The US Center for Disease Control (CDC) has issued a recall for some 800,000 doses of A/H1N1 flu vaccine, local media reported Tuesday.

According to New York local TV channel NY1, these doses of vaccine made by Sanofi Pasteur "may not be effective enough to protect against the virus."

The affected vaccines are pre-filled syringes for children aged six months to almost three years old.

The US CDC reportedly said the doses were sent all over the country, and it is reaching out to providers who received to notify them not to use any of the remaining supplies.

Health officials were cited as saying that children who already received the dose likely will not need to be re-vaccinated.

New York city health officials were cited as saying they are still waiting to hear if any of the recalled doses were sent to the five boroughs of the city.

(Xinhua News Agency December 16, 2009)