FluMist, a nasal spray influenza vaccine, received a federal approval Wednesday for the treatment of healthy young children between 2 and 5 years old.

The approval by U.S. Food and Drug Administration (FDA) increases the range of patients in American market that can now be treated with Astrazeneca's Flumist, which previously was limited to healthy children over 5 and adults up to the age of 49.

Manufactured by Maryland-based MedImmune Inc., a wholly owned subsidiary of the Anglo-Swedish drug company AstraZeneca, FluMistcontains a weakened version of live flu virus. It is sprayed into the nasal passages as opposed to being administered by injection.

Jesse Goodman, director of the FDA's Center for Biologics Evaluation and Research said in a press release, "This approval offers parents and health professionals a needle-free option for squeamish toddlers, who may be reluctant to get a traditional influenza shot."

According to the U.S. Centers for Disease Control and Prevention (CDC), Flu season is right around the corner and the best time to get vaccinated is October or November, However, one can still get all children from 6 to 59 months be vaccinated against the flu in December or later.

The researchers also cautioned that FluMist is not approved for people with asthma or children under 5 who have recurrent wheezing because this could get worse after the vaccine.

People who are allergic to the substances in FluMist, such as eggs and egg derivatives, should also not be given the vaccine.

The FDA approved FluMist's younger age limit for children based on three studies that included about 6,400 children aged 6 months to nearly 5 years.

Also, children under 2 years old should not be given FluMist since they are at a higher risk of being admitted to hospital and developing wheezing. The most common adverse events in children aged from 2 to 6 were in the main mild and included runny nose, nasal congestion, and slight fever.