Angela Merkel has said travellers from the UK should be quarantined wherever they arrive in the EU, as the union’s agency for disease control forecast that the Delta variant of Covid will account for 90% of cases in member states by the end of August. Ahead of Thursday’s summit with fellow EU leaders, the German chancellor said she wanted better coordination to fight the spread of the highly transmissible variant that has surfaced strongly in the UK and is now bedding down in the bloc. “In our country, if you come from Great Britain, you have to go into quarantine – and that’s not the case in every European country, and that’s what I would like to see,” Merkel told the Bundestag lower house of parliament. Merkel has criticised Portugal in recent days, where the entry of British tourists is permitted without quarantine. The French government also allows double vaccinated travellers from the UK to enter the country without going into isolation. Merkel’s call for a uniform policy on UK travellers came as Dr Andrea Ammon, the director of the European Centre for Disease Prevention and Control (ECDC), said the Delta variant was likely to spread widely among young people this summer, and warned people with a single jab that they were at risk. In a sombre statement at a time when many EU countries are looking to relax restrictions and facilitate travel through a Covid passport, Ammon said there remained too many people in the more vulnerable age groups in the union who were not fully vaccinated. The ECDC’s modelling suggests that without maintenance of the current Covid restrictions and a sharp acceleration in vaccination, there is likely to be a wave of infection, deaths and hospitalisation similar to that experienced last autumn. Ammon called on younger people who may not have received their full complement of jabs to strictly keep to social distancing regulations. She added that the EU’s public health authorities should accelerate their vaccination efforts to save lives as the ECDC published its risk assessment of the Delta variant. The ECDC’s latest published data suggests that 33.9% of adults in the EU/EEA are fully vaccinated, and 57.1% have had at least a single dose. “The Delta variant is more transmissible than other circulating variants and we estimate that by the end of August it will represent 90% of all Sars-CoV-2 viruses circulating in the European Union,” Ammon said. “Unfortunately, preliminary data shows that it can also infect individuals that have received only one dose of the currently available vaccines. “It is very likely that the Delta variant will circulate extensively during the summer, particularly among younger individuals that are not targeted for vaccination. This could cause a risk for the more vulnerable individuals to be infected and experience severe illness and death if they are not fully vaccinated.” Ammon, a former adviser to the German government, said the positive news was that two doses of all the available vaccines in Europe provided “high protection against this variant and its consequences. However, about 30% of individuals older than 80 years and about 40% of individuals older than 60 years have not yet received a full vaccination course in the European Union.” The Delta variant, which has slowed down the UK’s reopening, is believed to be 40% to 60% more transmissible than the original virus and is thought to be associated with higher risk of hospitalisation. The ECDC’s modelling suggests 70% of new Covid infections will be due to this variant in European economic area by early August and 90% of infections by the end of that month. The EU agency has further modelled that a 50% reduction in non-pharmaceutical interventions by September, such as permitting the staging of large events, will lead to an increase of infection across all age groups. Ammon said the variant put the cumulative efforts to control the pandemic at risk and required “immediate actions” from national authorities. She said: “There are still too many individuals at risk of severe Covid-19 infection whom we need to protect as soon as possible. Until most of the vulnerable individuals are protected, we need to keep the circulation of the Delta virus low by strictly adhering to public health measures, which worked for controlling the impact of other variants. “It is very important to progress with the vaccine rollout at a very high pace. At this stage it becomes crucial that the second vaccination dose is administered within the minimum authorised interval from the first dose, to speed up the rate at which vulnerable individuals become protected.” Ammon added: “I am aware that it requires a significant effort from public health authorities and the society at large to achieve this goal. “But now is the time to walk the extra mile. We have several safe and effective vaccines available and every single infection prevented now through our compliance with public health measures, is a life that can be saved by vaccination.”