Hepatitis B vaccines for children found effective in Bangladesh

The hepatitis B vaccine programme in Bangladesh was found highly effective in preventing chronic hepatitis B virus (HBV) infection among children, suggests a new icddr,b study in collaboration with the Institute of Epidemiology, Disease Control and Research (IEDCR), Bangladesh,  the U.S. Centers for Disease Control and Prevention, Atlanta (CDC) the World Health Organization (WHO) and the Stanford University, US.

The hepatitis B virus (HBV) infects the liver, and poses a serious threat to newborns whose mothers are already infected as this blood-borne disease can spread during birth, notes the recent WHO Global Hepatitis report

WHO recommends early hepatitis B vaccination within 24 hours of birth. Photo: Shumon Ahmed / icddr,b

The new findings published in the American Journal of Tropical Medicine and Hygiene indicate that the three-dose vaccine, as part of the current hepatitis B vaccination programme in Bangladesh, was highly effective in preventing chronic HBV infection among children, even though a birth dose was not given.

Children under age 6 years, if infected with the HBV, are the most likely group to develop chronic infections, which can lead to cirrhosis (scarring of the liver) or liver cancer. An estimated 257 million people are living with HBV infection worldwide.

Dr Eric E Mast, senior author of the study from the US CDC mentions, “The hepatitis B vaccine birth dose was, however, not included in the child vaccination schedule in Bangladesh because of the difficulties to administer a timely birth dose. In 2011, around 71 percent of births used to occur at home.” 

Most recent data according to Bangladesh Health and Demographic Surveillance (BDHS) 2016 suggests that health facility deliveries are increasing, with around 52 percent of deliveries still occurring at home.

The hepatitis B vaccine was introduced during 2003–2005 into the Expanded Program on Immunization (EPI) in Bangladesh, using the WHO-recommended schedule at 6, 10, and 14 weeks of age. WHO subsequently recommended early vaccination of babies against hepatitis B within 24 hours of birth.

Children <6 are the most vulnerable group to develp chronic liver infection. Photo: Shumon Ahmed / icddr,b

“Our study examined the presence of antibodies against HBV in over 2000 children across the country and found evidence of very low prevalence (0.05%) of chronic HBV infection in children who were born after the introduction of hepatitis B vaccine in Bangladesh,” observes Mr Repon Paul, first author of the study, former icddr,b researcher, and a public health doctoral student at University of New South Wales (UNSW).

On this World Hepatitis Day, the findings provide evidence that Bangladesh has achieved the Southeast Asia regional hepatitis B control target of ≤1% prevalence of chronic HBV infection among children aged 5 years by 2020.  The findings also add momentum to the WHO’s aim of eliminating hepatitis B by 2030.

The hepatitis B vaccination programme achieved 94.2 percent vaccination coverage, observed the researchers, adding that it is best to take the earliest opportunity to vaccinate after birth to prevent both mother-to-child and child-to-child transmission of HBV.

Unsafe sexual contact and medical practices can spread HBV. Photo: Shumon Ahmed / icddr,b

Hepatitis B is one of five types of viral hepatitis (A-E). HBV is transmitted through bodily fluids, especially blood. In addition to mother-to-child and child-to-child transmission, it is also transmitted through unsafe sexual contact and medical practices.

The study with icddr,b also found significantly higher HBV infection prevalence among children with a history of surgery than among children with no history of surgery - suggesting the need for safe medical practices.

Hepatitis B virus prevalence is highest in sub-Saharan Africa and east Asia, where between 5-10 percent of the adult population is chronically infected, according to the WHO global health sector strategy on viral hepatitis 2016-2021.

MN