It seems the advertisements to "get your flu shot" start earlier and earlier every year. This year, pharmacies nationwide started carrying the flu shot in early August, according to Jim Cohn, media relations representative for Walgreens.
So if you get a flu shot on August 1, are you protected for the entire flu season? Season typically begins in November and runs through May, according to the Center for Disease Control and Prevention (CDC).
The answer is yes, according to Tom Skinner, senior press officer for the CDC. "A new flu vaccine is manufactured every season. The CDC, along with other organizations, studies virus samples collected from around the world to identify the influenza viruses that are the most likely to cause illness during the upcoming flu season," he explains.
Therefore, as soon as your local pharmacies and doctor's offices start to offer the vaccine, you can get a shot and be protected for the entire flu season. The vaccine remains effective for up to one year.
However, just because the vaccine was available in early August this year doesn't mean the timing will be the same next year. "The timing of the completion of influenza vaccine production varies from year to year and depends upon on a number of factors, including the viruses chosen for inclusion in the vaccine," Skinner says. Basically, in some years, producing the vaccines takes longer.
The protective antibodies in the flu shot declines over time. So if you get your flu shot in August, by the following year, that shot is ineffective for two reasons. First, the antibodies in your body have worn off and are no longer strong enough to protect you. More importantly, the newer flu vaccine will protect against the common viruses for the upcoming year, which may vary from the antibodies that were in last year's flu shot. For example, the 2012-2013 vaccine protects against two flu viruses that are different from those in last season's vaccine.
For maximum protection, the CDC recommends that everyone 6 months and older get annual vaccinations. For people over 65, getting the shot annually is crucial because their age and certain health conditions put them at greater risk for serious flu complications. Seniors should consider getting the higher dose flu shot designed to address the age-related decline of the immune system by triggering the body to produce more antibodies.