Vaccination remains the most cost-effective strategy to get on track with hepatitis B elimination in resource-limited settingsPosted on by
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Midwife providing the 5-in-1 pentavalent vaccine (diphtheria-tetanus-pertussis [DTP], hepatitis B, and Haemophilus influenzae type b) during a routine vaccination session in Myanmar
In the 1990s, the Western Pacific Region had one of the highest prevalence rates of chronic hepatitis B infection in the world (>8%). As a result, in 2005, it was the first World Health Organization (WHO) Region to adopt a hepatitis B control goal through vaccination. With the financial support of GAVI (the Vaccine Alliance), countries in the region introduced hepatitis B vaccine into routine immunization, starting with a birth dose followed by 2-3 additional doses. CDC worked with WHO, Ministries of Health, and global partners to improve hepatitis B vaccination and verify the achievement of the regional hepatitis B control goal. In 2017, the Western Pacific Region was successful at decreasing the prevalence rate of chronic hepatitis B infection to less than 1% among school-aged children because of the successful implementation of hepatitis B vaccination.
The success achieved in the Western Pacific Region could be used as a lesson for other WHO Regions and countries that are experiencing a high burden of hepatitis B, most notably the African and South-East Asia Regions. Most of the countries in Africa (36 of 47) do not have a birth dose of hepatitis B vaccine in their immunization schedule despite WHO recommendation. In a recent supplement released by the Pan African Medical Journal on the future of immunization in Africa, three articles advocated for the need of hepatitis B vaccine birth dose in Africa to be able to achieve elimination. In the absence of the universal birth dose, the transmission of hepatitis B virus (HBV) infection from mother to child remains a major source of chronic liver disease when infected children become adults. Chronic HBV infection develops in 90% of infants infected before 1 year of age and contributes to over half of infections. As evidenced by efforts in Uganda, vaccinating adults, even in high-prevalence countries, has not been shown to be cost-effective in the long term because babies will keep getting infected without a birth dose and 2-3 follow-up doses.
One of the concerns with introduction of hepatitis B birth dose in resource-limited settings is cost. In fact, in most low-income countries, the birth dose costs only $0.20, which makes it one of the cheapest vaccines available. In the Western Pacific Region, even after GAVI discontinued financial support for hepatitis B vaccine birth dose, countries identified other funding opportunities because hepatitis B is a priority disease. Therefore, political commitment is needed to support introduction of hepatitis B vaccine birth dose in high-prevalence countries. One example is Myanmar, which had to discontinue hepatitis B vaccine birth dose after GAVI stopped financing. However, in 2016, Myanmar reintroduced the birth dose in health facilities using government funds because it realized the importance of addressing the high burden of hepatitis B infection in the country. Countries in Africa could also advocate for birth dose introduction given the high burden.
Another concern is the challenge of vaccinating children born at home or in health facilities that do not have refrigeration for vaccines. The birth dose of hepatitis B vaccine is most effective if administered within 24 hours after birth or, if not possible, within 7 days of birth at the latest. Vaccine manufacturers have not yet changed their vaccine vial labels to mention the possibility of storing the vaccine at room temperature for a specific duration (controlled temperature chain). However, evidence has shown that the hepatitis B vaccine birth dose can be stored up to one month outside refrigeration if the temperature is monitored and does not exceed 37°C. Pilot projects in several countriesshowed that the vaccine stored outside the cold chain was as effective as the vaccine stored in the refrigerator, and coverage with the hepatitis B vaccine birth dose increased significantly after implementing vaccination outside the cold chain. CDC supported several countries in successfully implementing use of hepatitis B vaccine birth dose outside the cold chain.
Provision of the hepatitis B vaccine birth dose relies on good coordination between the immunization program and the maternal and child health program. During my visit to Myanmar in October 2016, I was impressed by the fact that midwives are also responsible for routine vaccination. This is the perfect situation for birth dose delivery where the person who delivers the baby usually gives the vaccine. Since midwives in Myanmar were already trained in vaccination, they would not need extensive training to give the birth dose if they have access to the vaccine. In Myanmar, 64% of births occur outside hospitals but 71% of births are performed by skilled birth attendants (midwives). Therefore, using some of the strategies described above, such as using the vaccine outside the cold chain, would help reach more children with the birth dose and decrease the burden of disease in Myanmar.
A recent CDC analysis showed that hepatitis B vaccination is higher in countries that have high rates of births delivered in health facilities and high rates of skilled attendance at birth. In countries where skilled birth attendance is low, other strategies can be used. CDC supported several projects that showed the positive impact of educating community health workers, village volunteers, and pregnant women on the importance of hepatitis B vaccine birth dose. In regions where skilled personnel are lacking, administration of hepatitis B vaccine birth dose in a compact pre-filled auto-disable device (CPAD) outside the cold chain could be the solution if production is scaled up.
Personally and professionally, I am excited about contributing to the elimination of hepatitis B globally. Children everywhere deserve a healthy life free from chronic hepatitis B infection and liver cancer. At the moment, the most cost-effective approach in resource-limited settings is provision of the hepatitis B vaccine birth dose followed by 2-3 additional doses of pentavalent vaccine. Because 194 WHO Member States endorsed the adoption of the Global Health Sector Strategy on Viral Hepatitis in 2016, which calls for elimination by 2030, more efforts are needed to promote hepatitis B vaccine birth dose introduction and increase vaccination in Africa and Asia. CDC’s commitment to collaborating with global partners to eliminate hepatitis B will continue to contribute to the impact of hepatitis B vaccination, as shown in the Western Pacific Region.