Vaccine Hesitancy: Here to stay? (June Podcast)

By Edward Chen

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Smallpox: 9.37 million search results.

COVID-19: 5.71 billion search results.

Vaccine: 983 million search results.

Hesitancy: 46.3 million search results.

Vaccine hesitancy: 7.9 million search results.

Search results aside, vaccine hesitancy is arguably a phrase that is greater than the sum of its parts. At a minimum, it’s an equal. Is the world concerned about designing vaccines? Or is the world concerned about vaccine hesitancy? A bit more of the first, you might say. But developing vaccines that work without causing harm, while necessary, is only part of the journey to protecting the world from deadly diseases. Vaccines don’t save lives. Vaccinations do. As you probably predicted, this month, we’ll be talking about vaccine hesitancy.

Vaccine hesitancy is an 18th century concept; we may hear more of it more now, but the sentiment has always been around. Ever since there have been vaccines, there have been qualms about them. Even in modern times.

In Boulder, Colorado circa 2002, vaccine hesitancy was so prevalent that whooping cough, a vaccine-preventable disease, caused outbreak after outbreak after outbreak until it was declared endemic to the region. More well-known is the Disneyland measles outbreak that started in California during the last month of 2014. While the term “anti-vaxxer” may have appeared more in the news then, the public health field has been shifting towards the more neutral term of “vaccine hesitancy.” Not everyone who doesn’t get vaccinated is “anti-vaccine,” the newer thinking goes. Because of this, in 2012, the World Health Organization (WHO) established a working group to define vaccine hesitancy and consider alternative terms.

Regardless of what the favored term is, this unsubsiding concept embodied by only two words has concerned physicians, researchers, governments, international organizations, and private citizens from centuries past to today. And, as history has shown, these two words affect everyone in the world. It’s unsurprising, then, that the WHO has listed vaccine hesitancy among the top 10 threats to global health, right up there with the inevitable yet-to-arrive influenza pandemics of the future, crisis-struck areas without basic care, antimicrobial resistance, and “priority diseases” such as Ebola.

We can see the tried-and-tested, real-world, global impact of vaccines. Just name a disease that humanity has completely eradicated, any disease.

What about … rinderpest! That’s true, and was eliminated with vaccines, though it’s not a disease that directly afflicts human beings like you and me. I (and you, too, probably) would first think about smallpox, the only human disease that has been eradicated.

In 1980, the WHO announced that smallpox was wiped off the face of the Earth with the dramatic headline “Smallpox is dead!” This was after over a decade of coordinated, intensive vaccination efforts. In India alone, upwards of 100,000 frontline healthcare workers made over 2 billion house calls. The smallpox vaccine made that possible. But the vaccine alone wasn’t enough; after all, the smallpox vaccine was developed nearly 200 years earlier, in 1796, and other methods to prevent smallpox were known even before then. Public health workers used innovative strategies such as ring vaccination – prioritizing the vaccination of those living near areas with rising numbers of smallpox cases – and people throughout the world had to be willing to receive the smallpox vaccine. The US Centers for Disease Control and Prevention (CDC) no longer recommends childhood smallpox vaccination because of the decisions made by literal billions of people around the world to receive the smallpox vaccine. Smallpox no longer circulates anywhere in the world.

This brings us to COVID-19. As of June 30, 66.5% of adults in the US have received at least one COVID-19 vaccine dose and 57.4% have been fully vaccinated. The numbers are about 3% lower when including all people eligible for the vaccine, which includes children as young as 12, and are about 12% lower when considering the entire US population, which includes those too young to receive the vaccine. Viewpoints on these figures differ and these statistics variously embody hope or despair. New virus variants continue to increase in prevalence. In the first half of this month, the Delta variant, which increases hospitalization rates and spreads 50% faster than previously circulating versions of the coronavirus, accounted for 26.1% of COVID-19 cases. Two weeks before that, it had caused 10% of COVID-19 cases.

Here’s a different perspective: A common-enough goal is to reach herd immunity, when disease transmission is prevented or significantly decreased through high vaccination rates (or, the unpreferred alternative, high rates of natural infection). Depending on who you ask though, achieving that goal is a “yes … in only a few months,” “difficult,” “unlikely,” “probably … unattainable,” or even, “probably impossible.” This is a sharp change in tone from the earlier “can do” attitude and estimates that a vaccination coverage of 60% to 70% would be enough for eliminating or drastically reducing community COVID-19 transmission.

Even though the US vaccine rollout began in 2020 and vaccine eligibility was expanded to all US adults on April 19 of this year, the US still surpassed 600,000 deaths from COVID-19 in the middle of this month. COVID-19 has repeatedly shown that it is nothing if not deadly. Despite these harrowing statistics, vaccine hesitancy appears to be here to stay.

This doesn’t mean, however, that vaccine hesitancy is the only challenge the world faces. Remember smallpox? The supply of vaccines was a significant issue, limiting the access of those very vaccines and introducing the necessity for ring vaccination. With COVID-19, the supply of vaccines is again a significant issue. Wealthier countries with greater financial bargaining power secured vaccine doses even before they materialized, leaving middle- and lower-income nations to fend for themselves in a competition for what few doses remained. Any surge in COVID-19 cases increases demand and inevitably locks up supply within countries like India that are able to make vaccines for themselves. This global inequity concerns the WHO: “High-income countries have administered 69 times