Development of prioritization tool to further the role of equity in global COVID-19 vaccine allocation

The equal distribution of coronavirus disease 2019 (COVID-19) vaccines has received significant attention, although the concept of an ‘equitable allocation’ of vaccines has been poorly defined to date. Assessment of the need for vaccine requirements across the world will help understand vaccine equity. This includes vertical equity, which entails prioritizing resources among those with different requirements, and horizontal equity, where countries with similar vaccine needs should have comparable access levels.

Background

Countries and populations worldwide have been affected differently by the COVID-19 pandemic and associated non-pharmaceutical interventions (NPIs), which makes the assessment of needs complex. The ability-to-pay and vaccine manufacturing capacity of countries are most often closely aligned with the global allocation of vaccines compared to the needs. Additionally, despite rapid clinical trials and production of vaccines, only 1% of people in low-income countries had been vaccinated compared to 43% in high-income countries after six months of approval of the first COVID-19 vaccine.

Currently, the scope of methods for allocating vaccines between countries is quite narrow. The COVAX Facility, which was established to support the equal distribution of resources in case of global emergencies, has not been able to access vaccines sufficiently. The emergence of the Omicron variant has further led to high-income countries administering more amount of booster doses as compared to all vaccine doses combined in low-income countries. Therefore, the process of distributing vaccines across countries in case of a global emergency needs scrutiny and improvement.

A new study posted to the medRxiv* preprint server proposed a conceptual framework (COVID-NEEDS) that assessed whether vaccine needs are impacted by social, health, and economic conditions of COVID-19 and associated NPIs.

About the study

The study involved public health practitioners and researchers from several countries and took place in two stages between March and November 2021. The first stage included a Delphi survey for unanimity on the most important country-level factors required to assess the needs for COVID-19 vaccines. The second stage included a discrete choice experiment (DCE) for determining weights for the factors that indicate their importance.

The Delphi survey comprised two rounds. In the first round, the participants were required to list a maximum of ten factors they considered most important while assessing a country’s need for COVID-19 vaccines. All the factors reported by the first group were combined, and those that at least two participants reported were presented to the group in the second round. The participants then had to vote on up to eight factors from the combined list that they considered most important for assessing vaccine needs.

The factors chosen by six or more participants comprised the final set of factors used in the DCE survey. The DCE survey was based on the Potentially All Pairwise Rankings of all possible Alternatives (PAPRIKA) method, where participants were asked a series of pairwise-ranking questions based on two hypothetical countries that had the greater need for COVID-19 vaccine.

Study findings

The results indicated that 28 participants were included in the study who worked across 13 different countries. Director and professor were the most common job titles that were reported. The first round of the Delphi survey revealed 38 factors reported by at least two participants and included in the second round.

Out of the 28 participants, 25 participated in the second round of the Delphi survey. A total of nine factors were reported to have received six votes or more and were included in the DCE survey. Additionally, out of the 25 participants, only 15 were reported to complete the DCE survey, with 36 pairwise ranking questions answered on average.

The results reported that ‘proportion of the overall population not fully vaccinated’ was the most important factor for assessing vaccine needs across countries, followed by ‘proportion of the high-risk population not fully vaccinated’ and ‘health system capacity. The least important factors were ‘COVID-19 deaths per million (cumulative)’ and ‘national vaccine deployment and prioritization plan.’

Furthermore, 14 out of the 15 DCE participants agreed that the ranking of factors seemed correct to them, 12 agreed that the survey was not difficult to understand, 10 agreed that the most important factors that were related to national needs for COVID-19 vaccine were included in the study, and 3 stated that they were unsure.

Therefore, the current study determined that the assessment of COVID-19 vaccine needs was complex. The proportion of the overall population and the high-risk population not fully vaccinated were the most important factors related to vaccine needs. Thus, this scoring tool can help qualitative assessments improve the role of equity in global vaccine allocation. 

Limitations

The study consists of certain limitations. First, the study findings may not represent all experts in the field. Second, the response rate was limited to approximately 50% of the invited experts. Third, most patients were unable to complete the DCE. Fourth, the study was started before %using booster doses which can impact the identified factors and weights in the future. Finally, the amount of contextual detail provided in the DCE survey was limited.

*Important notice

medRxiv publishes preliminary scientific reports that are not peer-reviewed and, therefore, should not be regarded as conclusive, guide clinical practice/health-related behavior, or treated as established information.

Written by

Suchandrima Bhowmik

Suchandrima has a Bachelor of Science (B.Sc.) degree in Microbiology and a Master of Science (M.Sc.) degree in Microbiology from the University of Calcutta, India. The study of health and diseases was always very important to her. In addition to Microbiology, she also gained extensive knowledge in Biochemistry, Immunology, Medical Microbiology, Metabolism, and Biotechnology as part of her master's degree.