India has clamped a ban on the use of the measles vaccine manufactured by a public sector firm following the death of four vaccinated children on Tuesday.
The incident took place in the southern Indian state of Tamil Nadu after they were administered the vaccine produced by that firm.
"All the state governments have been instructed to stop the use of the measles vaccine manufactured by the Indian Immunological Limited until further orders," Union Health Minister Anbumani Ramadoss told reporters in the national capital of New Delhi on Thursday.
An order of 90 lakh units of vaccine had been placed with the company, which is a wholly owned subsidiary of the National Dairy Development Board. It had supplied 45 lakh units in the last four months.
Samples of the vaccine had been sent to the Central Research Institute (CRI
), Kasauli for further testing, Ramadoss said.
The Union Health Ministry also sent a high-level team, led by Director of National Institute of Communicable Diseases (NICD) Shivlal, to the state to inquire into various aspects of the administration of the vaccine.
The committee, comprising members from the Indian Council of Medical Research, the National Institute of Communicable Diseases and the Directorate-General of Health Services, and the Drug Controller-General of India, would visit Tiruvallur and inquire into the quality of the vaccine, status of the cold chain, quality of diluents (substance that dilutes the strength of a solution or mixture), distribution and administration of the vaccine including the possibility of human error. Experts of the National Polio Surveillance Project of the World Health Organisation had already been deputed to Tamil Nadu to assist the State government in investigations.
Ramadoss said the same vaccine was being administered in other parts of the country over the last four to five months and there have been no adverse incidents. "This is making us think that it might have been some problem at the local level," he reasoned.
He was also confident that there would be no shortage of vaccines and the national mass immunization would go on unhindered. There were other sources from which the required vaccines could be procured, he said.
When contacted, the Hyderabad firm's Human Vaccine Division General Manager, Dinar Kumar, said they were waiting for 'conclusive results' from the investigation taken up by Tamil Nadu health authorities.
It was only in April last year that the Indian Immunological Limited (IIL) had received commercial approval from the Government of India to manufacture measles vaccine.
"We do not know how the Tamil Nadu authorities are investigating the incident. Nobody from Tamil Nadu has till now contacted us. Our facilities meet WHO standards. The vaccines produced by us are sent to Kasauli, for testing before being released to any governmental agency," Kumar maintained. The HBI is also supplying measles vaccine to other States through the Government of India.
The vaccine manufacturing facility of IIL at Gachibowli was recently set up to produce human vaccines for diphtheria, tetanus, hepatitis, measles and pertussis. Incidentally, the IIL has been supplying Tamil Nadu anti-rabies vaccine for the past six-years.
Any chance of vaccines getting contaminated arises during handling and storage. While transporting, the vaccines have to be maintained or kept at temperatures ranging between two and eight degree Centigrade till they are administered.
The challenge here is not to break the cold-chain, because once it breaks, the chances of contamination are more.
"This is known as cold-chain procedure and a break here would lead to contamination. Vaccines are kept in custom-made thermocol boxes and sent from the manufacturing unit to the warehouse, where vaccines are stored.
From the warehouse, it's the responsibility of local health authorities to maintain the vaccines in the stipulated temperatures.
"The vaccines supplied to various State governments come under the Expanded Programme of Immunisation (EPI). Designated government officials under EPI visit our facility to pick samples from a batch and send them to Kasauli. We can't release the vaccines till we get a nod from CRI," Mr. Kumar said.