Two Doses of H1N1 Vaccine Recommended for Kids Under 10

The CDC’s Advisory Committee on Immunization Practices recommends that children aged 6 months to 9 years receive 2 doses of influenza A (H1N1) 2009 monovalent vaccine; the doses should be given about 4 weeks apart. Persons aged 10 years or older require only 1 dose.

The approved age groups for each vaccine are listed in a table in the CDC report in MMWR. They can be summarized as follows:
•Sanofi Pasteur inactivated vaccine is recommended for persons older than 6 months (1 dose, IM, except for children younger than 10 years who should receive 2 doses).
•Novartis inactivated vaccine, for persons age 4 years and older (1 dose, IM, except for children younger than 10 years who should receive 2 doses).
•CSL inactivated vaccine, for persons who are at least 18 years old (1 dose, IM).
•MedImmune live attenuated influenza vaccine (LAIV), for persons age 2 to 49 years (1 dose, intranasally, except for children younger than 10 years who should receive 2 doses).

In addition to children younger than 2 years and adults older than 49 years, the LAIV should not be given to pregnant women, persons with underlying medical conditions that confer a higher risk of  influenza complications, or children younger than 5 years who have had 1 or more episodes of wheezing in the past year.

All the vaccines contain egg protein, and the report in MMWR provides details on those that contain mercury.

Preliminary data show that the immunogenicity and safety of these vaccines are similar to those of seasonal influenza vaccines. The most common adverse effects were local discomfort (eg, injection site tenderness or pain) and mild systemic symptoms (eg, headache, malaise, or myalgia).