Aaron Schwid, an international human rights attorney, is the director of public health law at Vital Strategies. Tom Frieden, former director of the Centers for Disease Control and Prevention, is president and chief executive of Resolve to Save Lives, an initiative of Vital Strategies, and senior fellow for global health at the Council on Foreign Relations.

With the authorization of a second effective vaccine against the coronavirus, we can imagine an end to the pandemic, like voyagers on a ship seeing the safety of shore.

But it will take many months before we reach the end of this perilous journey, and the public is increasingly losing patience with broad restrictions on day-to-day life. So as more and more people are vaccinated, it’s time to carefully design a system of “immunity passports.”

These passports would serve as a form of proof of immunity, allowing people who have immunity to engage in some activities others cannot. That could make it possible to ratchet down protective measures, such as stay-at-home orders and business closures, without increasing health risks. A venue could finally reopen to some performers, fans and staff. Visitors could return more freely to nursing homes and prisons. International travel could increase.

Versions of these passports already exist. Travel between certain countries requires proof of yellow fever vaccination. Measles and other vaccines are mandatory for school admission. Hospitals and nursing homes require that staff get an annual flu shot.

Distrust in the Trump administration has turned into distrust of science, adding to an already powerful anti-vaccine movement. (The Washington Post)

Immunity passports for covid-19 — although controversial for scientific, practical and ethical reasons — are already being developed. We need minimum standards to get this right.

First, the scientific issues. Any program should be explicit about what a passport means. Neither vaccination nor infection is a guarantee of protection against getting or spreading covid-19. Although results from clinical trials of the three leading vaccines have been overwhelmingly positive, robust data are not yet available on vaccine efficacy in different age groups, races and ethnicities, pregnant women and for those with certain medical conditions. Nor is it known how long immunity will last or whether vaccinated people can spread the virus.

Should the approximately 18 million Americans who have recovered from documented covid-19 infections get an immunity passport, too? Unfortunately, we don’t know enough about natural immunity to certify how long and to what extent someone is protected after recovery. More accurate immunity tests and studies to better understand immunity after infection are urgently needed before we issue any form of passport after infection. Providing passports to people who recovered from natural infection may create a perverse incentive for people to get infected intentionally, especially if they perceive a low personal risk from illness. Policies should not encourage healthy people to risk infection. The more than 300,000 Americans who have died and the 100,000 currently hospitalized are a stark reminder of the danger of natural infection. But if infection is found to confer strong, long-term immunity, we could reallocate some vaccines while they’re still in short supply.

Second, we need practical and universal standards to verify who has been vaccinated. The United States currently uses a paper-based system (upon receiving the vaccine, people receive a coronavirus vaccination record card with basic information on it) with few security features that could serve as a trustworthy, official certificate. Nothing prevents these documents from being lost or stolen, and the opportunities for and consequences of fraud are high.

Technology can solve some of these issues. Recipients can opt for a digital certificate in some jurisdictions, but this creates its own challenges. The personal data collected raise privacy and security concerns, and the potential for misuse of data could dissuade some people from getting vaccinated. Everyone needs to be able to know and control what happens with their personal data. They should also have the choice of opting in to receive a digital certificate or not. We need appropriate, trustworthy and consistent standards rather than a patchwork of policies and digital tools to guide these systems and their application.

The third issue is fairness: Vaccines aren’t available to everyone immediately. People with early access to vaccines would enjoy the benefits of both health protection from immunity and the advantages of immunity passports. This could amplify existing inequities if the already privileged jump the vaccination line. This issue is best addressed by increasing production of vaccines and prioritizing universal, free and rapid access.

Without national guidance on who is protected and what that means, too many will draw their own faulty conclusions. Until we learn more, everyone — vaccinated or unvaccinated, previously infected or not — should continue to protect themselves and others by following the “three W’s”: Wear a mask, watch your distance and wash your hands. Continued masking is important because of the uncertainties about protection. It also simplifies enforcement of mask mandates and supports the social norm of wearing a mask.

As vaccination is rolled out and we learn more about immunity after natural infection, providing the option of an immunity passport to those who choose to receive one can increase freedom of movement for passport holders and accelerate broader social and economic recovery. As universal vaccination becomes available, passports will help everyone, not just the lucky few, move from fear to freedom.

Read more: