New Delhi, July 25: A Chinese vaccine against Japanese encephalitis (JE), imported by the health ministry and administered to nine million children in four states, has struck controversy with 22 children dying after receiving the shots.

Senior health officials spearheading the vaccination campaign have said the deaths have nothing to do with the vaccine, but experts have questioned the process of using an imported vaccine without safety and efficacy studies in India.

As The Telegraph had first reported in December last year, India’s drug regulators had rejected the Chinese-made vaccine three years ago when two Indian drug companies had asked for permission to conduct clinical trials with it.

Scientists have said their concerns over the vaccine have to do with safety issues. “It is a live vaccine, and there is no safety and efficacy data from India,” said a senior virologist at a research centre in India.

The campaign has so far vaccinated nine million children under the age of 15 in Assam, Karnataka, Uttar Pradesh and Bengal to protect them from JE, a potentially lethal viral infection that killed over 1,800 children in India last year.

India had to import the vaccine from a Chinese manufacturer as the production capacity of its own indigenous JE vaccine falls far short of the demand.

Since the immunisation campaign with the Chinese vaccine began earlier this year, health authorities have reported 22 deaths after vaccination ? seven in Assam, two in Karnataka, seven in Uttar Pradesh and six in Bengal.

“This hue and cry is very wrong,” said Shobhan Sarkar, national technical adviser with the health ministry. “We’ve investigated each of the reported deaths and we can with certainty say that they are not in any way linked to the vaccine.”

Health ministry officials said state government teams have also ruled out the vaccine as the cause of the deaths. “I think there are commercial interests trying to kill the programme,” one official said on condition of anonymity.

Since 1988, 200 million children have received the vaccine in China. South Korea and Nepal have also used it. A Global Advisory Committee on Vaccine Safety had last year described the vaccine as showing “excellent safety and efficacy”.

However, the committee had also called for more studies of its safety in special groups such as immunocompromised people, whether the live virus in the vaccine is shed by recipients and the implications of such shedding. The vaccine has also not yet been “prequalified” by the World Health Organisation, a condition for procurement from UN agencies.