intervention, be at high risk of transmitting infection to their infants.
“Routine screening for hepatitis B during pregnancy is still inexistent in most parts of sub-Saharan Africa. Highly infectious pregnant women remain unidentified; hence nothing can be done to lower their risk of transmitting the infection to their babies”, says Andersson.
The research group advocates for the first dose of the vaccine to be brought closer to the time of birth to reduce the risk of perinatal infection and for the implementation of routine screening for HBV infection during pregnancy and when HIV is diagnosed. In addition, they recommend that more resources should be invested into establishing proper care of patients infected with HBV alone, as these are currently a neglected group in terms of access to treatment.
This research group confirmed in 2010 that in the Western Cape HBV is being transmitted from mothers co-infected with both HBV and HIV to their new-born babies. “Our first study showed that HBV/HIV co-infected pregnant women have high HBV viral loads and are at risk for vertical transmission to their new-born infants, despite the availability of a safe, cheap and effective vaccine,” says Andersson.
