UNITAID published a report in August 2022 to examine the “landscape of tools and interventions” to prevent mother-to-child transmission of HIV, syphilis, hepatitis B, and Chagas. Mother-to-child transmission is also known as vertical transmission. The report identifies this as a target to “accelerate progress towards global elimination goals”. In this article we examine the role of vaccination in the report, and in the wider context of the WHO’s “Triple Elimination” agenda.
The “Triple Elimination” agenda “seeks to encourage countries to pursue an integrated and coordinated approach to eliminating vertical transmission of HIV, syphilis, hepatitis B, and in countries where it is endemic, Chagas”. UNITAID’s report explores the current challenges that we face in tackling vertical transmission and identifies “new, emerging, or underutilised products and interventions”.
As part of the WHO’s three 5-year interlinked global strategies against HIV, syphilis, and hepatitis B, several ambitions were set out:
- Zero new HIV infections among children by 2020;
- A 30% reduction in new cases of chronic HBV infection by 2020;
- <50 cases of congenital syphilis per 100,000 live births in 80% of countries.
The report states that “none” of these targets was achieved. Thus, an “updated and unified” strategy was required. How, in this most recent publication, is vaccination factored into the global strategy?
The report states that the “cornerstone of hepatitis B prevention is vaccination”. As we discuss in our article for World Hepatitis Day 2022, there is currently an effective vaccine against hepatitis B. UNITAID suggests that the childhood HBV vaccine series is “highly effective at preventing acquisition of infection during childhood”. Although acknowledging “gaps”, the report highlights that there is an 85% global coverage of the “3-dose infant HBV immunisation series”.
“In sub-Saharan Africa, vaccination was found to be the most cost-effective intervention to reduce perinatal HBV infection rates.”
However, the report states that “childhood vaccination alone cannot achieve elimination goals” as perinatal transmission is a “growing proportion” of new infections. As other strategies are considered, the report also emphasises the need to accelerate advances in vaccine technology. Possibilities include “prefilled auto disposable devices to deliver accurate birth dosage and remove cold chain barriers”. This technology, UNITAID suggests, will be “more cost effective with minimum wastage”.
Despite WHO encouragement of re-labelling the hepatitis B vaccines “for use in a controlled temperature chain (CTC), no prequalified product” has been made available. However, there are updates to traditional technology that are worth highlighting. Uniject, a “1-dose pre-filled auto disabled disposable syringe” is one such update. This is simple to use and is recommended for “outreach settings”.
The report suggests that new technologies are needed, both on a diagnostic front and vaccine front. Innovations include “easier methods of vaccine delivery” and “less restrictive cold chain requirements for vaccine storage and delivery”. As we move ever closer to 2030’s target of elimination, innovation is needed more than ever.
For more information on vaccine technology for hepatitis and HIV come to the World Vaccine Congress in Europe 2022.