The available vaccines from Pfizer and Moderna must be stored between 36 and 46 degrees Fahrenheit and -13 and 5 degrees Fahrenheit respectively. Once the vaccine thaws, it must be administered within six hours—otherwise, it’s no longer viable. To avoid having to discard valuable doses of vaccine, some pharmacies, like CVS and Walgreens, are compiling waitlists of eligible employees to vaccinate, The Wall Street Journal reports. Retailers are trying to navigate each state’s eligibility requirements to determine who can earn a spot on the waitlist. While retail workers are currently eligible for the vaccine in some states, they’re not in others. Of course, some employees may be eligible otherwise due to their age or preexisting conditions. To see if the Walgreens in your state has the COVID vaccine, check out If You Live in These States, You Can Now Get Vaccinated at Walgreens. Pharmacists at CVS are also keeping a list of qualified patients in each state to determine who will receive leftover shots, senior vice president of CVS Health Chris Cox told CNBC.ae0fcc31ae342fd3a1346ebb1f342fcb A Walmart spokeswoman told The Wall Street Journal they also plan to offer extra doses at risk of being thrown out to shoppers who qualify under state guidelines. To see if your local CVS is offering the COVID vaccine, check out If You Live in These States, You Can Now Get Vaccinated at CVS. According to The Wall Street Journal, “Companies say leftover doses, in many cases, can also go to workers who wouldn’t otherwise qualify, such as cashiers.” While T.J. Crawford, a spokesperson for CVS, told Fortune that surplus doses are “minimal,” he added: “In the rare instances where we do have expiring doses, we reach out to employees and customers who qualify. If we’re not able to locate anyone from eligible populations, we’ll make sure no dose goes to waste by vaccinating on-site employees.” According to Fortune, Walmart has also said if no one eligible is available to use the excess vaccine at the end of the day, they’ll move on to lower-priority groups where allowed. This is in line with the guidelines from the Centers for Disease Control and Prevention (CDC), which “supports optimizing the use of all COVID-19 vaccine.” The agency’s Advisory Committee on Immunization Practices says sites should be “expanding vaccine availability to broader population groups when vaccine supply at a certain location is in danger of being unused. Pharmacies should use this guidance when making plans to ensure no dose is wasted.” And for more up-to-date COVID news delivered straight to your inbox, sign up for our daily newsletter. Doctors don’t recommend milling about your local vaccination site or pharmacy to see if they have an extra dose for you, since this could potentially lead to overcrowding. “I worry about the potential for infection,” Leana Wen, MD, an emergency physician and public health professor at George Washington University, told PBS News Hour. “How tragic would it be if you were to contract coronavirus… while trying to get a dose of the vaccine?” But with the goal of getting as many people vaccinated as possible and wasting as little of the vaccine as possible, websites like vaxstandby.com and hidrb.com have started waitlists to alert the public where excess doses may be available. Registered providers alert these sites how much vaccine they have leftover, the time remaining on their viability, and how many people they want to notify. Then, VaxStandby sends a text message to people in the area who’ve signed up to receive vaccine alerts, based on zip code, NBC Boston reports. And to see if your local Walmart is administering the COVID vaccine, check out If You Live in These States, You Can Now Get Vaccinated at Walmart.