Students from migrant worker families and those from overseas at Beijing's primary and high schools will be able to get free inoculations for the flu along with local students between Oct 20 and Nov 30.

Pang Xinghuo, vice-director of the Beijing Center for Disease Control and Prevention, said the vaccine that will be used this year will prevent seasonal flu strains seen in previous years as well as the H1N1 virus.

People wanting the jab, which will be available at 491 locations, will need to sign an agreement asserting they are healthy and able to accept it. The declaration forms will be available in English for foreign students. "Students will receive the free inoculation after their parents sign the agreement," said Pang.

However, some foreign students are reluctant to have the injections. Andrew Andrea Dal Mas, an Italian student at No 55 Middle School, said he has never been vaccinated against the flu.

"I will have to consult my parents before receiving the inoculation and I don't think they will agree to let me be vaccinated," he said. "If it is really necessary, I will receive it when I go back to Italy during the summer vacation."

Pang said that the inoculations will be available for several days after the Nov 30 cut-off, if necessary, to meet demand and she said each clinic will be able to set its own deadline.

"We suggest citizens get inoculated as early as possible," she said. "Getting the vaccination too late will not help with disease prevention."

The free vaccinations are only available for students and senior citizens aged 60 and older. Others wanting the injections will be able to get them for between 50 and 80 yuan.

Peng said the vaccines being used this year were produced by 11 medical factories. About 2 million people are likely to get the free inoculations this year.

Statistics from the Beijing Health Bureau show that more than 5 million citizens have received the free seasonal flu vaccine since 2007.

The number of people developing the flu each year has been falling as a result.

While more than 1 million people caught the flu between October 2006 and March 2007, fewer than 500,000 got the illness during the flu season in the following years.

Wu Hao, director of the infectious diseases department at You'an Hospital, said children younger than 5, senior citizens with diminished immune systems and women who plan to have a baby during the flu season should get the vaccine.

"Babies who are more than 6 months old can have the inoculation," he said. "Clinical tests show that about 70 to 95 percent of people will not be infected after taking the vaccine." He said the vaccine activates the body's immune system about two weeks after people get the jab. The effects last for about a year. "The virus changes quickly, so we need to develop a new inoculation each year," he added.

The city's healthcare hot line at 12320 will be available for questions about the vaccine and people can also use the number to log complaints.