As long as flu viruses are circulating, vaccination should continue throughout the flu season.(up till end of season)
Centre for Disease control and prevention (CDC) recommends vaccination (flu shots) to begin soon after vaccine becomes available, if possible.
However, as long as flu viruses are circulating, vaccination should continue to be offered throughout the flu season (winter)
While seasonal influenza outbreaks can happen as early as May, during most seasons influenza activity peaks in June or later.
Since it takes about two weeks after vaccination for antibodies to develop in the body that protect against influenza virus infection, it is best that people get vaccinated so
they are protected before influenza begins spreading in their community. Flu vaccine is produced by private manufacturers, and the timing of availability depends on when production is completed.
Why do I need a flu vaccine every year?
A flu vaccine is needed every season for two reasons.
1. First, the body’s immune response from vaccination declines over time, so an annual vaccine is needed for optimal protection.
2. Second, because flu viruses are constantly changing, the formulation of the flu vaccine is reviewed each year and sometimes updated to keep up with changing flu viruses. For the best protection, everyone 6 months and older should get vaccinated annually.
Can I get seasonal flu even though I got a flu vaccine this year?
Yes. There is still a possibility you could get the flu even if you got vaccinated. The ability of flu vaccine to protect a person depends on various factors, including the age and health status of the person being vaccinated, and also the similarity or “match” between the viruses used to make the vaccine and those circulating in the community. If the viruses in the vaccine and the influenza viruses circulating in the community are closely matched, vaccine effectiveness is higher. If they are not closely matched, vaccine effectiveness can be reduced. However, it’s important to remember that even when the viruses are not closely matched, the vaccine can still protect many people and prevent flu-related complications. Such protection is possible because antibodies made in response to the vaccine can provide some protection (called cross-protection) against different but related influenza viruses.
Vaccine Side Effects (What to Expect)
Can the flu vaccine give me the flu?
No, a flu vaccine cannot cause flu illness. Flu vaccines that are administered with a needle are currently made in two ways: the vaccine is made either with a) flu vaccine viruses that have been ‘inactivated’ and are therefore not infectious, or b) with no flu vaccine viruses at all (which is the case for recombinant influenza vaccine). The nasal spray flu vaccine does contain live viruses. However, the viruses are attenuated (weakened), and therefore cannot cause flu illness. The weakened viruses are cold-adapted, which means they are designed to only cause infection at the cooler temperatures found within the nose. The viruses cannot infect the lungs or other areas where warmer temperatures exist.
While a flu vaccine cannot give you flu illness, there are different side effects that may be associated with getting a flu shot or a nasal spray flu vaccine. These side effects are mild and short-lasting, especially when compared to symptoms of bad case of flu.
The flu shot: The viruses in the flu shot are killed (inactivated), so you cannot get the flu from a flu shot. Some minor side effects that may occur are:
The nasal spray: The viruses in the nasal spray vaccine are weakened and do not cause severe symptoms often associated with influenza illness. In children, side effects from the nasal spray may include:
In adults, side effects from the nasal spray vaccine may include:
Where can I get a flu vaccine?
Flu vaccines are offered in many locations as well as by many employers, and even in some schools.
Reminder: Vaccination à domicile or at work