The World Health Organization (WHO) has advised people in European countries to avoid unnecessary international travel to contain the spread of Covid-19.
Hans Kluge, the WHO's regional director, revealed that while official cases in Europe continue to fall, incidence rates in eight countries are of ongoing concern.
"The pandemic is not over yet," Kluge said on Thursday. "Increased mobility and interactions may lead to more transmission... In the face of a continued threat and new uncertainty we need to exercise caution and rethink or avoid international travel.
"(European leaders should) not make the same mistakes that were made this time last year that resulted in a resurgence of Covid-19 and saw health systems, communities and economies once again bear the full force of the pandemic."
Official weekly cases of Covid-19 have fallen by almost 60 per cent in Europe, from 1.7 million in mid-April to approximately 680,000 last week. Death rates have also fallen.
While many Europeans are hoping to enjoy a summer holiday in the next few months as lockdown measures ease, Kluge pointed out that the B.1.617 variant first identified in India has been found in at least 26 countries across Europe.
There is concern that international travel could increase the risk of this variant transmitting at an increasingly alarming rate in a similar way to the B.1.1.7 variant first identified in the U.K.
"We are still learning about the new variant, but it is able to spread rapidly and displace the B.1.1.7 lineage that has now become the dominant lineage in Europe," he said. "Neither testing nor receiving vaccines is a substitute for adherence to measures such as physical distancing and mask-wearing in public spaces or healthcare settings.
"Vaccines may be a light at the end of the tunnel, but we cannot be blinded by that light."
Although vaccines are believed to be effective against the new Indian variant, only 23 per cent of people across Europe have received their first dose of vaccine. Just 11 per cent of adults in the region have had both doses, and there is still uncertainty about how transmissible the Indian variant could be.
"We've seen this in several parts of the UK but also in other countries in the European region," said Catherine Smallwood, the WHO's senior European emergency officer, adding the WHO is "tracking it very closely".
"We're learning about it," she added. "We're pulling as much information as we can together in order to be making some more specific statements around its characteristics both in terms of transmissibility, but also in terms of its ability to evade any immunity."