LUCKNOW, India - India's government sent thousands of ineffective vaccines to a northern Indian state, halting a planned immunization drive against a deadly outbreak of Japanese encephalitis that has killed more than 200 children since June, officials said Wednesday.
The mistake — compounding delays in starting the immunizations — raises chances that hundreds more children could die of the disease this year, health officials warned.
North India's impoverished Uttar Pradesh state suffers from recurring annual outbreaks of the mosquito-borne disease, which causes high fevers and vomiting — and sometimes comas and death. It is particularly deadly among children.
Japanese encephalitis can be prevented by a vaccine, but stocks sent by the federal government to the state showed in testing that they were "unfit for human use," state Health Minister Anant Kumar Mishra told The Associated Press in Lucknow, the state capital.
"Over 1,000 people have been affected with encephalitis, and we are not sure when the fresh stock of vaccines will arrive," Mishra said. "In the absence of vaccine we cannot start the vaccination drive."
In 2005, more than 1,500 children were killed by the disease, but the numbers dropped sharply after the government started an annual vaccination drive in 2006.
Last year, about 400 children were killed by Japanese encephalitis in Uttar Pradesh. Officials had hoped to keep the death toll relatively low this year.
Uttar Pradesh's director general of health, Ishwar Sharan Srivastava, said the state had asked for the vaccines earlier — in time for the monsoon season's start in June — but only received them last week. He said they needed up to 1 million vaccines.
And Mishra said that of the 460,000 vaccines received, many had indicators that they had lost their potency. Officials from the federal Health Ministry said it was not immediately clear what happened.
"It is hard to tell as how these vaccines got spoiled. The exact reason could be ascertained only after tests," said Dr. Jagdish Chandra, a Health Ministry expert sent to investigate.
At least 234 children, all under 15 years, have died of the disease since June this year, and the death toll is likely to rise without vaccinations, Mishra said.
Encephalitis usually spreads in eastern parts of Uttar Pradesh during and after the June-to-September monsoon season, when pools of stagnant water provide breeding grounds for mosquitoes.
The mosquitoes transmit the virus from pigs and birds to humans. Since most infected people never develop symptoms, many adults are immune from earlier exposure — leaving young children most vulnerable.