Children receive nasal spray flu vaccine at Xi'an Daxing Hospital in Shaanxi province on Sept 15. [Photo by Ruan Banhui/For chinadaily.com.cn]

"The protection of the nasal spray flu vaccination is more comprehensive, and its effects are longer-lasting and overlapping."

Each shot of live attenuated nasal spray flu vaccine costs about 338 yuan ($50). People can get it at clinics at Xi'an, according to local health authorities.

Autumn is the season in which various kinds of respiratory infections spike. According to the World Health Organization, about 20 to 30 percent of children globally are infected with the flu every year.

The nasal spray vaccine can mitigate children's fears of injections and pain, so the new method is conducive to mass immunity in the future, Luo said.