Rethinking COVID-19 vaccine allocation: it is time to care about our neighbours
Authors: Sebastian Contreras, Álvaro Olivera-Nappa, Viola Priesemann
Journal: The Lancet Regional Health - Europe (2021)

The COVID-19 pandemic changed nearly every aspect of our lives. The rapid spread of the disease exposed several layers of inequality that it has exploited to propagate preferentially. We find these layers in different contexts and levels, such as the impossibility to self-isolate and do remote work (at the individual level) or economic constraints to deploy a fast vaccination program (at the country level). In the context of vaccination programmes, resources must be optimised to alleviate the pandemic burden where it is needed the most. In The Lancet Regional Health Europe, Yang Liu and coauthors analyse the health and economic impact of different age-stratified vaccine prioritisation programs in 38 countries of the World Health Organization (WHO) European Region and provide a modelling framework to optimise country-specific vaccine allocation.1Liu Y Sandmann FG Barnard RC Pearson CA Pastore R Pebody R Flasche S Jit M LSHTM CMMID COVID-19 Working Group. Optimising health and economic impacts of COVID-19 vaccine prioritisation strategies in the WHO European Region: a mathematical modelling study.Lancet Regional Health – Europe. 2021; https://doi.org/10.1016/j.lanepe.2021.100267Summary Full Text Full Text PDF PubMed Scopus (21) Google Scholar From early 2021 on, COVID-19 vaccines have helped alleviate the pandemic's burden on society by mitigating contagion, protecting the population against severe disease, and allowing for less restrictive measures, especially in countries with high vaccine uptake and availability.2Contreras S Dehning J Mohr SB Bauer S Spitzner FP Priesemann V Low case numbers enable long-term stable pandemic control without lockdowns.Science Advances. 2021 Oct 8; 7 (eabg2243)Crossref Scopus (20) Google Scholar,3Bauer S Contreras S Dehning J Linden M Iftekhar E Mohr SB Olivera-Nappa A Priesemann V. Relaxing restrictions at the pace of vaccination increases freedom and guards against further COVID-19 waves.PLoS Computational Biology. 2021 Sep 2; 17e1009288Crossref PubMed Scopus (33) Google Scholar,4Viana J van Dorp CH Nunes A Gomes MC van Boven M Kretzschmar ME Veldhoen M Rozhnova G. Controlling the pandemic during the SARS-CoV-2 vaccination rollout.Nature Communications. 2021 Jun 16; 12: 1-5Crossref PubMed Scopus (82) Google Scholar Due to the strong dependency between age and disease severity, age-stratified vaccination was a logical first approach to allocating resources. However, there are several dimensions to consider when optimising vaccine allocation in a given country. Among them, those considered by Liu and colleagues: mortality, morbidity, comorbidity-adjusted life expectancy loss, comorbidity-and-quality-adjusted life-years loss, and human capital loss. Implicitly, talking about vaccine prioritisation forces us to assign human lives (and life quality) a fixed value in our favourite currency. Thus, governments faced a highly nontrivial problem, where the best solution for their societies is not straightforward or homogeneous across countries. Liu's framework allowed policy- and decision-makers to timely evaluate the alternatives that best protect the interests of their nations, considering all the indexes mentioned above simultaneously. Noteworthily, Liu's modelling framework has been available online already since July 2020. During vaccine rollout, some non-pharmaceutical interventions (NPIs) were required to mitigate the spread of COVID-19, with a negative impact on productive sectors and tourism. Notably, these sectors are mostly driven by a young working-class who, despite being unprotected at the beginning of vaccination programmes, is largely expected to keep economies going. Liu and colleagues showed that in countries where vaccination programs are deployed fast and effectively (i.e., vaccinating 80% of their eligible population within one year), prioritising younger adults can be equally beneficial since elder risk groups are also protected when reducing contagion in younger age groups. Therefore, wealthier countries with excess vaccines can reactivate their economies faster if following this alternative. Conversely, countries with low vaccine availability cannot vaccinate the drivers of contagion and thus face a double problem. First, they cannot de facto protect the population at risk, and second, they cannot fully restart their economic activities since they would require NPIs to mitigate the spread of COVID-19, given the low immunity levels across the population. Therefore, differences between vaccination programs will make countries that are already at economic antipodes drift further apart. Since mid-2021, vaccine availability does not pose a problem in high-income countries. Instead, these countries face the challenge that vaccine-hesitant and vaccine-denial individuals pose to the timely completion of vaccination programmes. Often, the lack of individuals willing to receive the vaccine at a given moment has caused the expiration and discard of available vaccine doses.5Feinmann J. How the world is (not) handling surplus doses and expiring vaccines.BMJ. 2021 Aug 25; 374Google Scholar Therefore, it is crucial for these countries to understand the drivers of vaccine hesitancy6Contreras S, Dönges P, Wagner J, Bauer S, Mohr SB, Dehning J, Iftekhar EN, Kretzschmar M, Maes M, Nagel K, Valdez AC. The winter dilemma. arXiv preprint arXiv:2110.01554. 2021 Oct 4.Google Scholar,7Wirtz K. Changing readiness to mitigate SARS-CoV-2 steered long-term epidemic and social trajectories.Scientific Reports. 2021 Jul 6; 11 (-1): 1Crossref PubMed Scopus (3) Google Scholar and implement timely initiatives for re-selling or donating surplus doses to countries where they are needed. The above highlights the need for a coordinated and responsible distribution of vaccines: increased supplies for one country come at the expense of others.1Liu Y Sandmann FG Barnard RC Pearson CA Pastore R Pebody R Flasche S Jit M LSHTM CMMID COVID-19 Working Group. Optimising health and economic impacts of COVID-19 vaccine prioritisation strategies in the WHO European Region: a mathematical modelling study.Lancet Regional Health – Europe. 2021; https://doi.org/10.1016/j.lanepe.2021.100267Summary Full Text Full Text PDF PubMed Scopus (21) Google Scholar Liu's study provides explicit guidance for country-specific optimal vaccine allocation and raises the awareness of regions with excess vaccine resources to consider sharing them before risking them expiring. Liu's framework identifies the optimal strategy for resource allocation within countries. However, we must stop acting and thinking as if the pandemic could be managed locally.8Priesemann V Balling R Bauer S Beutels P Valdez AC Cuschieri S Czypionka T Dumpis U Glaab E Grill E Hotulainen P. Towards a European strategy to address the COVID-19 pandemic.The Lancet. 2021 Sep 4; 398: 838-839Summary Full Text Full Text PDF PubMed Scopus (35) Google Scholar International vaccine inequity is a matter of general concern.9Reddy KS. Boosters appear effective, but are they always needed?.The Lancet. 2021 Oct 29; Summary Full Text Full Text PDF Scopus (3) Google Scholar Moreover, even if governments are interested in principle only in the wellbeing of their nations, helping other less favoured countries might even have advantages in combating COVID-19, e.g. by preventing importing infections when opening their borders, thus minimising the loss of human lives. At times, being generous can be the best way to protect one's own interests.10Burioni R Topol EJ. Has SARS-CoV-2 reached peak fitness?.Nature Medicine. 2021; 27: 1323-1324Crossref PubMed Scopus (13) Google Scholar All authors declare no competing interests. All authors contributed equally to the conceptualization, writing, and editing of this comment. Optimising health and economic impacts of COVID-19 vaccine prioritisation strategies in the WHO European Region: a mathematical modelling studyThe optimal age-based vaccine prioritisation strategies were sensitive to country characteristics, decision-making metrics, and roll-out speeds. A prioritisation strategy involving more age-based stages (V75) does not necessarily lead to better health and economic outcomes than targeting broad age groups (V60). Countries expecting a slow vaccine roll-out may particularly benefit from prioritising older adults. Full-Text PDF Open Access