How long (one season or more) will immunity be effective from the H1N1 vaccine? Will this be an annual vaccine like the seasonal flu?
Influenza (flu) viruses change from year to year. You are unlikely to get infected with the same exact strain of influenza (flu) more than once. Most people with flu-like illness since spring 2009 don't know whether they were infected with 2009 H1N1 or another flu virus strain. If you think you had 2009 H1N1 infection, ask your doctor if you should be vaccinated. The only sure way to diagnose 2009 H1N1 infection is with real-time reverse transcription-polymerase chain reaction (RT-PCR).
Even if you had a confirmed case of 2009 H1N1 flu, you can still get infected with other flu strains. You should make sure you get the seasonal flu vaccine. If you had a flu-like illness since spring 2009 that wasn't diagnosed as 2009 H1N1 flu by RT-PCR, get the H1N1 and seasonal flu vaccines.
Also, a vaccine made against flu viruses circulating last year may not protect against the newer viruses. That is why the influenza vaccine is updated every year to include current viruses.
Last Reviewed: 09/30/2009
Related Questions:
- I am allergic to eggs. Can I receive a flu shot even though I am allergic to eggs?
- Will the new H1N1 vaccine be safe, even for children? Are you testing it?
- What chronic health conditions would be considered priority for the vaccination when it becomes available? Heart Murmur? Hypothyroidism?
- If I was vaccinated for swine flu in the 1970's, do I need to get a 2009 H1N1 (swine flu) shot?
- I have a serious lung disease. Will the pneumonia vaccine protect me from the flu?








