"Ladies and gentlemen, we are at a decisive moment," Commissioner Stella Kyriakides said at a news conference Thursday. "Today we're here to call on everyone to act decisively. It might be our last chance to prevent a repeat of last spring."
Kyriakides added that autumn and winter are the time of year for more respiratory illnesses, including seasonal influenza.
"To prevent what could potentially be a lethal 'twin-demic' of Covid-19 and the flu -- which could overburden our health systems and lead to more loss of life -- we need to increase the coverage of vaccination rates," she warned.
The commissioner said that people should also not lower their guard because "the crisis is not behind us."
"We must prevent a situation where governments feel they have no choice but to improve imposed generalized lockdowns.
"[Such lockdowns] will be detrimental -- detrimental to our mental health, detrimental to our economies, detrimental to the well-being and education of our children, detrimental to our working and daily lives. We have to take measures that will protect those around us, whether they're parents or grandparents or those vulnerable in our societies."
This comes as global health experts warned that the arrival of the flu season was a "huge concern" because of the potential burden on health services. The pressure on hospitals is also increased by the number of "long-haulers," those who are suffering adverse effects from coronavirus more than a month after they were ill.
The experts said Europe once again needs to "flatten the curve" through social distancing and hygiene measures, as well as robust testing and contact tracing as cases rise and governments bring in new measures in an attempt to stop the virus spread.