Trials and Tribulations: The Vaccine Has Arrived
We Need to Tamp Down Our Optimism and Acknowledge the Uncertainty that Comes with Moving From Clinical Trial to the Real World
The vaccines are here! The vaccines are here! If my use of the exclamation point seems a bit over the top, I apologize. I don’t want to be hyperbolic, but I am echoing the tone offered by much of the media and the political classes now that the Pfizer vaccine has shipped and the first doses have been given to frontline workers.
New York Gov. Andrew Cuomo, for instance, described the vaccine as “the weapon that will end the war.” Dr. Chris Dale of Swedish Health Services in Seattle told the Associated Press that we are at “mile 24 of a marathon.”
“People are fatigued. But we also recognize that this end is in sight.”
I’m left wondering if we shouldn’t be tempering that optimism with a little more humility that “it’s a long tunnel, but we can see the light.” Just because you make it to mile 24, does not mean you will be able to drag yourself across the finish line.
Maybe I’m just a natural skeptic, but I’m concerned that we have taken to describing these vaccines as magic bullets. I have no reason to doubt their efficacy. I believe the science, and I plan on being vaccinated when it’s my turn. But we should not allow ourselves to fall into the trap of magical thinking, thinking that if we believe in something it will lead to the outcome we desire.
The available science gives us cause for optimism, but also should give us pause. The logistics of getting viruses to millions of people will be complicated and difficult. The anti-vaccine community is larger and, when combined with the Trump cohort, creates a mass of people who can undermine our efforts. We should not allow ourselves to be seduced into hubris.
Vaccine trials are structured so that they can mimic real-world conditions, but they still are just trials. As Carl Zimmer explained in The New York Times in November, researchers during vaccine trials “vaccinate some people and give a placebo to others. They then wait for participants to get sick and look at how many of the illnesses came from each group.” They do this while controlling for variables that can include age, gender, health, and other issues, and they are designed to measure narrow outcomes. They give us an idea of how effective a vaccine is likely to be and what potential side effects the vaccine are likely to cause, but they cannot account for all of the conditions that exist outside of the trials. The important word here is likely, because it reminds us that the conclusions offered by researchers are their best estimates.
That’s why scientists differentiate between efficacy (in this case 95 percent), which is what trials give us, and effectiveness. Efficacy and effectiveness are measure the same way, using different data. The Centers for Disease Control in Atlanta, the federal agency tasked with studying the spread of the coronavirus, says that efficacy refers to laboratory conditions or clinical trials — or “when a study is carried out under ideal conditions.” Effectiveness refers to less-than-ideal, real-world conditions. “Exactly how the vaccines perform out in the real world will depend on a lot of factors we just don’t have answers to yet,” Zimmer wrote in his Times piece, “such as whether vaccinated people can get asymptomatic infections and how many people will get vaccinated.”
So, the 95 percent efficacy rate — which the CDC describes as the reduction in the number of cases for those who are vaccinated compared to the baseline expectation for those who are not vaccinated — may end up being significantly smaller, though this distinction and the uncertainty it implies should not dissuade us from getting vaccinated.
But it should cause us to rein in the hyperbole, because the kind of language used in this report on ABC News (“life-saving science,” “something more than hope,” “a solution”), while understandable given the difficulties of the last year, could create unrealistic expectations. And that, in turn, could empower anti-vaxxers. Treating the vaccines as an automatic fix, when it is inevitable that there will be some hiccups, will allow the folks who distrust vaccines or assume they are some kind of crazy plot to seize upon isolated problems as they occur and use those problems to denounce the entire vaccine effort.
The other danger of treating the vaccines as magic bullets is that people might assume the “solution” — ABC’s word — is at hand and the entire crisis is over or is nearing its end. This, in turn, could lead people who have grown exhausted and angry to flout the guidelines and rules we have used to prevent this catastrophic pandemic from being even worse than it has proven to be.
Our approach going forward, therefore, should be to engender hope while being realistic, and to make clear both the benefits and shortcomings of vaccination. As with the use of masks, vaccines offer protections to individuals but are most effective when they are broadly applied. As Zimmer explained, vaccines may protect the individual, but they are more effective at “slow(ing) the spread of the virus” and “driv(ing) down new infection rates.” This will “protect society as a whole.”
Scientists call this broad form of effectiveness a vaccine’s impact. The smallpox vaccine had the greatest impact of all, driving the virus into oblivion in the 1970s. But even a vaccine with extremely high efficacy in clinical trials will have a small impact if only a few people end up getting it.
“Vaccines don’t save lives,” said A. David Paltiel, a professor at the Yale School of Public Health. “Vaccination programs save lives.”
Getting the vaccine to large swathes of the public is not going to be easy, especially with a significant number of people — up to a third of Americans, by some estimates — seeing vaccines as an assault on their freedoms or as being responsible for other illnesses. Again, the science says otherwise, but this anti-vax cohort will affected our ability to create herd immunity (an unfortunate label). We can’t ignore them or pander to them. We have to find ways to neutralize their impact, which can only happen through education and honest and open dialogue with the public. We should not oversell the vaccines, but we have to make clear that they are, along with masks and social distancing, an essential tool in getting us back to a version of normal with which we all can live.