MUMBAI - India may not need to vaccinate all of its 1.3 billion people if it manages to inoculate a critical mass and break the transmission of the coronavirus, senior government officials said on Tuesday.

Indian Prime Minister Narendra Modi, who toured the facilities of three vaccine makers over the weekend, has emphasized the importance of a vaccine to rein in COVID-19.

In October, he said that the government was preparing to reach every single citizen as soon as a vaccine was ready.

World Health Organization experts have pointed to a 65%-70% vaccine coverage rate as sufficient to reach population immunity.

"The government has never spoken about vaccinating the entire country," Rajesh Bhushan, the top bureaucrat in India's federal health ministry, told a news conference on Tuesday without reference to Modi.

India currently has the world's second-highest number of coronavirus infections, behind only the United States, with 9.46 million cases and 137,621 deaths.

India recorded 31,118 new coronavirus cases on Tuesday, the lowest daily tally since Nov. 17, data from the health ministry showed.

"...If we are able to vaccinate a critical mass of people, and break that virus transmission, then we may not have to vaccinate the entire population," Balram Bhargava, Director General of the state-run Indian Council Of Medical Research, said at the press briefing.

India's plan to roll out a COVID-19 shot in the first few months of 2021 wouldn't be impacted by an alleged adverse reaction during AstraZeneca's COVID-19 vaccine trial, Bhushan said.

A 40-year-old Indian man said in a complaint over the weekend that he had suffered serious “neurological and psychological” symptoms after receiving the vaccine in a trial being run by the British drugmaker’s partner, Serum Institute of India.

The incident is currently under investigation.

(Reporting by Shilpa Jamkhandikar. Additional reporting by Anuron Kumar Mitra in Bengaluru; Editing by Kim Coghill and Nick Macfie) ((shilpa.jamkhandikar@thomsonreuters.com;))