Since January 2020 Elsevier has created a COVID-19 resource centre with free information in English and Mandarin on the novel coronavirus COVID- 19. The COVID-19 resource centre is hosted on Elsevier Connect, the company's public news and information website. Elsevier hereby grants permission to make all its COVID-19-related research that is available on the COVID-19 resource centre - including this research content - immediately available in PubMed Central and other publicly funded repositories, such as the WHO COVID database with rights for unrestricted research re-use and analyses in any form or by any means with acknowledgement of the original source. These permissions are granted for free by Elsevier for as long as the COVID-19 resource centre remains active. G Model ARTICLE IN PRESS Med Clin (Barc). 2021;xxx(xx):xxx–xxx www.elsevier.es/medicinaclinica Editorial article Who should be vaccinated against COVID-19 first?夽 ¿A quién habría que vacunar primero frente a la COVID-19? Rafael Dal-Ré a,∗ , Victoria Camps b a Unidad de Epidemiología, Instituto de Investigación Sanitaria, Hospital Universitario Fundación Jiménez Díaz, Universidad Autónoma de Madrid, Madrid, Spain b Departamento de Filosofía, Universidad Autónoma de Barcelona, Barcelona, Spain A few weeks ago, the media reported that the WHO had estab- the maximisation of health and economic benefits should guide the lished a fundamental principle in the fight against COVID-19: the case. vaccines that prove to be safe and effective must be distributed in Assuming that vaccine production will be staggered and all countries in order to control the transmission of SARS-CoV-2. embracing the surrounding great uncertainty — how should the Poor countries should receive the needed vaccine doses coequally first available doses be distributed and to whom? with rich countries; since the vaccine production will be staggered, The COVID-19 vaccines are a global public good.4 For the WHO, it will be necessary to prioritise which population groups should during the time that the vaccine production capacity is limited, be vaccinated first to maximise social benefit. the basic initial objectives are to reduce mortality and protect In order to ensure that this is fulfilled, a global collaboration health systems.5 The principles to consider are5 : protect and pro- was created for the development, manufacture and equitable dis- mote human well-being; recognize the dignity of all people and tribution of COVID-19 vaccines, called COVAX. This is a partnership treat them accordingly; ensure equity in access to vaccines; gen- of countries, philanthropic foundations and pharmaceutical com- erate reciprocity with people and groups that present significant panies etc. COVAX is directed by the World Health Organization additional risks against SARS-CoV-2; and make global/national (WHO), Global Alliance for Vaccines and Immunization (GAVI) and decisions on vaccine allocation in a transparent way, based on the Coalition for Epidemic Preparedness Innovations (CEPI). Its goal is to best available evidence and taking into consideration the affected obtain two billion vaccine doses before the end of 2021, less than parties. half of the possible world production,1 to ensure delivery to coun- Under these premises, the WHO has identified which popula- tries that will either receive them for free or pay for them.2 The tion groups should be prioritised to maximise the benefit of having latter countries can request amounts to cover between 10 and 50% to administer a limited number of vaccine doses, regardless of the of their population.2 Poor countries will receive 1 billion doses for seroprevalence achieved in each country: social health workers free.1 184 countries have joined the initiative,3 including those of — because when caring for and treating patients with COVID-19 the EU and China, but not the US. The allocation of vaccine doses these workers are in close contact with them; and people over for each country will be proportional to their populations, with the 65 and those with certain comorbidities — because they have a exception that no country should receive doses that exceed 20% of higher risk of dying from COVID-19.6 In a first phase, all the coun- its population until all have reached that percentage.2 tries should receive a quantity of vaccines proportional to their Epidemiological and ethical criteria are used to achieve the population: doses for 3% of the population make it possible to vac- objective that all countries receive sufficient doses of COVID-19 cinate the social health workers of each country; with additional vaccines. According to epidemiology, as long as the transmission doses to reach 20% of the population, those over 65 years of age of SARS-CoV-2 is not controlled in the majority of countries and and those under this age with comorbidities may be vaccinated. among the world’s population, the pandemic will be present or may In addition, countries should receive sufficient amounts to attend reappear. Therefore, thanks to the vaccine (and to a lesser extent, humanitarian situations such as displaced persons and refugees.6 the infection), group immunity can be achieved and thereby break Once these priority population groups have been vaccinated, coun- the chain of transmission. From an ethical point of view, equity and tries can receive more doses to vaccinate the rest (>20%) of the priority population and, finally, include every person each coun- try considers can benefit from vaccination. The prioritisation and quantification of the vaccine doses to be received in each alloca- 夽 Please cite this article as: Dal-Ré R, Camps V. ¿A quién habría tion round should be based on the potential impact of COVID-19, que vacunar primero frente a la COVID-19? Med Clin (Barc). 2020. https://doi.org/10.1016/j.medcli.2020.11.001 according to epidemiological data (e.g. basic reproduction number, ∗ Corresponding author. E-mail address: Rafael.dalre@quironsalud.es (R. Dal-Ré). https://doi.org/10.1016/j.medcle.2020.11.005 2387-0206/© 2020 Elsevier España, S.L.U. All rights reserved. MEDCLE-5488; No. of Pages 3 G Model ARTICLE IN PRESS 2 R. Dal-Ré, V. Camps / Med Clin (Barc). 2021;xxx(xx):xxx–xxx Ro), and on the vulnerability of the country’s health system (e.g., benefit, every person be considered and treated as having equal occupation of hospital and ICU beds).6 dignity, worth, and value, and the mitigation of health inequities.13 The WHO proposal to use population-based proportionality for The allocation must be carried out taking into account three the allocation of vaccine doses has been questioned by those who procedural principles13 : fairness in prioritisation, transparency and support the Fair Priority Model.7 As a fundamental ethical principle, being based on evidence. Taking into account four allocation crite- this model defends benefiting people and limiting harm, prioritis- ria (risk of acquiring infection, risk of severe morbidity/mortality, ing those who are disadvantaged and recognising that all people risk of negative societal impact and risk of transmitting infec- have the same dignity. The model focuses on three types of harm tion to others), four allocation phases are proposed. In phase caused directly or indirectly by COVID-19: death and permanent 1a, vaccination would be for high-risk health, transportation and organ damage, health care system strain and stress (e.g., increased environmental services professionals (representing 5% of the US mortality rates from other pathologies) and economic destruction population); phase 1b includes high-risk patients (with at least (e.g., increased unemployment, poverty and hunger). two comorbidities such as cancer, severe cardiovascular disease, The Fair Priority Model proposes three phases in which the pri- chronic obstructive pulmonary disease, obesity, type 2 diabetes) ority is to prevent the most urgent harm.7 Phase 1 aims to reduce and those over 65 years of age who live with many people (e.g., premature death, something especially present in the poorest elderly nursing homes, prisons), which represent 10% of the pop- countries, and other irreversible direct and indirect health impacts. ulation. Phase 2 includes workers in schools, food services, public Premature death is measured using the standard expected years of transport and other services, patients at moderately high risk (with life lost8 (SEYLL) averted per dose of vaccine. SEYLL considers ear- only one comorbidity), adults who live with many people (e.g. res- lier deaths to be particularly important, and values a life saved at idences for the disabled) and those over 65 years not included a given age identically across countries, regardless of differences in phase 1 (they represent 30%–35% of the population). Phase 3 in national life expectancy. In phase 2, in addition to irreversible includes young adults, children, and industrial workers who are harm to health, the proposal includes a reduction of economic and at moderate risk of exposure to SARS-CoV-2 (they account for social deprivations. In this phase, the averted SEYLL is retained as 40%–45% of the population). Phase 4 would include everyone resid- a health measure, and the reduction of absolute poverty and Gross ing in the US who had not had access to the vaccine. National Income (GNI) as measures of economic improvement. In Spain’s central and regional governments are agreeing on a phase 3 the objective is to reduce community transmission, which plan to prioritise the distribution of vaccines,14 and this must will facilitate economic and social activities to the pre-pandemic include to whom it will be allocated15 and how it will be dis- levels. For this model, countries with high Ro rates have prior- tributed, as the logistics are complex. It seems that the allocation ity. All countries should receive the number of doses of vaccines to each autonomous community (CC.AA.) will be proportional to necessary to achieve group immunity. Three objections are raised the population,14 it should be taken into account that the presence regarding the Fair Priority Model7 : (a) the misuse that some may of marginal groups (e.g., immigrants) and those at risk is uneven make of vaccines due to lack of infrastructure or corruption; (b) between the CC.AAs. People at higher risk and health professionals negativity towards assigning vaccine doses to countries that have are likely to have priority.14 Between December and the summer effectively known how to control the transmission of SARS-CoV- of 2021, Spain could have 31 million doses to vaccinate 15.5 mil- 2 (Ro < 1) and (c) difficult to calculate assessment metrics (e.g., lion citizens.16 Initially, three million doses are expected,14 which SEYLL). would be enough to vaccinate the social health workers (there However, from an ethical point of view, one has to be in agree- are about 900,000 health workers17 ) in the coming winter. Span- ment with the Fair Priority Model compared to that of the WHO, ish society has the right to know about the remaining doses from since the equitable distribution of a good such as vaccination must the first shipment and to which risk groups they will be adminis- adhere to the principle of benefiting the least advantaged, as stated tered. by Rawls’s Difference Principle,9 and not taking the population cri- Whatever the answer is and due to the precarious situation terion as an allocation measure. Given the great inequalities that we find ourselves in, the plan in question will require the col- exist between countries, the only way to correct them is not by laboration of all those involved and (e.g., scientific societies) of giving everyone the same, but by giving more to those who are the public.5,13,18 It should be publicly available for the sake of worse off. Beyond ethics, Emanuel et al.7 see other drawbacks in the transparency5,13 and to avoid time-wasting discussions. Commu- WHO proposal; they think that it has not been empirically proven nication in this regard is essential for the population to know and that vaccinating health workers and those most at risk of dying understand the reasoning behind certain priorities regarding access will optimally reduce mortality from COVID-19. At the opposite to vaccination. At the same time, and given that 44% of the pop- extreme, the models of Hogan et al.10 show that the most efficient ulation state that they are not willing to be vaccinated within a way to prevent mortality from COVID-19 is to assign vaccine doses few months of being able to do so,19 it is important to report on in proportion to the population of each country. When doses are the usefulness of the vaccine, when we have access to vaccines available to vaccinate less than 20% of the population, their mod- that, although they can reach only 50% efficacy,20 will be essential els indicate the suitability of vaccinating those over 65 and those in to control COVID-19. Addressing the distribution of vaccines with high-risk groups. However, when a country has a sufficient number transparency and a sense of responsibility is essential to ending of doses, the best option would be to vaccinate people of working successfully the social and health crisis in which we find ourselves. age, instead of those over 65, as group immunity would be achieved earlier,10 something that is unlikely to happen given the staggered availability of anticipated vaccine doses. Funding If we stop thinking about assigning vaccine doses globally and focus on how to do it in developed countries, what should the crite- This work has not received any type of funding. ria be? Three documents have addressed this issue.11–13 The most extensive and detailed draft is the National Academies of Sciences, Engineering and Medicine from USA13 ; it explains that the objective of vaccine allocation is to reduce severe morbidity and mortality, Conflict of interests and negative societal impact due to COVID-19. The proposed frame- work is based on three foundational ethical principles: maximise The authors declare that they have no conflict of interest. G Model ARTICLE IN PRESS R. Dal-Ré, V. Camps / Med Clin (Barc). 2021;xxx(xx):xxx–xxx 3 References 12. UK Department of Health & Social Care. https://www. gov.uk/government/publications/priority-groups-for-coronavirus-covid- 1. Callaway E. The unequal scramble for coronavirus vaccines. Nature. 19-vaccination-advice-from-the-jcvi-25-september-2020/jcvi-updated- 2020;584:506–7. interim-advice-on-priority-groups-for-covid-19-vaccination, 2020. 2. OMS, GAVI y CEPI. COVAX. https://www.gavi.org/covax-facility. 13. National Academies of Sciences, Engineering, and Medicine, ISBN: 978-0- 3. Sharma R. https://medicircle.in/184-countries-have-joined-covax-facility-who, 309-68224-4. https://www.nap.edu/catalog/25917/framework-for-equitable- 2021. allocation-of-covid-19-vaccine, 2020, https://doi.org/10.17226/25917. 4. Yanus M, Donaldson C, Perro JL. COVID-19 vaccines a global common good. 14. García LB. https://www.lavanguardia.com/politica/20201016/484107028177/ Lancet Health Longev. 2020;1, e6–8. salvador-illa-vacunas-30-millones-covid-19-principios-ano.html, 2020. 5. World Health Organization. https://apps.who.int/iris/handle/10665/334299, 15. Mahase E. Midwives and paramedics can deliver flu and covid vaccines after 2020. new laws come into force. BMJ. 2020;371:m4044. 6. World Health Organization. https://www.who.int/publications/m/item/fair- 16. Sevillano E. https://elpais.com/sociedad/2020-10-20/sanidad-empleara-56- allocation-mechanism-for-covid-19-vaccines-through-the-covax-facility, millones-de-euros-en-vacunar-contra-la-covid-a-15-millones-de-personas- 2020. entre-diciembre-y-junio.html, 2020. 7. Emanuel EJ, Persad G, Kern A, Buchanan A, Fabre C, Halliday D, et al. An ethical 17. Instituto Nacional de Estadística. https://www.ine.es/prensa/epsc 2019.pdf, framework for global vaccine allocation. Science. 2020;369:1309–12. 2020. 8. Marshall RJ. Standard expected years of life lost as a measure of mortality: norms 18. Braunack-Mayer AJ, Street JW, Rogers WA, Givney R, Moss JR, Hiller JE, et al. and reference to New Zealand data. Aust N Z J Public Health. 2004;28:452–7. Including the public in pandemic planning: a deliberative approach. BMC Public 9. Rawls J. La justicia como equidad. Una reformulación. Barcelona: Paidós; 2001. Health. 2010;10:501. 10. Hogan AB, Winskill P, Watson OJ, Walker PGT, Whittaker C, Baguelin M, et 19. Centro de Investigaciones Sociológicas. http://datos.cis.es/pdf/Es3296marMT al. https://www.imperial.ac.uk/mrc-global-infectious-disease-analysis/covid- A.pdf, 2020. 19/report-33-vaccine/, https://doi.org/10.25561/82822. 20. Krause P, Fleming TR, Longini I, Henao-Restrepo AM, Peto R, WHO Solidarity 11. Toner E, Barnill A, Krubiner C, Benstein J, Privor-Dumm L, Watson M, Vaccines Trial Expert Group. COVID-19 vaccine trials should seek worthwhile et al. https://www.centerforhealthsecurity.org/our-work/pubs archive/pubs- efficacy. Lancet. 2020;396:741–3. pdfs/2020/200819-vaccine-allocation.pdf, 2020.