Fall is typically the season where the flu and other respiratory diseases flare, increasing the demand on an already burdened healthcare system battling a pandemic. Providers are already scrambling to find adequate testing supplies for COVID-19, and worry that the predicted onset of respiratory symptoms during flu season may increase the backlog. Some Americans are waiting weeks to get the results of their COVID-19 tests and this delay could be worsened by doctors having to test for both viruses.

A study published in The Lancet said a delay of only three days makes it nearly impossible to slow the spread of the coronavirus. People who may be positive with COVID-19 can infect dozens of people while waiting for test results, and those who are negative often have to put their lives on hold until they get clearance to move ahead.

“Every day they wait is another day of quarantine, or if they’re not, it’s another day they could be infecting other people,” said Dr. Keith Jerome, of the University of Washington medical school.

According to The New York Times, some manufacturers have developed combo tests that detect more than one pathogen but these are expensive and rare.

“The flu season is a ticking time bomb,” Amanda Harrington, associate professor and medical director of microbiology at Loyola University Medical Center, told the Times. “We are all waiting and trying to prepare as best we can.”

Medical experts are concerned that since the symptoms of the flu and the coronavirus are similar, a person can have both illnesses at the same time, making it important for an accurate diagnosis so that proper treatment can be administered.

According to The Seattle Times, as the flu season collides with COVID-19, getting the flu vaccine is more important than ever.

“I’m worried about the whole kit and caboodle and how confusing it might be,” said Dr. John Lynch, a board-certified physician and medical director of Harborview’s Infection Control at the University of Washington Medicine. “That’s why getting a flu shot this year is more important than ever—not only to keep you and your family and the community safe from flu, but also to keep people with these other COVID-like illnesses out of doctor’s offices and emergency departments.”

Pharmaceutical companies have increased the production of flu vaccines and healthcare agencies are positioned to make the vaccine more accessible to populations who are most at risk, according to the Seattle Times.