By Ana V. Diez Roux, MD, PhD, MPH

Many years ago as a pediatric resident in Buenos Aires I walked through Ciudad Oculta vaccinating against measles. Ciudad Oculta (literally “Hidden City”) was (and still is) a sprawling neighborhood constructed of cinder blocks, occasional bricks, and tin roofs. It had no formal streets or paving, just a handful of dirt roads (the main streets) and a maze of zig zagging paths that made their way deep into the heart of the neighborhood. Many houses had no running water, and electricity was often “borrowed” from the main lines nearby, carried on improvised connections draped over the tin rooftops.

That year there was a measles outbreak. I was rotating through the health center attached to the neighborhood. The health center occupied the bottom floor (the only finished floor) of a mammoth 12-floor building originally designed as a hospital, but abandoned for unclear reasons before construction was finished. The cement structure of the building butted into the sky above the neighborhood like the skeleton of some sort of prehistoric being and signaled from a distance where Ciudad Oculta lay.

We had seen many children at the health center that season with measles. Measles can be deadly especially among children who are malnourished (as many were) or who have other health problems. When a certain number of cases were detected, the city declared an emergency and vaccination campaigns were launched. As pediatric residents we were assigned to go house to house in the neighborhood vaccinating every child 9 months or older. I remember being amazed at how we were welcomed in every home we visited, young and inexperienced (in medicine and in life) as we were, “los doctorcitos” they called us. I don’t recall anyone refusing the vaccine.

Vaccination is probably one of the simplest public health interventions and also one that has immediate measurable impacts. The beauty of it is that it protects not only the recipient but also the community to which the recipient belongs (even if not everyone in the community is vaccinated). It’s a perfect example of the synergistic effects of group-level and individual level factors (I often used herd immunity as an example of a “contextual effect” when I began to think and write about multilevel analysis). Vaccination is in many ways public health in its essence and at its best.

One would think, perhaps somewhat naively, that as a society we would be ready to take on a mass vaccination campaign. After all we have the ingenuity and the skill to organize and coordinate so many complicated tasks. And yet somehow the apparently simple process of organizing and implementing a vaccine delivery system that is rational and fair has proven to be out of our reach. This has been true worldwide (although it is true that some places are doing better than others). In the United States each state (and sometimes even individual cities) has its own distinct allocation criteria, the delivery systems have been a hodge-podge of evolving and opportunistic approaches cobbled together, and changing and often unpredictable vaccine availability has made it almost impossible to plan any systematic approach.

It is no surprise that in the absence of a strongly enforced consistent strategy those with the means to navigate the system can “jump the line” using ethically questionable strategies or making the case that they are deserving because they need the vaccine more or simply because they want it more. As a result we have seen predictable inequities in who has received the vaccine: in the United States, for example, evidence of race differences in vaccination rates is quickly emerging. Data is scant but inequities in vaccination rates are undoubtedly present in other countries too: in Argentina, for example, the minister of health recently resigned in the so-called “VIP vaccine” scandal in which well-connected friends found ways to access a very limited supply. Similar scandals are emerging in other countries.

Many factors are making vaccine distribution especially challenging: very limited vaccine availability, misinformation, understandable mistrust in some communities rooted in historical experiences with the health system. But most fundamentally, the challenges we are facing in allocating vaccine and in getting the vaccine first to those who need it most reflect the systems within which public health efforts are operating.

These include fragmentation of health care systems (which could be a natural vehicle for vaccine distribution, countries with universal health care systems appear to have higher vaccination rates), as well as chronic underfunding of public health departments (which are now expected to implement pandemic-related regulations, conduct testing, administer vaccines, conduct education campaigns, and collect and make available timely and accurate data on multiple aspects of the evolution of the pandemic, all on a shoestring budget!).

It is not the first time that access to a life saving or health enhancing resource is quickly patterned by race and class, these are “fundamental social causes” at work. As elegantly articulated by Link and Phelan years ago: “the essential feature of fundamental social causes, is that they involve access to resources that can be used to avoid risks or to minimize the consequences of disease once it occurs.” Link and Phelan define resources broadly to include money, knowledge, power, prestige, and interpersonal resources embodied in social networks. In class-based and racist societies, both class and race are fundamental social causes of health and disease.

Gross inequities are also present globally across countries and will likely increase over time despite many calls against “vaccine nationalism”: wealthy nations have snatched up or reserved vaccine necessary to cover their populations several times over, while more than 200 countries have yet to administer a single dose. In the words of WHO Director Tedros Adhanom: “The world is on the brink of a catastrophic moral failure, and the price of this failure will be paid with the lives and livelihoods in the world’s poorest countries.” Fundamental social (and economic) causes act across countries too.

Late last summer I served on a National Academy of Medicine Committee charged with developing a framework for vaccine allocation with attention to equity. The committee had many spirited zoom discussions about ethical and public health criteria for allocation, about equity and fairness, about logistics, about support and education campaigns, about outreach. I now see that we were so optimistic….. It is sad and sobering to see many of the problems and pitfalls we hoped to avoid by developing guidelines and processes in advance manifested today not only in the U.S. but across the world. Hopefully things will get better as more vaccine becomes available, but there is no doubt that inequities in access (and inequities in health) will persist unless we finally grapple with what the COVID-19 vaccine experience is telling us about our health care systems, our public health infrastructure, and our social and economic systems more broadly.