Tessa Martyn’s former boss recently asked her if she would like to return to work this autumn. Her answer was no. The job was with a child-care program in a middle-class suburb outside Chicago; it shut down in March 2020. Martyn previously thought that even with her worries about COVID-19, she would return this fall, perhaps in a role that limited her exposure to other people. But with the spread of the Delta variant, she is steering clear of the local school where the program is held. “Right now, with this new variant, the school is the worst place to be,” Martyn told me.

Being around unvaccinated people is extra fraught for Martyn: She lives at her family home and her older brother is on immunosuppressants to prevent his body from rejecting a kidney transplant. (Although he received a COVID-19 vaccine, subsequent tests found that he didn’t develop antibodies.) Of course, “unvaccinated people” currently includes the 50 million or so children in America who are under 12 years old and are ineligible for a vaccine. Because this is also a population in need of in-person care, some child-care workers fear contracting the highly transmissible Delta variant. Kids and adults wearing masks reduces the spread of the coronavirus, and the risk of serious illness from COVID-19 is significantly lower for people who are fully vaccinated. But even inoculated workers like Martyn fear becoming asymptomatic carriers of the virus, and perceive the risk of infection as too high. As a consequence, some of them are opting out of the industry just at the moment when families need them desperately. That’s entirely understandable—but leaves parents of young children with fewer and fewer options for support.

Rasheed Malik, an associate director of research at the Center for American Progress, told me that the contagiousness of Delta and cases of breakthrough infections are prompting many child-care providers to reconsider their line of work. “The Delta variant has really changed the calculus for many people. They saw this coming fall as the light at the end of the tunnel. Now it’s looking like last fall,” Malik said. “It’s a lot of uncertainty piled on uncertainty piled on risk for child-care workers right now.”

A child-care shortage existed before the coronavirus pandemic, but the events of 2020 exacerbated it. In some states, day-care employees were not designated essential workers during last year’s shutdowns, and their workplaces had to close permanently. One study found that in the United States, two-thirds of child-care centers shut down in April 2020. Zachary Parolin, a co-author of the paper and an assistant professor at Bocconi University, in Italy, told me that 29 percent of all centers nationally remained closed or operating at half-capacity as of this June. He anticipated that this figure would increase in the coming months as the Delta variant spreads.

About 35 percent of child-care workers lost their job early in the pandemic, and only about two-thirds have returned to work, according to Malik. Many of these workers—including employees of day-care programs, part-time babysitters, and full-time nannies—were already hesitant to resume their job and expose themselves to the coronavirus. Now Delta has heightened that feeling. Prior to the pandemic, Sittercity.com, an online platform that matches families and babysitters, had an average of one sitter for every five families seeking care. During the pandemic, that ratio got worse, dropping to one sitter for every 10 families. By the end of July, the ratio was 1 to 14, Zenobia Moochhala, the site’s CEO, told me.

Exhausted parents and a shortage of child-care workers mean that the latter can pick and choose their jobs, giving them uncommon leverage in a typically low-paying industry. In May 2020, day-care workers earned a median wage of less than $12 an hour. Annual turnover in some child-care jobs can be as high as 30 percent, according to the Health and Human Services Administration for Children and Families.

Now these workers are closely considering household safety and potential exposure to unvaccinated children when deciding if they’ll take a job. Many child-care providers work part-time without benefits such as health insurance, leaving the burden of ensuring workplace safety on the individuals themselves. Some nannies are also selective about what professions the parents employing them have—medical-care providers and other public-facing workers might have a harder time finding care, Jada Rashawn, a consultant for Sittercity.com, told me.

Moochhala said that the number of conversations between parents and sitters about vaccine status has doubled since April, according to company data. And almost 40 percent of surveyed sitters on the platform said that Delta was prompting them to either work only for one family—instead of three or four concurrently—or refuse to sit for families with unvaccinated members (other than children under 12), Moochhala said.

For Brittney Kirton, the spread of Delta and the end of a nannying contract prompted her to return in June to working as a newborn specialist, providing support for a couple who just had a baby. In large part, that was because she expected the family to stay close to home for the first one to three months after the baby was born. “As far as COVID is concerned, this could potentially be the best route to limit outside risks,” Kirton told me.

Sometimes, though, no personal cost-benefit analysis makes child care a worthwhile job when the stakes of Delta are so high. Martyn has declined babysitting jobs and even a dog-sitting gig for someone who teaches young children. Although Martyn might return to child care in the future, she’s not considering it while the variant persists. Workers like her can’t be blamed for choosing not to expose themselves to unvaccinated children, just as parents aren’t responsible for not being able to get their young kids vaccinated. But not for the first time in the pandemic, all parties are ending up on their own.