Yes, You Should Still Get Vaccinated Even After Having Influenza This Year
Annual influenza vaccination is recommended for all persons aged ≥6 months regardless of prior influenza infection during the same season, because natural infection with one influenza strain does not provide protection against other circulating strains that may be present during the same flu season. 1
Why Vaccination Is Still Necessary After Infection
Multiple strains circulate simultaneously: Each flu season typically involves multiple influenza virus types and subtypes (A(H1N1)pdm09, A(H3N2), B/Victoria, and B/Yamagata lineage) circulating at the same time. 2
Infection provides only strain-specific immunity: Having influenza A infection means you were infected with only one specific strain, leaving you vulnerable to other strains circulating during the same season. 1
The vaccine protects against multiple strains: Current influenza vaccines are quadrivalent, designed to protect against four different influenza viruses simultaneously. 2, 3
When to Get Vaccinated After Infection
You can receive the influenza vaccine as soon as you have clinically recovered from your acute illness, with no required waiting period after influenza infection. 1
Specific timing guidelines:
Wait until symptoms resolve: The only requirement is that you should not be vaccinated while experiencing moderate to severe acute febrile illness. 1
No mandatory waiting period: Once you are no longer acutely ill, vaccination can proceed immediately. 1
Optimal season timing: While you should get vaccinated as soon as you recover, the general recommendation is to vaccinate by the end of October for optimal protection throughout the season. 4
Additional Important Considerations
Vaccine effectiveness despite prior infection:
Protection develops in 2 weeks: It takes approximately 2 weeks after vaccination for protective antibodies to develop in healthy adults. 1
Continued benefit throughout season: Vaccination should continue to be offered throughout the influenza season as long as vaccine supplies are available, even after influenza activity has been documented in the community. 4
Prevention of serious outcomes: Even when vaccine effectiveness against specific strains is reduced, vaccination can still prevent serious outcomes including hospitalization, ICU admission, and death. 2
Special populations requiring particular attention:
High-risk individuals should not delay: For persons at increased risk for influenza complications (those ≥65 years, with chronic medical conditions, pregnant women, young children), vaccination should not be delayed once clinically recovered. 1, 4
Children may need two doses: Children aged 6 months through 8 years receiving influenza vaccine for the first time require 2 doses administered at least 4 weeks apart, regardless of prior influenza infection. 1
Common Pitfalls to Avoid
Don't assume natural infection provides complete protection: This is the most critical misconception—having had the flu once does not protect you from other circulating strains. 1
Don't delay vaccination waiting to feel "completely normal": As long as acute symptoms have resolved and you are no longer febrile, vaccination can proceed. 1
Don't skip vaccination late in the season: Even if it's January or February and you've already had influenza, vaccination is still recommended as influenza activity often peaks in February and can continue through May. 4
Don't confuse antiviral medication timing with vaccination timing: If you used antiviral medications, this only affects live attenuated vaccine (nasal spray) within 48 hours; inactivated vaccines can still be administered. 1