The flu is unpredictable and people should not delay in vaccinating their children, new policy advises.

(HealthDay)—As soon as the updated seasonal flu vaccine becomes available, parents should bring children aged 6 months and older to get vaccinated, according to an updated policy statement from the American Academy of Pediatrics (AAP).

The AAP now recommends that kids be protected against the flu with either the trivalent vaccine, which contains three strains of the virus, or with a new quadrivalent vaccine that offers protection against four strains of flu.

The quadrivalent vaccines for this year's contain the same three strains as the trivalent vaccine, but it may also offer protection from an additional B strain. The AAP has not said that one vaccine is better than the other. Instead, the group said to get either one of these vaccines at the first opportunity.

"Parents should not delay vaccinating their children to obtain a specific vaccine," Dr. Henry Bernstein, a pediatrician and lead author of the flu recommendations, said in an academy news release. "Influenza virus is unpredictable, and what's most important is that people receive the vaccine soon so they will be protected when the virus begins circulating."

The AAP experts said timely vaccination against the flu is particularly important for children who are most vulnerable to the flu, such as those with chronic health issues and those of American Indian or Alaskan Native heritage. In addition, , women who are pregnant or breast-feeding, and anyone who has contact with high-risk children should also be vaccinated as soon as possible.

People who are allergic to eggs can receive the inactivated , which is given in one dose. The AAP said, however, that patients who have had severe reactions should consult an allergist.

For children who are hospitalized with the flu or who have severe , as well as kids with the flu who have , the AAP recommended treatment with the oseltamivir (brand name Tamiflu) or zanamivir (Relenza). Oseltamivir may be used to treat both full-term and premature infants with the flu. Chemoprophylaxis, however, should be used only to treat full-term babies, according to the AAP news release.

The AAP's updated policy statement was published online Sept. 2 in the journal Pediatrics.

More information: The U.S. Centers for Disease Control and Prevention has more about the flu vaccine.

Journal information: Pediatrics