CDC's return rule
You can go back to normal activities, including work and school, when for at least 24 hours both are true:[2]
- your symptoms are getting better overall, and
- you have not had a fever, without using fever-reducing medicine.
For the next 5 days, take added precautions when you are around other people: cleaner air, good hand and cough hygiene, a well-fitted mask, distance, or testing.[2]
Fever-reducing medicine such as acetaminophen or ibuprofen can hide a fever, so the 24 hours count only when you have not taken it. More on symptom relief.
School and childcare
CDC uses the same rule for students and school staff: no fever for 24 hours without medicine, and symptoms improving for 24 hours.[3] State and local health departments may have extra rules, and schools are told to follow them too.[3] Daycare and childcare programs may have their own policies, so check before sending a child back.
Healthcare workers
The rule is stricter for people who work in healthcare. CDC's infection control guidance keeps them off work until at least 3 days have passed since symptoms started, they have been fever-free for 24 hours without medicine, symptoms are improving, and they feel well enough. They then wear a mask at work through the end of day 7.[4] Your employer's occupational health team has the final word.
Do antivirals make you less contagious?
What is known:
- In a large trial, a single dose of baloxavir lowered the amount of virus a day after starting more than oseltamivir or placebo did.[7]
- In a 2025 household trial, people treated with baloxavir within 48 hours passed lab-confirmed flu to household members less often: 9.5% versus 13.4% with placebo by day 5. The difference in household members who actually got sick was smaller and could have been chance.[8]
- The same trial notes that studies of oseltamivir and related drugs have not shown enough evidence that they prevent spread to contacts.[8]
What is not known: whether taking any antiviral means you can safely return sooner. CDC's return rule does not change if you take one.[2] You may see a claim that Tamiflu makes you contagious for one day less. FluHub could not trace that number to a primary study, so we do not repeat it as fact.