Europe is “on thin ice” in its battle against Covid-19, German Chancellor Angela Merkel said on Thursday as EU leaders agreed vaccinations should be sped up to fight the highly contagious Delta variant. A stronger response to the pandemic was a main topic of discussion among EU leaders at a meeting in Brussels, where they also acknowledged that the bloc’s borders should be reopened cautiously. In what might have been her last government declaration to the German Parliament, Mrs Merkel said the number of Covid-19 cases in the 27-nation bloc continued to decline while vaccination rates climb. “But even though there is reason to be hopeful, the pandemic isn’t over, in particular in the world’s poor countries,” she said. “But in Germany and Europe, we’re also still moving on thin ice. We need to remain vigilant. “In particular, the newly arising variants, especially now the Delta variant, are a warning for us to continue to be careful.” On his arrival in Belgian capital, French President Emmanuel Macron also urged European countries to remain “vigilant” to properly tackle the Delta variant, and to adopt a co-ordinated approach when reopening borders to other countries. In a report this week, the European Centre for Disease Prevention and Control projected that the Delta variant would account for 90 per cent of all coronavirus infections across the continent by the end of August. The agency in Stockholm said people who had received only one shot of a vaccine were still vulnerable to the Delta strain and that about 40 per cent of people over 60 have yet to receive both doses. The ECDC said its modelling estimated that any relaxation of the Covid-19 protocols “could lead to a fast and significant increase in daily cases in all age groups", possibly reaching a similar peak to that of last autumn. In their conclusions on Covid-19, EU leaders insisted on “the need to continue vaccination efforts and be vigilant and co-ordinated with regard to developments, particularly the emergence and spread of variants". Germany has pressed for EU countries to co-operate on quarantine for travellers from areas where variants are particularly prevalent. This includes England where the Delta variant, first detected in India, is already the predominant strain. EU leaders also praised the adoption of Covid-19 certificates before the summer holiday season, with many calling for its introduction across the bloc. The EU has devised a joint digital travel certificate for people who are fully vaccinated, freshly tested or recently recovered from the coronavirus. The free certificates allow people to move between European countries without having to enter quarantine or undergo more coronavirus tests on arrival. Belgium, Spain, Germany, Greece, Bulgaria, Croatia, the Czech Republic, Denmark and Poland are already using the system. The other EU countries are expected to start using it on July 1.