Flu vaccines cause antibodies that provide protection against infection with the viruses that are in the vaccine. The seasonal flu vaccine protects against the influenza viruses that research indicates will be most common during the upcoming season. Traditional flu vaccines (called “trivalent” vaccines) are made to protect against three flu viruses; an influenza A (H1N1) virus, an influenza A (H3N2) virus, and an influenza B virus. There are also flu vaccines made to protect against four flu viruses (called “quadrivalent” vaccines). These vaccines protect against the same viruses as the trivalent vaccine and an additional B virus.
When should I get vaccinated?
Everyone 6 months of age and older should get a flu vaccine every season. You may start to have a Flu vaccine soon after vaccine becomes available. If flu viruses are circulating, vaccination should continue to be offered throughout the flu season, even in January or later. Since it takes about two weeks after vaccination for antibodies to develop in the body, it is best that people get vaccinated early so they are protected before influenza begins spreading in their community.
Why do I need a flu vaccine every year?
There are two reason why a flu vaccine is needed every season. First, the body’s immune response from vaccination declines over time, so an annual vaccine is needed for optimal protection. 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. Everyone 6 months and older should get vaccinated annually for the best protection.
How effective is a flu vaccine?
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, effectiveness of the vaccine 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. The vaccine can provide some protection (called cross-protection) against different but related influenza viruses.
The flue vaccine provide the following benefits:
- Flu vaccination can keep you from getting sick with flu.
- Flu vaccination can reduce the risk of flu-associated hospitalization among children and older adults.
- Flu vaccination is an important preventive tool for people with chronic health conditions.
- Vaccination helps protect women during and after pregnancy. Getting vaccinated can also protect a baby after birth from flu. (Mom passes antibodies onto the developing baby during her pregnancy.)
- Flu vaccination lessen the effect when you get ill.
- Having a vaccination doesn’t only protect yourself it also protects people around you, including those who are more vulnerable to serious flu illness.