“I was going to work for several months and then take off later in the race. It just didn’t end up happening that way,” she said. “It’s hard to keep a job or find a job when you’re running against a Democratic incumbent.”

She is doing her best to keep her campaign going while she recovers from pneumonia, staying present on social media until she feels healthy enough to become more active.

“We structured our campaign to where it continues to roll even when I’m sick,” Ms. Bush said. “We will be able to make it day by day. But once I’m back, I’m back.”

Ms. López, who was once homeless herself, left her job at a nonprofit group that builds housing for the homeless in order to run.

She mulled the decision for months, and the prospect of losing her health insurance and her income was one reason it took so long to make up her mind. She had some savings, enabling her to take the leap, but she said that money would run out soon.

Right now, she said, her focus is on helping people in her Bronx district, where many people live in poverty and which has been hit particularly hard by the coronavirus. As her entire campaign operation moved online, she began using her network of volunteers not only to phone and text bank but also to try to get resources and supplies to those who needed them.

She’s currently staying isolated, since she knows her health is directly related to the well-being of her campaign.