Alain Berset said the Swiss approach put the emphasis on personal responsibility — but accepted that it had not worked.
The virus will not vanish any time soon, he added, despite the roll-out of vaccinations.
In March, during the first wave of infections, Switzerland was not hit as hard by Covid-19 deaths and did not impose as strict a lockdown as some other European states. It then eased off its restrictions in stages.
From just three new cases recorded on June 1, infections rose slowly before rocketing in October, when cases, hospitalisations and deaths began doubling from week to week.
Asked about Switzerland's mistakes, Berset told national broadcaster SRF: “There were some. In summer, we had the feeling that the worst was over. We were too loose. And then we were far too optimistic when we thought we could reopen the major events in autumn,” notably football and ice hockey matches.
In early November, Geneva had the worst per capita infection rates in Europe.
With a population of 8.6 million, Switzerland is logging a stubbornly high rate of around 5,000 new cases and 100 deaths a day.
“The Swiss way has a price. It requires personal responsibility, reason and foresight from everyone. If that doesn't work, we have to tighten the measures. We did that,” Berset said. “The good thing about the current situation is that we still have reserves.”
From Tuesday, bars and restaurants began closing again across the country in a bid to rein in the outbreak.
Berset said that in making decisions during the crisis, he ultimately had to rely on “gut feeling”.
“In overcoming a crisis, the worst part is simply not doing anything, getting stuck and submitting to it. For sure, if you make mistakes, you have to correct them as quickly as possible.”
Switzerland started its Covid-19 vaccine rollout on Wednesday, with a care home resident in her 90s receiving the first shot just four days after the Pfizer-BioNTech vaccine was authorised.
“This virus won't be gone anytime soon. It will stay, despite vaccinations and better medication,” Berset said. “Then there are the consequences of the crisis, which should not be underestimated: economic consequences, social ones.”
As for rebuilding society in the wake of the pandemic, Berset said: “My fear is that we will miss this opportunity.”
He called for the strengthening of international organisations in response to the crisis, notably the Geneva-based World Health Organization, which has been harshly criticised by outgoing US President Donald Trump.
“Without the WHO, everything would be much worse now,” said Berset.