India will halt coronavirus vaccinations this weekend to upgrade software used to coordinate its campaign, the health ministry said on Friday, preparing to expand the programme after infections surged in some states.With the world’s highest tally of infections after the United States, India began its vaccination drive on Jan. 16, covering nearly 11.5 million health and front-line workers, against a target of 300 million by August.

“The countrywide vaccination exercise is being exponentially expanded,” the ministry said in a statement, adding that a new version of its Co-Win digital platform was being rolled out at the weekend.

Co-Win, wrapped into a government mobile telephone app, is being widely used to fix vaccination appointments, allow health authorities to monitor supplies and download proof of immunisation.

Initial software glitches had slowed India’s vaccine roll-out, forcing many states offline.

Last month a government official told Reuters software changes would eliminate any glaring weaknesses when the campaign expands from Monday to cover people aged 60 and those over 45 who suffer medical conditions.

Authorities estimate it could handle as many as 10 million vaccinations a day, up from an average of 300,000 now.

Co-Win forms part of a government contact-tracing app “Aarogya Setu”, or Health Bridge, downloaded by nearly 170 million people.

India’s infections rose 16,577 in the past 24 hours to stand at 11.06 million, health ministry data show, while the death toll rose 120 to reach 156,825.

A recent surge in the western state of Maharashtra and the southern state of Kerala accounted for the bulk of infections and deaths.