But it took a mild epidemic of chicken pox in the Capital to kick-start an earnest debate on the need for a vaccine for a self-limiting disease that is neither fatal nor recurring. The vaccine helps people develop their immunity, but in some cases, it is necessary to give a ready-made form of immune protection called Varicella-Zoster Immune Globulin (VZIG). This protects those who have been exposed to chicken-pox and whose immune systems are either too young or too weak to fight the disease, like newborns whose mothers had chicken-pox at the time of delivery; children with leukemia, AIDS; or those on drugs to suppress the immune system.

Experts recommend that the first dose of Varicella vaccine, which is effective in 90 per cent of cases, should be given between 12 and 18 months. If a child hasn't been vaccinated in early childhood, 12 years is the best time to administer a dose. Though some people develop chicken-pox even after vaccination, they report milder symptoms with fewer blisters.

But does India need the vaccine? Says B.W. Lee, Associate Professor of Paediatrics, National University, Singapore, who was in the Capital recently to promote the vaccine: ``Though chicken-pox is a self-limiting disease, the vaccine can prevent discomfort and suffering in patients, especially adults.''

Still, the general opinion in Indian medical circles is that the vaccine is something India can do without it. Says Anupam Sibal, Consulting Paediatrician, Indraprastha Apollo Hospital: ``Prescribing a vaccine for a self-limiting disease in a country, where deadlier ones are being ignored would be rather unethical.''

Arvind Taneja, Consulting Paediatrician, Holy Family, and an expert on infectious diseases, feels India is still not in a position to include chickenpox vaccination in immunisation programmes for children. ``One look at the economic development here and you will know that we don't have the resources,'' he points out. Priced at Rs 1,400, the vaccine does not come cheap. ``It should be prescribed only to those who have not had chicken-pox till the age of 12,'' Taneja adds.

Moreover, not much is known about its long-term effects, he points out. One risk is that the immunity may wear off after a number of years. Children may be protected from varicella infection in their early years only to become susceptible to it when they are older. Few experts, however, feel that it is there responsibility to keep their patients informed. Says Krishan Chugh, Consulting Paediatrician, Ganga Ram Hospital: ``The vaccine is effective, so it's best to let the patient decide whether he wants it or not''.