The WHO reported over 30,000 cases of measles in the European Region in 2023, up from less than a thousand in 2022 – a 30 fold increase. This year is already looking to have an increase in measles in many regions, with outbreaks noted in Chicago, Sacremento, and the UK.
There have been 41 cases so far in the US this year, while there were 58 cases for all of 2023. In 2000 measles was declared eliminated from the US. That means it is no longer endemic, with all new cases being imported from outside the US and immediate spread from those cases (causing outbreaks) but no continuous spread. However, if we have continuous outbreaks for a year or more the US will lose its “eliminated” status, and we have been on the brink of this happening in recent years.
This story, of course, is all about the measles vaccine – MMR. This is a safe vaccine that effectively prevents infection with measles, which is otherwise a highly contagious disease. Measles is a serious infection, that also weakens the immune system, making those infected more susceptible to other infections.
The good news is, we have an effective MMR vaccine program in the US (part of the overall childhood vaccine program) – by 24 months of age 90% of children are vaccinated against measles, and by teenage years the number is 92%. That’s good for any public health program. However, because measles spreads so easily, it is estimated that we need 95% coverage in order to achieve herd immunity, the level at which the disease can no longer spread through a population.
Also, total percentages may be misleading, because local communities may have lower vaccination rates. In Chicago, for example, where the CDC just sent people to help contain an outbreak, they warn that vaccination rates have dipped from 95% to 93%. This is just enough to go below herd immunity. In other locations experiencing outbreaks the numbers are worse – the UK has about an 85% vaccination rate against measles, far below herd immunity levels.
In some parts of the world vaccination is about resources, but even in poor countries there are international programs to fund vaccination. The real challenge is in getting >95% of people to do something. We can lower the barriers by making it free and easy, we can do public education and outreach. Such measures get you to the UK level of about 85%.
The evidence is pretty clear and overwhelming – in order to get >95% of people to do something, even something that is in their own personal best interests, is to mandate it. That is the difference between the US and the UK numbers – childhood vaccines are mandated in the US in order to attend public school, and they are not in the UK. This is also why the UK lost their measles elimination status while the US (so far) has not.
In the US, while we have mandatory vaccines for school entry, the various states also have different rules for exemptions. This creates 50 natural experiments – and the result clearly show that looser rules for exemptions result in decreased vaccine uptake and increased risk of outbreaks of vaccine-preventable diseases.
And of course there is another factor at play here – this is not just about getting people to be responsible about their preventive health care, there is also an active anti-vaccine movement spreading fear and misinformation. This misinformation spreads easily across social media, which also fuels general conspiracy theories and distrust of authorities, experts and institutions. The primary cause of vaccine hesitancy is viral misinformation.
This causes a genuine dilemma for free societies. The Supreme Court recently heard a significant case in which the 5th circuit appellate court ruled the government violated the first amendment when it “significantly pressured or coerced” social media companies to remove misinformation about COVID-19 from their platforms. This is a complicated case I can’t do justice here – but the issues involve the right of citizens to say things in the public square that are objectively wrong, even harmful, the governments duty to protect the public vs their power to suppress speech, and the degree to which social media companies are private entities with their own free speech (manifest through editorial policies). Further, if the government pressures a social media company to take down a post, does the social media company become an agent of the government, triggering the first amendment? If so, then how does the government protect its citizens from harmful misinformation?
Recent measles outbreaks and the MMR vaccine uptake are on the front lines of this issue. That 2-3% variance which can take us above or below herd immunity is likely a result of misinformation on social media. Also, there were likely thousands of deaths from COVID directly due to misinformation on social media.
At the same time, we see (with China, for example) that a totalitarian government can effectively use social media and digital technology to tighten their grip on society and create an overwhelming surveillance state. In short, sometimes giving the government the power to do good, also gives them the power to do bad.
There is therefore no simple solution, but that does not mean we should stop searching for one. At the very least this means finding the proper balance of the current factors at play – social media companies, the government, and free speech. But we likely will have to search for methods that allow for the identification and removal of demonstrably false and harmful information that represents a direct risk to public health, without violating free speech or giving any entity too much power to act unilaterally. This will likely mean that we need a process that has total transparency, and significant checks and balances.
The other factor here is the degree to which we can collectively mandate certain behavior. This already exists – see the entire legal system. We have speed limits, seatbelt laws, public health regulations, environmental protection regulations, and countless other laws and regulations that prohibit or mandate certain behaviors. The general legal rule is that the government has the burden of demonstrating a compelling interest in fulfilling its duties to the public to justify any restriction of personal liberty, and that the government is taking the least restrictive option to achieve its goal.
Personally I think that mandating vaccines that have been proven safe and effective, and limiting exemptions to medical reasons, fulfills these criteria. Without such mandates we can expect to be increasingly plagued by measles and other vaccine-preventable infectious diseases.