New Delhi, Feb 3 (IANS) Leading vaccine manufacturer Bharat Biotech Wednesday delivered its billionth vaccine dose and announced to invest Rs.250 crore in two years to carry forward clinical trials in different disciplines.

'While the manufacture and sale of a billion doses gives us a great sense of accomplishment, we realise that life saving vaccines are still unavailable to millions of people and there is a lot more work to be done,' said company chairman and managing director Krishna M. Ella.

'It has taken Bharat Biotech nearly 10 years to reach its first billion doses and the second billion doses would be reached in less than five years,' Ella said in a statement.

'We are committed to research and development of innovative vaccines to address global infectious diseases,' he added.

The company said it intends to inject 30 percent of its revenues in research and development.

Bharat Biotech manufactures vaccines to fight rabies, polio, hepatitis-B, typhoid, diphtheria, pertussius, tetanus and haemophilus influenza B.

Currently, the company has few more vaccine development projects such as rota virus vaccine, typhoid conjugate vaccine, malaria vaccine, Japanese encephalitis vaccine, chikungunya vaccine and swine flu vaccine.