Switzerland, which to date has approved COVID-19 shots from Pfizer, Moderna and Johnson & Johnson, has placed orders for five million doses of CureVac's vaccine. It is a so-called mRNA vaccine, like those from Moderna and Pfizer that are already on the market.
"The duration of the rolling review will depend on the completeness of the data submitted by CureVac and the results of the clinical trials, and cannot therefore be predicted," Swissmedic said.
The European Union in November secured up to 405 million doses of CureVac's two-shot vaccine, which has yet to win regulatory approval, the company's only large supply contract so far.
Europe's choppy vaccine rollout hit more trouble this week after J&J suspended shipments of its COVID-19 shot and Denmark said it would drop a similar vaccine from AstraZeneca over very rare cases of blood clotting.
The EU has so far approved three vaccines -- Pfizer-BioNTech, Moderna and AstraZeneca-Oxford. Three other vaccines are under "rolling review" by the Amsterdam-based EMA -- Novavax, CureVac and Russia's Sputnik.
Portugal's public health system is on the verge of collapsing as hospitals in the areas worst-affected by a worrying surge in coronavirus cases are quickly running out of intensive care beds to treat COVID-19 patients.
The ministry official, speaking on condition of anonymity, said Germany signed a memorandum of understanding with CureVac on Aug. 31 for the supply of 20 million doses of its vaccine under development.
The internal health ministry document dated Jan. 7 and seen by Reuters had the same figures.