India plans inhalable vaccine trials

 Clinical trials for the first dry powder measles vaccine are scheduled to begin in March 2010 in India. The new vaccine – a dry powder that can be inhaled directly into the lungs – is likely to be more effective as it mimics the natural route of the infection and has given the Indian government hope in the fight against the disease, which kills more than 200,000 children each year.

The vaccine is being developed by Robert Sievers from the University of Colorado, US, and the Serum Institute of India (SII), Pune. If the vaccine passes safety and efficacy tests, the Pune-based vaccine manufacturer is looking at a demand of 400m doses of measles vaccine annually.

‘We are waiting for regulatory permissions and will start the trials around the end of March next year. So far, the vaccine has been effective on animal models. The animal studies are ongoing but we already know that when the vaccine is inhaled and goes directly to the lungs, the immune response is better,’ said additional medical director, SII, Prasad Kulkarni, who will be heading the research team. The institute will conduct human trials next year with 30 adults to test the vaccine’s effectiveness.

Besides being safe and painfree, the dry powder inhalable measles vaccine, if found to be as effective as the vaccine currently in use, will eliminate the risks associated with the use of poorly sterilised needles. ‘In developing countries, we require vaccines, which can be stable outside the cold chain.

Being safe and pain-free work in favour of the new vaccine, but what is more significant is that the new vaccine will eliminate the risk of spreading HIV or hepatitis from dirty needles. If the trials are successful, countries like India, which seriously lack proper cold chain facilities, will greatly benefit from this vaccine as it is likely to increase the coverage under the national vaccination programme,’ said Sushil Kabra, paediatric pulmonologist, All India Institute of Medical Sciences.

The vaccine is prepared by mixing a weakened measles virus with supercritical carbon dioxide to produce microscopic bubbles and droplets, which dry into an inhalable powder. The powder is puffed into a small, cylindrical plastic sack, with an opening like the neck of a plastic water bottle, and administered nasally.

‘We will be comparing two models for packaging of the vaccine. Both are simple devices but will be studied in greater detail during the clinical trials and compared,’ says Kulkarni. He added that the vaccine should be on the market by 2013 if all goes to plan.

According to the Indian Ministry of Health and Family Welfare, almost 25m Indian children received measles vaccines in the last three years, with 16m of those vaccinated in 2008 alone. The disease kills about 500 children every day, and only 66% of children, less than 50% in some states, receive vaccinations.