Can I get a flu shot if I have a cold?

As winter arrives and vaccination centers fill up, many people experience early symptoms of colds or flu. A common question arises: should one get the flu vaccine now, or wait until they recover? According to guidelines from the World Health Organization (OMS), the Center for Disease Control (CDC), and Fiocruz Foundation, mild colds without fever generally do not prevent vaccination. However, cases with fever or signs of infection may require postponing the vaccine until recovery. Eliane Messias, a pharmacist at Rede Drogal, advises seeking medical evaluation for any feverish conditions, as mild colds typically do not impede vaccination.

The Ministry of Health recommends avoiding the influenza vaccine during any febrile illness, including flu, COVID-19, or other diseases, to prevent confusion between illness symptoms and potential vaccine reactions. Additionally, when the body is fighting an active infection, its immune system is occupied, potentially making the vaccine response less effective. Vaccination is generally permissible if fever has subsided for at least 48 hours without severe symptoms. Vaccines are well-tolerated, with common side effects being local reactions like pain, swelling, and redness, along with mild fever or muscle discomfort, which usually resolve quickly. It's important to note that the vaccine contains inactivated virus particles and does not cause abrupt adverse reactions; it aims to build resistance. Any coincidental illness symptoms appearing after vaccination are unlikely to be related to the vaccine itself. For those recovering, the practical advice is to wait until fever has completely disappeared for at least 48 hours before getting vaccinated, though mild residual symptoms like fatigue or a slight runny nose usually do not pose an issue. Vitamin C, while important for the immune system, lacks robust scientific evidence for preventing colds and flu but may modestly reduce symptom duration. It does not replace the vaccine. Vaccination takes about two weeks to generate protection, and with July, a peak month for virus circulation in Brazil, approaching, individuals without fever are encouraged not to delay.