Making Vaccines Available to Other Countries Before Offering Domestic Booster Vaccinations

On July 8, 2021, Pfizer and BioNTech announced they would be seeking US and European authorization for administration of a third booster dose of their COVID-19 vaccine.¹ The same day, the US Food and Drug Administration and the Centers for Disease Control and Prevention emphasized that current evidence does not suggest a need for this booster dose. Other countries, such as Israel, the UK, France, Germany, Sweden, and the UAE are not waiting for further evidence of the efficacy of booster vaccination and will imminently begin offering boosters to large segments of their populations.² These deliberations have focused on important questions concerning vaccine effectiveness against variants of COVID-19. But determining whether administration of booster vaccine doses is appropriate also requires consideration of how marketing campaigns for booster vaccines will affect the global distribution of vaccines.

Large-scale booster vaccination campaigns help amplify the degree of inequality in vaccine access. In constraining the scarce supply of vaccines that could be sent to countries with much lower vaccination rates, these campaigns also increase the likelihood that vaccine-resistant variants will develop, to the potential detriment of the entire world. So long as the current dosage schedule used in vaccination continues to perform well in reducing serious and fatal outcomes against COVID-19 variants, administration of booster doses should be postponed until vaccines are available worldwide.

The concentration of vaccinations in a small group of wealthy countries is well-documented. Due to contractual commitments from advance purchase arrangements and other measures, 10 countries (China, India, US, Brazil, Germany, UK, Japan, France, Turkey, and Italy) have administered approximately three-quarters of all vaccine doses.^3,4 This concentration of vaccinations means the populations of many middle- and low-income countries remain unprotected, and outbreaks in those countries are taking an increasing toll. As of August 10, 2021, 6 of the 10 countries with the most fatalities per capita from COVID-19 in the past week (Tunisia, Georgia, Botswana, Eswatini, Namibia, and South Africa) have less than 10% of their populations fully vaccinated. None of the other 4 (Fiji, Malaysia, Cuba, and Kazakhstan) have fully vaccinated more than one-third of their population.⁴ In short, vaccine inequity translates into disparities in mortality rates from COVID-19.

While efforts to improve distribution of vaccines globally are underway, decisions by high-income countries to provide booster vaccinations will substantially impair those efforts and contribute to COVID-19–related morbidity and mortality. Countries offering booster vaccinations will consume vaccine supply that could have been sent to countries with greater need, despite evidence that the expected benefits of booster vaccinations (ie, reduced hospitalizations and deaths) are small compared with the expected benefits of using those doses on unvaccinated people. For instance, data from the UK, Canada, and Qatar indicate that Pfizer-BioNTech vaccines are well over 90% effective at preventing severe infection against the Delta variant.^5-7 Even if that effectiveness wanes over time, doses of vaccine will provide far more protection against hospitalization and death when administered to unvaccinated individuals than when used as booster vaccinations.

Proponents of booster vaccinations such as Pfizer and BioNTech highlight that 2-dose regimens may be less effective against emerging variants over time, and booster doses could correct for this.¹ However, with constrained global vaccine supply, it is unethical to provide booster vaccinations as long as the existing 2-dose regimen continues to provide effective protection against variants. Even with the Delta variant in circulation, deaths per capita have been concentrated in unvaccinated populations. While it remains to be seen whether vaccines may become less effective against future variants, the current vaccines are still highly protective against infection, hospitalization, and death from currently circulating variants.⁷ This means that the benefit of booster vaccination is eclipsed by the benefit of initial vaccination for vaccinated persons as well as their local community. The comparative benefit of a third vaccine dose may be substantially greater for a small subset of vaccine recipients such as immunocompromised individuals, although the focus herein is on broad-based booster campaigns like the ones sought by Pfizer and BioNTech.

An impartial criterion for the global distribution of vaccines would require delaying booster vaccine doses in favor of sending vaccine to areas highly burdened by COVID-19 infection. But the direct benefits of booster vaccinations would be realized by the country offering vaccination. By comparison, the direct benefits of forgoing a booster vaccination will accrue to individuals in countries with high concentration of COVID-19 infection, who get access to the excess vaccines. Consequently, countries with excess vaccine that prioritize the needs of their residents over others may argue for providing booster vaccinations in their own country, even if the marginal benefits are comparatively small.

To be sure, countries are justified in giving some degree of priority to their own residents due to the special obligations governments have to promote residents’ well-being. But there are moral limits on the extent of this priority.⁸ The interests of those in other countries are still ethically relevant, and at a certain point those needs will outweigh any reasonable national priority. A rough heuristic for when that point is reached is what could be described as the influenza standard. Countries would be ethically permitted to prioritize their own residents as long as this is necessary to make COVID-19 cease to be an emergency. When the disease risk from COVID-19 becomes similar to routine background health risks that are deemed not an emergency and do not warrant significant public health measures, such as lockdowns, limitations on travel, and related restrictions—that is, when COVID-19 becomes more like a bad influenza season in terms of mortality, other health effects, and public health restrictions—then there is no longer an ethical justification for retaining vaccine doses for country residents. At that point, governments should redirect the bulk of their vaccine stock to other countries that have substantially greater need.

Even if countries like the US and UK have not reached the level of a bad influenza season, booster vaccinations are not a meaningful way to achieve that goal. From January 2021 through June 2021, more than 99% of deaths from COVID-19 in the US were among unvaccinated individuals.⁹ Thus, a booster campaign will have little to no effect on preventing the worst ongoing harms from COVID-19. A booster vaccination might have meaningful influence if vaccines lose effectiveness in preventing serious disease over time or with new variants. However, even in those cases, the marginal benefit in one country of shoring up waning protection might be much less in comparison to that of providing doses for unvaccinated individuals in other countries, so long as vaccination continues to protect against the most serious harms of infection. Mortality within a country should be controlled with a focus on immunizing those who are unvaccinated, as well as nonvaccine therapies and public health measures. Booster vaccinations would waste precious vaccines that could save many more lives if distributed to other countries.

Even if the interests of nonresidents in a country were set aside, countries like the US, UK, and European Union member states have strong pragmatic reasons for delaying booster vaccination campaigns. Increased rates of viral transmission, regardless of where they occur, increase the risk that dangerous COVID-19 variants will emerge, which may be more transmissible, vaccine-resistant, or cause more severe illness.¹⁰ By exacerbating the extreme levels of existing inequality in the distribution of vaccine, booster vaccination campaigns could create more chances for the virus to mutate along these lines, thereby potentially worsening the position of all countries in the effort to control the pandemic. Conversely, sending the vaccine doses that would be used for booster vaccinations to places where they could do substantially more good in reducing transmission may decrease the likelihood that more dangerous variants could develop. Well-vaccinated high-income countries should delay booster vaccination in favor of sending doses where they are most needed in other countries, regardless of whether they heed their responsibilities to nonresidents.

The current US position that 2 vaccine doses are adequate will help ensure a booster vaccination campaign does not impede global distribution efforts at this time. But the US reasoning is entirely focused on evidence of benefit from domestic vaccination. The US and other countries must take a broader global perspective when considering booster vaccination programs. While these countries may reasonably prioritize their own residents’ interests, they must not forget the vastly greater need for vaccines among those who are unvaccinated in other countries, as compared with those who have received 2 doses in their country. In addition, these countries must be sensitive to the benefits for their own residents from a world with a more equitable distribution of vaccines, which reduces the chances of a more transmissible or virulent variant evolving.

When there ceases to be a global shortage of COVID-19 vaccines or if existing vaccines can no longer provide substantial protection against new viral variants, booster vaccinations may be part of a reasonable long-term global health strategy. The current situation is not yet close to that point. Hence large-scale booster vaccination campaigns should not be considered at present.

Corresponding Author: G. Owen Schaefer, DPhil, Centre for Biomedical Ethics, Yong Loo Lin School of Medicine, National University of Singapore, Block MD11, Clinical Research Centre, #02-03, 10 Medical Dr, Singapore 117597 (medgos@nus.edu.sg).

Published Online: August 12, 2021. doi:10.1001/jama.2021.13226

Conflict of Interest Disclosures: Dr Schaefer reported grants from the Colton Family Foundation, personal fees from the World Health Organization (WHO), and being a special rapporteur for the WHO Access to COVID-19 Tools Accelerator Ethics and Governance Working Group. Dr Emanuel reported personal fees, nonfinancial support, or both from companies, organizations, and professional health care meetings; and being a venture partner at Oak HC/FT; a partner at Embedded Healthcare LLC, ReCovery Partners LLC, and COVID-19 Recovery Consulting; and an unpaid board member of Village MD and Oncology Analytics. No other disclosures were reported.

Disclaimer: The views presented here are the authors’ own and do not represent the views of any institutions or organizations to which the authors belong.