Global childhood immunization coverage remains lower than pre-Covid levels, increasing the risk of disease outbreaks—including of highly infectious diseases like measles. In 2023, inadequate measles vaccine coverage drove outbreaks worldwide, resulting in over 10.3 million cases (according to WHO and U.S. CDC estimates), a 20% increase from 2022. Measles vaccines are affordable, can be delivered even in difficult places, and have saved more lives than any other vaccine in the last 50 years. However, persistent coverage gaps mean far too many children are still dying from the disease.
A simple switch
Consider a rural or semi-rural health facility: two children have shown up to receive a measles-containing vaccine dose. If unused, MCV doses need to be discarded six hours after the vial has been opened. If an HCW only vaccinates two children during that six-hour period, eight doses will be wasted. In this scenario, it’s not uncommon for HCWs to turn these two children away due to fears of wastage and stockouts.
Switching from 10-dose to 5-dose MCV vials is a straightforward, cost-effective way to reduce HCW hesitancy, which increases coverage and lowers the risk of measles outbreaks. The MCV 5-dose presentation is identical to the 10-dose presentation—the products have the same formulation, reconstitution, storage and handling, waste management, and WHO prequalification status.
A growing body of evidence
A landmark Zambia-based study provided compelling evidence for the 5-dose switch: districts using 5-dose vials had 47% lower wastage, 4.9% higher first-dose coverage, and 3.5% higher second-dose coverage compared to those using 10-dose vials. Since the study was published, additional countries have shared evidence linking 5-dose vials to greater frequency of measles vaccination sessions, improved timeliness of vaccination, boosted first- and second-dose MCV coverage, reduced wastage, and lowered vaccine procurement costs. Despite evidence supporting the switch, adoption of fewer-dose vials in Gavi countries remained low as of 2020.
Advocacy and country assistance
Since 2021, Linksbridge has led coordination, analytics, and advocacy efforts that have proved critical to countries’ adoption of the 5-dose MCV vial. By providing technical assistance to WHO and UNICEF regional offices and to country EPI teams across five of six WHO regions, we’ve helped turn expressions of interest into tangible action. Our Decision-Making Assessment Tool has aided EPI managers in assessing the programmatic and financial tradeoffs of making the switch. We’ve collaborated with partners to streamline the switch application process, and our team has worked to elevate country experiences during important convenings, including EPI managers’ meetings, technical and regional working group sessions, and webinars targeting National Immunization Technical Advisory Group leaders.
In addition to technical assistance, Linksbridge has established a centralized repository of evidence-based, user-friendly resources that clearly outline the justification for fewer-dose vials and the transition process. Various Linksbridge-developed materials are publicly available on TechNet, including an MCV 5-dose one-pager, a “How to Switch” resource for EPI managers navigating the transition and Gavi switch application form, and documentation of HCW experience with fewer-dose vials in India, the Asia Pacific region, and the WHO African region.
Life-saving transition
Since 2021, more than 350,000 additional measles-zero-dose children under age 1 are reached annually with MCV following country switches to fewer-dose vials, according to Linksbridge estimates. By the end of 2024, 33 Gavi-73 countries had transitioned to fewer-dose MCV vials. By 2027, 23 more countries are expected to switch—a change that could result in an additional 1.7 million children reached annually with their first MCV dose. If all Gavi-eligible countries switched, that number could jump to as many as 2.3 million children annually. Building on the success of the MCV 5-dose work, Linksbridge is developing global public goods that leverage lessons learned from the 5-dose switch to inform and advance other vaccine portfolio optimization efforts.
