Patrick Mathys, the health ministry's crisis management chief, told a press conference that Switzerland's infection rates were still troubling despite decreases in deaths and hospitalisations.
He voiced concern about the spread of new, seemingly more contagious variants of the virus first detected in Britain and South Africa.
Some 127 such cases have been found so far in Switzerland — and rather than just being imported cases, the strains are now spreading domestically, he said.
Mathys estimated that five to six percent of positive tests in Switzerland were now linked to these variants — up from 1.4 percent in the first week of January.
Switzerland has secured around 15.8 million eventual Covid-19 vaccine doses, in deals with three manufacturers.
It has signed contracts for around three million doses from Pfizer-BioNTech, around 7.5 million from Moderna, and around 5.3 million from AstraZeneca.
With each of the three different vaccines, two doses are required per person.
By January 18, Switzerland should have received enough Pfizer and Moderna doses to vaccinate four percent of the adult population with both shots, the health ministry said.
The country of 8.6 million people has seen coronavirus infections gradually decrease from a spike in early November.
However, the government remains concerned and is likely to confirm Wednesday that the restrictions it has imposed will be extended until the end of February. Nearly 485,000 people have tested positive for the virus, while 7,753 people have died.