If you test positive for COVID-19 this week, odds are, you can blame the delta variant.The strain is so contagious, it’s now causing 99% of new cases in the U.S. But since COVID-19 is always mutating, a more dangerous variant may already be out there. Inside Northeastern University’s Life Sciences Testing Center in Burlington, a delivery cart with hundreds of COVID-19 tests from the Boston campus arrives every few hours.Jared Auclair, the Director of Biotechnology and Bioinformatics, at Northeastern University said, “Since school started, we’ve been averaging about 5,500 tests per day.”Auclair directs the lab and designed the process for analyzing each swab from students and staff.”We have an opportunity to understand how the virus travels through our fairly isolated community in a very highly vaccinated population,” Auclair said.According to Northeastern, 98% of students and 95% of faculty are fully vaccinated. But vaccinated or not, anyone who spends more than one day per week on campus must agree to weekly testing.White boxes contain the routine tests. A blue box carries swabs from people who say they’re feeling sick.”And these machines tell us if you’re a positive or negative sample. Once we know that, then we take all those positive samples and we store them,” Auclair said.When we visited the lab, 16 people tested positive, so that means 16 samples move to a machine where researchers can identify the variant within four to six hours.Auclair says, the answer is important to his lab, but not essential to patients.”Clinically we treat them the same. There’s no specialized treatment for any given variant, right? So it doesn’t really make any difference what the variant is, the course of treatment is the same,” he said. The lab’s current targets — delta, alpha, beta and gamma.The World Health Organization lists them as variants of concern because research shows they may be more contagious, less responsive to treatments or cause more severe symptoms.But the staff here is also on alert for the next new threat.”Every time a variant enters somebody’s body, it’s going to mutate. If you’re vaccinated, it’s going to potentially mutate around that vaccine, right? And we need to really make sure we’re tracking that so that if something’s going to mutate around the vaccine we can react,” Auclair said.If the sample on the swab doesn’t fit the profile for one of the variants already circulating, the lab sets it aside for a more detailed analysis that can take four to six days.”We do expect other variants to travel here — mu and whatever other Greek letters come after mu. As the number o people who are vaccinated increases the number of variants will decrease, but that will never hit zero,” Auclair said.The search for what’s next continues, one swab at a time.”If there’s a new variant that pops up, we’ll be one of the first people to know,” Auclair said.The Northeastern lab routinely shares its results — and sometimes samples — with the state.The data also can be used to develop more effective vaccines and even booster shots.