The method ensured COVAX fairly distributed 250 million units of COVID-19 vaccines across 150+ countries – and despite political restrictions on who received them.
Cast your mind back to January 2022. We were amidst a record-breaking global surge in COVID-19 cases, fuelled by the highly contagious Omicron variant.
At this point in the pandemic, mass vaccination shielded many wealthier countries from the disease’s worst effects – driving down death rates and re-energising economies. But low- and middle-income countries still struggled. The previous year, G20 nations had claimed over 80% of the world’s vaccines for themselves.
This imbalance denied poorer countries the protection and newfound freedoms enjoyed by wealthier nations. It further threatened to prolong the pandemic globally. As widely quoted at the time: “No-one is safe, until everyone is safe.”
Dr Battal Doğan, Associate Professor in Economics at the University of Bristol, has now published the vaccine allocation method he designed in 2022 to narrow this gap and help the world find its way out of the pandemic (view the method here).
Overcoming earmarks on COVID-19 vaccines
Doğan designed the method for COVAX – the global initiative that aimed to provide vaccines regardless of a country's wealth.
In early 2022, COVAX faced a growing problem. Around 60% of its doses had been donated by wealthy countries with (often politically motivated) restrictions on which other countries could receive them.
These earmarks hindered COVAX's ability to distribute vaccines based on need. They also violated its ‘no dose left idle’ principle, which demanded minimal waste of the vaccines.
It was in January 2022 that Madhav Raghavan, an economist and technical officer on the COVAX allocation team, contacted Doğan with a plea. He needed help designing a new method for allocating vaccines.
Raghavan worked for GAVI, the Vaccine Alliance, who co-led COVAX with the World Health Organization (WHO), the Coalition for Epidemic Preparedness Innovations (CEPI) and UNICEF.
The standard method for allocating vaccines, serial priority (SP), was ineffective under earmarking. Doğan’s expertise in market design positioned him as an ideal candidate to co-create a new method. Doğan's previous work on resource allocation explored the theoretical basis for deciding ‘who gets what’, and tackled thorny problems, including school admissions.
Re-distributing vaccines
Together with Raghavan, Doğan created the SPIP (serial priority improvement pathways) mechanism. This provides precise, systematic tools for sharing out vaccines in the face of restrictions.
SPIP builds on the standard SP method. SP ranks countries by their current vaccine coverage and prioritises countries with the lowest coverage for doses. With earmarks, however, countries further down the list could get more than they need and leave more vulnerable countries short.
Doğan introduced improvement pathways (IP) to manage earmarks. IP allowed COVAX to transfer excess vaccines from earmarked recipients to countries in greater need.
Doğan and Raghavan made sure that SPIP would allocate vaccines fairly, with high-priority countries getting what they need, and it would minimise waste. Doğan calculates that, if 40-60% of doses are earmarked, 8% more are distributed under SPIP, compared with SP alone.
SPIP in action
The first version of SPIP was ready within just a few weeks of Raghavan’s initial call to Doğan. And two months later, COVAX put it into action.
Between March and June 2022, COVAX allocated over 250 million units of vaccines across 150+ countries. Each unit contained multiple doses. Although levels of earmarking turned out to be lower than first feared, SPIP's flexibility allowed COVAX to manage these restrictions effectively.
SPIP ultimately strengthened COVAX’s efforts to close the vaccine gap and bring the pandemic under control.
For Doğan, the project brought dual rewards: “I enjoyed the intellectual parts of designing SPIP a lot, the theoretical side of things. But I was also very happy that we provided a practical solution to an important real-life problem and helped save lives.
“In the field of market design, we care a lot about practical impact. It’s a subject that can really change the world.”