You’ve just left the pharmacy—or school gym, or baseball stadium, or some other COVID-19 vaccine distribution facility—with a vaccination card in your hand, an adhesive bandage on your arm, and maybe a few questions about what happens next. From how to handle side effects to when to mask up, here are five helpful pieces of post-vaccine advice.

1. Don’t panic about COVID-19 vaccine side effects.

If you’re wracked with flu-like symptoms and anxious about your body’s unpleasant reaction to the COVID-19 vaccine, hearing a loved one repeatedly tell you “That means it’s working!” might not be the sympathy you’re looking for. But it’s true. Chills, muscle aches, fever, fatigue, and other unsavory side effects are all signs that your immune system is mounting a resistance to the virus. They’re completely normal and no cause for panic—even if you’re feeling way worse after your second dose than you did after the first.

“With the two-dose vaccines, the first dose typically primes the immune response to the vaccine, creating antibodies,” Dr. Brandon Dionne, a clinical pharmacist in infectious diseases at Brigham and Women’s Hospital, and assistant clinical professor in Northeastern University’s department of pharmacy and health systems sciences, tells Mental Floss. Basically, the first dose contains instructions telling your cells to make a harmless version of the virus’s spike protein—the spiky compound on the surface of the pathogen—and then produce antibodies that will know how to fight the real thing.

“When you receive the second dose, you already have some level of protection from the antibodies to the spike protein target of the vaccine,” Dionne explains. “This allows the immune system to respond more quickly and strongly to the vaccine, which can lead to more inflammation and potentially more severe side effects. Although this can be uncomfortable, it’s a sign that your immune system is working to provide protection against the virus.”

On the flip side, if you feel totally fine after you get the vaccine, you shouldn’t worry that it isn’t working. “You can still have an adequate immune response even if you didn’t experience side effects,” Dionne says.

2. Do rest up, stay hydrated, and take medicine if necessary.

Just because your immune system knows what it’s doing doesn’t mean you can’t help. Sleep is an important component to immune system functioning, so make sure you get enough rest after your shot. Drinking plenty of fluids, just like you would with a cold, can also help mitigate discomfort from fever and other side effects. Some people have warned against preempting side effects by taking over-the-counter medications like Advil (ibuprofen) or Tylenol (acetaminophen) on the grounds that they might interfere with your immune system and make the vaccine less effective. But treating your vaccine-related issues after the shot should be fine.

“There is some retrospective data that taking NSAIDs or acetaminophen can reduce response to other vaccines, and laboratory data with mice showed that NSAIDs reduced antibody levels after infection with SARS-CoV-2,” Dionne says. “While the evidence is not conclusive, I think it makes sense to avoid these medications prior to your vaccine unless you are already taking these regularly … If you experience more severe side effects from the vaccine, like fever or headache, it is reasonable to take either NSAIDs or acetaminophen as soon as they start.”

If you don’t start feeling better after a few days, then you should go ahead and consult your doctor.

3. Do use your vaccine arm.

Muscle soreness at the injection site is an especially common vaccine side effect, and your instinct might be to let your arm hang limp as often as possible. The CDC actually advises the exact opposite: “Use or exercise your arm.” In addition to not letting it get too stiff, you can also mitigate pain by applying “a clean, cool, wet washcloth over the area.”

4. Do keep your vaccination card—but don’t post it on social media.

Proof of vaccination is starting to be required at certain travel destinations and venues, and a number of apps have been developed to digitize that process. But you should definitely still hang onto your paper vaccination card for now.

What you shouldn’t do is share a photo of it on social media. Not only does that make it easier for scammers to forge their own cards, but it also makes you more vulnerable to identity theft—even basic details like your birthday can help thieves guess your social security number. (Also, don't laminate it. You may need to update your card later with proof of a booster shot or other information.)

5. Don’t stop wearing your mask in public.

Two weeks after getting your second shot of the Pfizer-BioNTech or Moderna vaccine, you can consider yourself “fully vaccinated,” which does open up a few doors for your social life. According to the CDC, fully vaccinated folks can hang out inside with other fully vaccinated people without wearing masks or staying 6 feet apart. Fully vaccinated people can do the same with members of one other household of unvaccinated people, unless any of those people are at an “increased risk for severe illness from COVID-19.”

Larger get-togethers are still on the “no” list for everyone, fully vaccinated or not. If you do find yourself indoors with people from multiple households, mask up. And you should absolutely keep wearing your mask and social distancing in all public places.