March 4, 2021 – With the distribution of COVID-19 vaccines increasing and President Joe Biden promising that all American adults will be able to get vaccinated by the end of May, many Americans are finally anticipating the end of the pandemic.
But Arthur Caplan, PhD, a bioethicist at NYU Langone Medical Center, sees the start of a potential new danger: the Peltzman effect. University of Chicago economist Sam Peltzman first described the phenomenon decades ago when he observed that increased safety regulations had no effect on the number of highway fatalities. . It seemed that people were adjusting their behavior to take more risks as they perceived that a situation or threat was becoming safer.
The Peltzman Effect may mean bad news for the pandemic, suggest Caplan and Brit Trogen, MD, a pediatric resident at NYU Langone, in a recent commentary.
“People seem to be settling down [be comfortable] with a certain level of risk, “Caplan says.” And different people accept different levels of risk. When you offer them something that seems to reduce that risk, they often increase the risk in other areas of their life. “
As of March 2, according to the CDC, more than 26 million American adults, or about 10% of the adult population, had received two doses of COVID-19 vaccines.
Once people are vaccinated, one of their first thoughts might be, “I should be more fun,” Caplan says. So they could go inside restaurants or travel, despite the fact that much is still unknown about how the variants of the coronavirus could change the course of the pandemic, or even whether a vaccinated person can still transmit the virus.
Peltzman effect factors
A classic example of the Peltzman effect in action is that if someone drives a car faster after getting new brakes, knowing that good brakes will reduce the risk of a collision. Another example involves the safety of others: One study found that riders passed more closely to cyclists wearing helmets than to those who did not, although these results have been called into question.
Those who study the Peltzman effect cite four things that influence the increase in risky behavior once a situation becomes safer. All four are present with the pandemic, Caplan says.
- The new measure making the situation safer – in this case, the vaccine – must be visible. It’s hard not to notice a hit in the arm or the long queues for inoculation.
- People need to be motivated to engage in risky or previously risky behavior. After a year of lockdown, many are.
- People need to have the control or the ability to increase risky behavior. It’s easier in some states than in others, with some lifting mask mandates and business reopening.
- The new security measure must be effective enough that people feel comfortable doing what they consider risky. New vaccines, with an efficacy of up to 95%, respond to this measure.
What is the answer?
Caplan suggests that the new public health message needs to be clearer and more specific than the previous communication so that the likely increase in risky behavior does not lead us back to high rates of COVID.
People need to know what kinds of precautions they still need to take, like wearing masks and standing back, until more of the population is vaccinated, he says, and researchers are getting more answers on the issue. whether people who have been vaccinated can still spread the virus. The CDC may soon release guidelines on safe activities for fully vaccinated people.
People also need details about gatherings, Caplan says, such as, “If you’re going to have a party, only do it with other people who have been vaccinated.” Grandparents need details on whether it is safe to visit grandchildren and how to handle these visits – with masks or not?
What’s risky in one community may not be risky in another as situations change, says Trogen. “We will increase or decrease our personal preventive behaviors based on the perceived risk of the virus,” she says.
As the number of people vaccinated increases, the misplaced sense of protective “herd immunity” may increase, says Caplan, “long before generalized immunity is really present.”
Its end result: reducing risks, not eliminating them, should be the goal of relaxing security measures. But even if risky behaviors increase, as expected, the change cannot entirely neutralize vaccine safety.
“There will be more risky behaviors, like less mask wearing, and more of all the activities that were reduced, before the vaccination,” acknowledges Peltzman, who edited the article. But will the cases rise again? His prediction: “There will be more cases than if there were no ‘compensatory’ behavior.”
He, too, says public health messages are important and should focus on immunization efforts. “The incentives for riskier behavior won’t go away by telling people what’s risky,” Peltzman says. “The probability of compensation [risky] behavior makes widespread vaccination even more important. “