The World Health Organization's European director Hans Kluge said on Thursday Covid-19 transmission rates in Europe remained too high, putting health services under severe strain, and therefore it was "too early to ease up".
"We need to be patient, it will take time to vaccinate," he told an online briefing. "We have learned harsh lessons - opening and closing, and reopening (societies) rapidly is a poor strategy" in seeking to curb coronavirus contagion, he said.
"Transmission rates across Europe are still very high, impacting health systems and straining services, making it too early to ease up," Kluge said. "Pushing transmission down requires a sustained, consistent effort. Bear in mind that just over 3% of people in the region have had a confirmed Covid-19 infection. Areas hit badly once can be hit again."
Kluge said a total of 35 countries in Europe had launched vaccination programmes with 25 million does administered so far.
"These vaccines have shown the efficacy and safety we all hoped they would...This monumental undertaking will release pressure on our health systems and undoubtedly save lives."
He said continued high rates of transmission and emerging variants of the virus made it urgent to vaccinate priority groups, but said the rate of vaccine production and distribution was not yet meeting expectations.
"This paradox, where communities sense an end is in sight with the vaccine but, at the same time, are called to adhere to restrictive measures in the face of a new threat, is causing tension, angst, fatigue, and confusion. This is completely understandable in these circumstances."