Measles in Texas, Oscillating Tragedies of the Commons & the Risk of Getting Stuck

Misinformation and vaccine hesitancy is generating tail events that were once thought impossible. Federal policies and funding for childhood vaccination must remain steadfast, or worse is yet to come.

Vaccines Work

Vaccines work. Don’t believe me – just look at this graph, starting with the left panel.

Adapted from Asymptomatic (Weitz, JHU Press 2024), original analysis by Project Tycho as part of its work visualizing vaccination and its impacts in the US.

Each row is a state. The columns are years. The colors denote the number of measles cases per year relative to the maximum in a ~50 year period.

What do you see? Dark intensity going to white.

What does that mean? The US introduced a measles vaccine in 1963. It worked.

Before then, nearly every child got measles. Afterwards, they didn’t. The right panel provides a sense of scale: the maximum number of measles cases in a given year by state. Many tens of thousands of cases per state. Each year, hundreds would die, even more would suffer from brain swelling and long-term harm, and tens of thousands would be hospitalized. All of this went away for decades, except for isolated pockets.

Until now:

https://kffhealthnews.org/news/article/texas-measles-outbreak-escalates-undetected-cases-vaccinations/

This will get worse without immediate action-taking and could get far worse if the incoming HHS Sec. RFK Jr continues to undermine universal vaccination.

Vaccination and Tragedies of the Commons

There are many things we like: clean air, clean water, safe roads, and good schools. But, we don’t always get them. A key reason is that people have fundamentally different views on how to achieve the best outcomes. Perhaps you think that you should be able to do whatever you want, and that if everyone did the same we would all be better off. There’s a problem when our choices affect others and vice versa.

Take a simple example – traffic lights. If you were the only person on the road, you would get to where you were going faster with no traffic lights at all. But you are not the only person on the road. If everyone thought the same way as you and we removed all the traffic lights from city streets then every intersection would be chaos (it’s bad enough during a power outage). As a society, we have decided that restraining individual action (my ability to drive straight through intersections) helps all of us reach our destinations faster and more safely.

A tragedy of commons occurs when individuals left to their own devices make choices that lead to worse outcomes than had they coordinated and opted for some level of restraint.

Vaccines present a particularly stark example of this tragedy. The measles vaccine works so well that when nearly every child is vaccinated, then measles goes away. This effectiveness has been co-opted. There is a growing and coordinated campaign to raise doubts about vaccines and suggest that vaccines cause more harm than disease. This movement then feeds into and interacts with doubts and hesitancy of all kinds: fear of needles, suspicion of health authorities, and alignment with partisan views that sees public health as the enemy.

The end result is that more and more families are choosing non-medical exemptions for opting out of vaccine choice. But this is not just a personal choice. That personal decision deprives others of their choice and of their health and maybe even their lives.

Especially for measles.

Measles is incredibly contagious. A single infectious individual can typically infect 15 others, even in advance of the tell-tale measles rash. (I wrote an entire book on Asymptomatic transmission and its consequences with respect to COVID-19, and this feature of undetected transmission is a very bad thing for control). This means that individual choices about what someone might want to do, e.g., run through that traffic light when alone, have potentially catastrophic societal outcomes when many people make the same decision, e.g., crashing into each other at the light.

Measles is also dangerous.

The MMR(V) schedule means children get their first dose of a two dose series between 12-15 months and their second dose between 4 to 6 years. Parents who decide not to vaccinate their children are potentially exposing their own children and ALL other newborns and infants in their commnity to the risk of a life-threatening disease.

When nearly everyone is vaccinated, then everyone is protected, even those who cannot be vaccinated for medical reasons or are too young to be vaccinated. This is termed ‘herd immunity’. When you choose to vaccinate your child you are helping your child and other children. But when enough people make the ‘personal’ decision not to be vaccinated, then we are all far worse off.

Oscillating Tragedies of the Commons And the Risk of Getting Stuck

Nearly a decade ago, I led a multidisciplinary effort to examine tragedies of the commons. In conventional models, a tragedy of the commons occurs when individuals make decisions based on personal incentives, leading to situations where all are worse off than had they acted together with restraint. Over time, such decisions can transform the world around us and change incentives – typically only after a tragedy occurs. The case of measles and vaccination hesitancy is an unfortunate case study.

If everyone is vaccinated then there is virtually no circulating measles. At that point, perhaps some individuals think the costs of vaccination outweigh the benefits. They think: there is no risk to getting measles. So, why not get the benefits of herd immunity without paying what they perceive as the ‘cost’ of the vaccination (e.g., because they believe – falsely – in a link between vaccines and autism).

When enough people make this decision, then vaccine coverage goes down and the chance of measles outbreaks goes up – rapidly. Outbreaks happen, whether in Marin County a few years ago, or in Samoa (with disastrous consequences), and now in Texas.

Over time, incentives may shift. Individuals may realize that there is a chance of infection, hospitalization or worse, and once again change their behavior and get their unvaccinated children vaccinated (hopefully not too late). Increased vaccine rates can stop measles outbreaks, but we should not have to wait until tragedy strikes to act. And if we are not careful, then the incentives may yet again favor the spread of hesitancy once measles goes away.

The net result of this process is what we termed an ‘oscillatory tragedy of the commons’. The paper is technical, but the takeaway is simple: what we do changes the world we live in. Over time, incentives that may favor cooperation (e.g., get vaccinated) can lead to shifts in incentives that favor defection (e.g., avoid vaccination) which leads to tragic outcomes.

At the time, we described ways in which such oscillations would continue and how certain kinds of feedback could get us into a better place in the long-term.

But now, I am concerned that we will get stuck. A key part of moving away from a bad outcome is awareness of harm. If the forces of misinformation and/or disease data becomes unavailable, then fewer and fewer people will be aware or agree that they must be vaccinated. Such a shift would be catastrophic. The cost will be counted in lives, year after year.

We will go back to the dark shadows in the figure at the top of this post.

We should not let this happen.

Vaccination is needed for everyone, except for those truly medically exempt. The increase of non-medical exemptions puts newborns and infants of family, friends, neighbors, and of families in our communities across the US at risk before they ever had the chance to make a choice.

What can you do? Perhaps one of the most important things is to go to this site to learn more about Vaccines for Children (VFC). For more than 30 years this federal program has provided “free vaccines to children who qualify. About half of American children less than 19 years old receive [a] VFC vaccine.” Spread the word. Everyone matters and cost should never be a barrier to receiving a childhood vaccine.