A mass psychogenic reaction was to blame for the hospitalization of 46 children after receiving Hepatitis B vaccinations Thursday in south China's Guangdong Province, local authorities said Friday.

The children, among 84 who received the shots at a primary school in Huilai County in Jieyang City, claimed that they had developed symptoms of a reaction, including feeling nauseated and dizziness, Wu Junqiu, head of the county center for disease control and prevention, told a press briefing Friday.

The number hospitalized was 44 by 6:00 PM Thursday, but it rose to 46 after two more students went to hospital later, Wu said.

The symptoms in most students disappeared after placebo treatments such as intravenous injections of glucose, Wu said.

All the students had been discharged from hospital by 4:20 p.m. Friday.

Initial investigations by the provincial, municipal and county heath authorities showed the illness was not caused by the shots, Wu said.

The HB vaccine used came from a batch of 110,000 doses, of which, more than 90,000 doses had been administered, but no other abnormal reactions had been reported, Wu said.

The vaccine, which had a use-by date of Sept. 1, 2010, was produced by a company based in Shenzhen city of Guangdong.

(Xinhua News Agency April 24, 2010)