Usually, Vienna's trams can be seen gliding past Baroque palaces, but this winter, one of them will take on a new role: helping Viennese get the seasonal flu vaccine.

The "vaccine tram" was unveiled on Thursday as part of a campaign being launched by the city to provide residents with free vaccinations and thereby reduce any potential pressure on hospitals from coronavirus patients.

The Viennese are being urged to either register for a spot on the tram or to head to one of several health centres and around 600 doctors' offices where the vaccine is being administered. "We think we can have a threefold increase of the vaccination rate this year and we hope to motivate many Viennese to get vaccinated," Michael Ludwig, Vienna's mayor, said at an event to unveil the tram.

He added that the city has acquired 400,000 vaccines, enough to cover about 25 percent of the population. "The aim is to get a large number of Viennese residents inoculated... so that the capacities in the hospitals remain free because we don't know what this winter will hold," in terms of coronavirus infections, Ludwig said.

Currently, Vienna accounts for more than half of Austria's coronavirus infections, with close to 4,500 active cases. Medical experts have warned that the medical system could come under strain if it is forced to deal with an influx of seasonal flu and coronavirus patients at the same time.