Opinion: California's new rules allow COVID-positive kids in school. Here's the problem

The California Department of Public Health recently updated its COVID guidance to allow people who have tested positive to exit isolation sooner than before. Specifically, officials say that as long as you are fever-free for 24 hours without the use of medications, and other symptoms are mild or improving, you can exit isolation with a mask on. They also recommend avoiding contact with higher-risk people.

This change came as a surprise to many — and it prompted some outrage when the Oakland Unified School District announced a new policy as a result, one in which students who test positive without symptoms can return to school with a mask on and with the recommendation to avoid elderly or immunocompromised people. This policy doesn’t seem very feasible — and it reflects all that officials still haven’t learned about communicating health risks to the public.

California’s new guidance is inconsistent with the recommendations from the Centers for Disease Control and Prevention, which still advises waiting at least five days from a positive test result before going back out. From both, the recommendation is to wear a mask for at least 10 days, although in California, two negative tests at least one day apart allow you to remove your mask.

Neither guidance is perfect. People can shed virus for more than five days after a positive test. In fact, some studies suggest that peak viral load may now actually be around five days after symptoms start, meaning that following CDC guidelines, isolation could end right when people are shedding the most. As for California’s stance, people can be contagious even without a fever and with only mild symptoms.

The California Department of Public Health’s change was prompted by “the reduced impacts from COVID-19” compared with prior years, per its website. COVID cases recently spiked in California and around the country, and the death rate remains concerning, though much lower than the U.S. peak in 2021. At the same time, much of the public has dropped everyday prevention tools such as masking and testing.

As an infectious disease physician and epidemiologist, I can think of potential justifications for the policy shift in this environment. For example, given that mask use has been low, a policy focused on encouraging masking as a means of leaving isolation earlier could theoretically help stop transmission. The alternative could be that people aren’t bothering to test, particularly if they don’t want to face the decision to isolate when it would inconvenience them. With less testing, we could have more potentially infectious people out in the community maskless — and so guidance that re-emphasizes masks has value.

But whatever the rationale for these changes, it’s a problem that they were not communicated clearly to the public, especially in the midst of yet another COVID-19 surge. There’s no reason public health leadership couldn’t flood broadcast television commercials, social media channels like Instagram or X, or the radio to thoroughly explain California’s policy (and encourage masking, if that was the intent). Instead, we were left with major policy changes presented with unclear logic aside from reassurance that we are in a better place now than in 2020.

With this lack of sufficient explanation, the Oakland school district applied the new state policy to create complicated rules for children. Kids may not be able to apply the rules properly, such as wearing a mask consistently (they tend to be particularly bad at this compared with adults) or avoiding immunocompromised or high-risk people (neither kids nor adults can know exactly who falls into this category around them at all times).

In the four years of the pandemic, we saw how important it is for public health leaders to communicate clearly and often. This builds trust, allows for accountability and helps to set expectations. Poor communication, by contrast, prompts disregard for policy, confusion and the misapplication of guidelines. Given the likelihood of students now testing positive and going to school with imperfect masking and without a way to know who is “high risk,” Oakland’s application of the state guidance may lead to more COVID outbreaks in school communities, or transmission to higher-risk staff and teachers.

The state Public Health Department’s announcement was a troubling missed opportunity because the department has been otherwise exemplary, including in its communications around high-filtration masks earlier in the epidemic. Even before the guidance, I noticed very few people wearing masks, including while noticeably sick and symptomatic, during my travels on both airplanes and buses in the state. A policy statement imploring people to actually test and mask, with the incentive of isolating for less time if you do so, could help reduce transmission.

Public health policies that don’t match what people are willing to do are unlikely to be useful, so trying to maximize compliance while minimizing harms is a reasonable middle ground in our new world of weighing uncertain COVID risks. But without clear communication to tell people how to be safe and why, these efforts will fail.

Abraar Karan is an infectious disease doctor and researcher at Stanford University.