Swiss regulators on Monday gave the green light to Johnson & Johnson's COVID-19 vaccine, after already authorising the jabs made by Pfizer-BioNTech and Moderna.

The Swissmedic regulatory authority said in a statement that it had authorised the use of the vaccine, which has the advantages of being a single-shot jab that can be stored with regular refrigeration rather than at ultra-cold temperatures.

"Following a careful review of all the submitted documentation, Swissmedic has granted the 'Covid-19 Vaccine Janssen' temporary authorisation," it said.

"This brings to three the number of vaccines officially authorised for distribution in Switzerland for the prevention of Covid-19," it said, adding that the jab could be used for those over the age of 18.

Switzerland was the first country on continental Europe to start using the Pfizer-BioNTech jab, and it has also signed off on another mRNA vaccine, produced by Moderna.

It has, however, not yet authorised the use of the AstraZeneca vaccine, saying last month that it would wait for more data on the "safety, efficacy and quality" of that jab. 

The Johnson & Johnson vaccine has shown an overall efficacy of 66.9 percent in clinical trials, but has proved more effective among older people and was shown to be 85 percent effective against serious illness.

Swissmedic also highlighted the fact that the vaccine had proven to be effective against more contagious variants of the virus first detected in Brazil and South Africa.

The vaccine has already been approved by the World Health Organization, the European Union, the United States, Canada and South Africa, among others.

Like much of Europe, Switzerland is bracing for a third wave of infections, and last week decided to postpone plans to loosen restrictions.

The country of 8.6 million people has to date counted more than 580,000 cases of Covid-19 and nearly 9,500 deaths.

So far, nearly 1.2 million vaccine doses have been administered in the country, and over 433,000 people have been fully vaccinated.