Global healthcare major Johnson & Johnson on Tuesday said it has sought approval from India's drug regulator to conduct a bridging clinical trial of its single-dose Covid-19 vaccine in the country.

The US Food and Drug Administration (USFDA) had in February approved Johnson & Johnson's Covid-19 vaccine that works with just one dose for emergency use.

"Johnson & Johnson is partnering with health authorities and the world's best scientists to provide the safety and efficacy data necessary to support worldwide emergency use of the Janssen Covid-19 vaccine candidate," the company said in a statement.

This comes close on the heels of the central government last week deciding to fast-track emergency approvals for all foreign produced coronavirus jabs that have been given a similar nod by the World Health Organization or regulators in the United States, Europe, Britain or Japan.

Such vaccines will be given emergency use approval mandating the requirement of post-approval parallel bridging clinical trial in place of conduct of local clinical trial under the provisions of the New Drugs and Clinical Trials Rules 2019, the health ministry had said.

"In line with this commitment, we have submitted an application to the Drugs Controller General of India (DCGI) requesting approval to conduct a bridging clinical study of our single-dose Janssen Covid-19 vaccine candidate in India to comply with local regulations", the statement added.

Johnson & Johnson's vaccine can be stored at refrigerator temperatures.

So far, two vaccines -- one developed by Oxford University and AstraZeneca and the other developed by Bharat Biotech in collaboration with the Indian Council of Medical Research - National Institute of Virology -- are being used in India.

Both the vaccines are being manufactured within the country by domestic firms. While the Oxford/Astrazeneca vaccine 'Covishield' is being manufactured by Serum Institute of India, the indigenously developed 'Covaxin' is being manufactured by Bharat Biotech.

A third vaccine Sputnik V -- developed in Russia and to be imported and sold in India by Dr Reddy's Laboratories -- has also been approved by the Indian drug regulator.

The government, meanwhile, on Monday decided to expand its vaccination drive by allowing everyone above 18 years of age to get vaccinated from May 1 and permitted state governments, private hospitals and industrial establishments to procure the doses directly from manufacturers.

A bridging study is defined as a study performed in the new region to provide pharmacodynamic or clinical data on efficacy, safety, dosage and dose regimen in the new region that will allow extrapolation of the foreign clinical data to the population in the new region.