Why We Should Resist Over-Optimism About Covid-19 Vaccines

Dr. Joshua Liao explains why pinning a full return to normalcy solely on vaccines could alter our risk perceptions, encourage unsafe behaviors, and ultimately prolong suffering from the pandemic.

The world eagerly awaits a Covid-19 vaccine. In the United States, one quarter of Americans are inclined to delay resuming normal activities until a vaccine is available. Public officials have used promising news about vaccine candidates to rally their bases. Vaccine topics–when the first one will arrive, how to ensure it is safe, and who will get it first–dominate the news cycle.

All of this attention reflects a widespread expectation that Covid-19 vaccines will accelerate a return to normalcy, ending the need for measures like social distancing and masking. This optimism is understandable given both the incredible suffering that Covid-19 has caused, and the massive amount of time and resources that the world has committed to ending it.

But it can also be dangerous to pin our hopes on vaccines. As behavioral science teaches us, humans are highly susceptible to optimism bias–the tendency to overestimate the likelihood of experiencing positive events and underestimate the risk of negative ones. In the case of Covid-19, over-optimism about vaccines could distort our risk perceptions, encourage unsafe behaviors, and ultimately prolong suffering from the pandemic.

While vaccines can play a role in controlling the pandemic, they are not silver bullets.

The reason to worry is that optimism bias pervades life. College students can overestimate their test performance and post-graduation starting salaries. People tend to be unreasonably optimistic about marriage, underestimating the likelihood that they will experience a divorce. Small business owners are prone to unrealistic optimism about the chances of their new ventures succeeding. Financial advisors can be too positive in their forecasts, and clients in their willingness to take that advice.

This bias is not confined to pure self-assessment; it also occurs when people compare themselves to others. Nearly three-quarters of college students rate themselves as above-average in leadership ability compared to their peers, while only 6% consider themselves below average in athletic ability. In healthcare, we have observed comparative over-optimism for a number of different health conditions and behaviors. Hundreds of studies done in different settings affirm the same point: humans frequently view themselves through disproportionately rose-colored glasses.

It would be dangerous to view Covid-19 vaccination this way. While vaccines can play a role in controlling the pandemic, they are not silver bullets. But optimism bias can create a mismatch between belief and reality, causing people to overestimate vaccine effectiveness and the protection it gives them. Under a false sense of security, people who are vaccinated could be emboldened to stop masking, social distancing, and limiting the size of their gatherings–measures that would be burdensome and unnecessary under the assumption of immunity. 

Premature choices would be even more alarming for several reasons. We still don’t know how long immunity from a Covid-19 vaccine will last; if anything, coronavirus antibodies seem to wane rapidly after infection. We also don’t know what exactly vaccines will prevent (getting infected versus our ability to infect others) and how effectively (partial versus full prevention). Given the time required to manufacture and distribute vaccines at scale, we also don’t know exactly when vaccines will be available to everyone. These factors all increase the harm that could occur if those who get vaccinated prematurely abandon safe behaviors and precautions.

How can we combat over-optimism about Covid vaccines? In both our public health messaging and social interactions, we can leverage framing effects–the fact that peoples’ decisions are affected by how information about an issue is presented–and change how we talk about social distancing and masking.

So far, even if implicitly, these behaviors have been framed as stop-gap measures, things to tolerate until we get an effective vaccine. The problem is that this framing itself could increase the risk of over-optimism: months of pent-up anticipation about vaccines obviating social distancing and masking could further predispose people to overconfidence.

Instead, we can frame these behaviors as necessary parts of life, even after Covid-19 vaccines arrive. Because of optimism bias and gaps in vaccine knowledge, public officials could use this framing to convey a clear, even if unintuitive, message: that the arrival of Covid-19 vaccines should prompt us to make even greater commitments to behaviors like social distancing and masking–not less.

To be fair, other factors can affect how individuals view Covid-19 vaccines. As a psychological phenomenon, optimism can also be protective, preserving self-esteem and building resilience in the face of adversity. Nonetheless, the problem with over-optimism about Covid-19 vaccines is that it can expose us to unnecessary risks at a time when we should be doing everything in our power to mitigate them.

Resisting optimism bias will help us meet that mark and use vaccines as a tool for achieving our ultimate goal: ending the pandemic as quickly as possible.

Source https://www.forbes.com/