Nearly two full years into the global COVID-19 pandemic, and in the middle of an Omicron surge, major U.S. companies are making moves to reduce paid leave for employees who test positive for COVID-19.

CVS and Walgreens are the latest to join a growing list of major companies that are limiting paid time off for all employees who come down with the virus. They join others like Amazon, Delta Air Lines , Ikea, Kroger, and Walmart.

Notably, CVS and Walgreens both told Fortune that they cut paid COVID sick leave based on the CDC’s late-December guidance that people with COVID isolate for five days, versus their previous guidance that they isolate for 10 days, hinting at a possible new corporate trend, and highlighting the lack of standard sick leave policies in the U.S.

In the case of CVS, that paid leave is available only to employees who are vaccinated, approved for a reasonable accommodation, or otherwise covered by local laws. “In line with changes to CDC guidance, we are currently providing five days of paid leave for eligible full- and part-time colleagues, except where state or city paid leave laws provide for more,” a company spokeswoman told Fortune.

Walgreens will be providing COVID sick leave pay benefits for five days to both vaccinated and unvaccinated team members through Feb. 23. After that, Walgreens will provide COVID pay benefits only to employees who are fully vaccinated or have an otherwise approved medical or religious exemption.

The latest cuts to paid sick leave policies are a reminder that the U.S. does not have a federal standard for paid time off. “It’s unconscionable and a real risk to health within workplaces, as well as the health for the consumers that shop in these stores,” says Vicki Shabo, a senior fellow focusing on paid leave policy at the progressive think tank New America.

Only about half of U.S. hourly workers report having access to paid sick leave at their jobs, according to the latest report from the Shift Project, which surveyed U.S. workers in the fall of 2021. Only about 45% of those who contracted COVID reported having paid sick leave.

“Workers tell us that faced with either working sick or going without pay, all too often they have no choice but to work through illness. These frontline workers deserve better,” says Daniel Schneider, professor of public policy at Harvard University and co-lead of the Shift Project.

More than a dozen states and two dozen cities require employers to provide short-term paid sick time. Currently nine states and Washington, D.C., have passed longer paid family and medical leave programs and are at various stages of implementation, according to the Center on Budget and Policy Priorities.

The Democrats’ Build Back Better agenda included four weeks of paid family and medical leave for U.S. workers, but the provision was unlikely to make it into the final bill, and now the entire legislative package remains stalled in the Senate. America is the only industrialized nation with no paid family leave program.

In March 2020, Congress passed the Families First Coronavirus Response Act—which, among other provisions, provided up to two weeks of paid sick leave for workers infected with COVID—and is estimated to have prevented 400 COVID cases or more per state per day. However, that federal mandate was in effect only during 2020 and was limited to employers with fewer than 500 employees.

Until the U.S. puts broad requirements in place forcing companies large and small to provide sick leave, Americans will continue to struggle to access the sick leave they need, according to Shabo.

“Companies have shown themselves unwilling to provide meaningful PSL [paid sick leave] voluntarily. Congress must act to ensure workers have the leave they need,” Schneider adds.

Fortune reached out to the top 20 Fortune 500 companies to ask about their current COVID paid sick leave policies.