Just after a spring break trip to Vail, Colorado, Shawn Cunningham’s stomach started cramping. She ran a fever, her chest felt tight, and she lost her appetite and her senses of taste and smell. Her asthma and allergy doctor in San Antonio found a clinic nearby that would test her for COVID-19. She had it.

After a few weeks under home quarantine, Cunningham, 49, started feeling better and looked forward to leaving the house. A self-described extrovert, she hoped to buy groceries for the elderly who feared going outside and get back to work as a real estate broker.

“I was developing this attitude of invincibility,” Cunningham said. “My mind-set was, ‘I can’t give it and I can’t get it.’” Then a nurse at Metro Health told her she might be at risk of catching a secondary infection with a weakened immune system, and she changed her mind about going out.

Cunningham is one of at least 7,300 Texans who have recovered from the coronavirus. While that’s good news for many reasons—including the fact that survivors may be able to help others with COVID-19 by donating plasma—it’s not necessarily the liberating factor people have hoped for. The debilitating effects of the disease can linger for weeks, and so much about COVID-19 remains unknown, including whether or not those who have recovered can get it again.

Generally, the body creates antibodies to help fight off viruses and prevent future infection, but the World Health Organization said Friday there is no evidence that those who have tested positive and recovered have immunity to COVID-19. For SARS, a cousin to the current coronavirus, researchers found that the antibodies people developed prevented reinfection for about three years. But because COVID-19 is so new, it’s not yet clear whether those who recover are immune, and, if they are, for how long.

“Nobody is sure whether someone with antibodies is fully protected against having the disease or being exposed again,” said Dr. Mike Ryan, executive director of WHO Health Emergencies Programme.

Further, it’s not yet clear what, if any, long-term effects the disease may have on those who have been infected. Early small-scale studies show that some people sustained damage to their lungs, heart, liver, kidneys, and blood.

Given the uncertainty, Cunningham decided to limit the amount of time she spends outside the house. She can’t wait to see her sisters again and kiss her one-year-old nephew, but she knows it’s for the best that she stays away. “The last thing I want to do is get something else that lands me in bed again,” she said. “Being out scares me a bit because people are so lax.”

Cunningham’s been trying to get a second test to confirm that the virus is out of her system, but tests are still in short supply. Once she gets a negative result, she plans to donate plasma, as the FDA is encouraging people who have recovered from the coronavirus to do. The theory is that plasma that contains antibodies to the disease can be given to an infected person to help jump-start their immune system. But while the method was effectively employed to treat outbreaks including the Spanish flu and Ebola, the FDA notes that it hasn’t proved effective yet in treating COVID-19.

Adding to the list of unknowns for survivors is the question of how long people with the virus remain contagious. The CDC says people with COVID-19 can end home isolation one week after they first experience symptoms as long as their symptoms have improved and they’ve been fever-free for at least three days. But after more than four weeks in the hospital, one Midlothian man, Stephen Donelson, is still testing positive for COVID-19.

Donelson, 58, and his wife Terri have no idea where he picked up the coronavirus. The couple hadn’t left the house in nearly two weeks when Stephen was hospitalized. He had a runny nose for a few days, but that was his only prior sign of sickness. He went to bed one night and a few hours later Terri found him blue and barely breathing. An ambulance rushed him to the hospital where he was sedated and put on a ventilator for seventeen days.

“That’s what really is scary,” Terri said. “You’ve got people out there who are fourteen days asymptomatic post-COVID and they potentially could still be infectious.”

Though he’s awake now and able to talk, Stephen is essentially paralyzed from the neck down because his muscles have atrophied from lack of use. Terri hasn’t left the house much at all since he’s been hospitalized. She doesn’t want to risk bringing anything home with her. When the day comes that Stephen is released from the hospital, she said, they won’t be taking any risks.

“We will be extraordinarily cautious,” Terri said. “I say that and I think back 28 days ago and we were extraordinarily cautious then.”

Even after the virus is out of someone’s system, recovery can drag on for weeks or months. Under sedation, machines pumped Chris Hernandez’s blood, fed him, and breathed for him for sixteen days while he battled the coronavirus. When he woke up, the formerly healthy 43-year-old was exhausted after taking just a few steps with the help of a walker. Now that he’s back home after six weeks in the hospital, he’s in no hurry to leave.

“I’d rather be safe than sorry,” said Hernandez, a lieutenant in the Patton Village Police Department who contracted COVID-19 in early March. “It’s a monster. I keep telling people that. Do what they ask you to do because that thing don’t play. It will sneak up on you and catch you.”

Those with relatively mild cases are hesitant to reenter the world unprotected as well. Amie Robinson, 51, an attorney for the Texas Commission on Environmental Quality in Austin, tested positive for COVID-19 at the end of March. She treated her symptoms with Tylenol, and they went away after about five days.

Though it’s been more than two weeks since she experienced any symptoms, Robinson and her boyfriend are scared to leave the house. They wear protective equipment to take out the trash and check the mail.

“I am going to wait until a month,” Robinson said, “Then I will let the paranoia go, but will still be masked and gloved like everyone else.”