NEW DELHI (Reuters) - Serum Institute of India and Bharat Biotech are expected to pursue late stage clinical trials of intranasal COVID-19 vaccines in the coming months once they receive regulatory approval, Health Minister Dr Harsh Vardhan said on Sunday. Vardhan said the late stage trial generally involves thousands of participants, sometimes 30,000 to 40,000. Of the vaccines currently in Phase 3 trials, all are administered by injection, according to the World Health Organization (WHO). On Saturday, India’s Dr Reddy’s Laboratories Ltd and the Russian Direct Investment Fund (RDIF) said they have received renewed approval to conduct late-stage clinical trials in India of the Russian COVID-19 vaccine. India’s coronavirus infections rose by another 61,871 over the past 24 hours, data released on Sunday showed, although the health ministry said it is seeing a trend of steadily declining active cases. The Indian Council of Medical Research (ICMR) said it will revisit its protocol for COVID-19 treatment after the WHO found some of the commonly used drugs, including remdesivir, had little or no impact on a patient’s chances of surviving, local media reported earlier on Sunday.