Ursula von der Leyen has reassured EU leaders she will ban coronavirus vaccines from leaving the EU if suppliers such as AstraZeneca fail to deliver again, as she faced questions over her handling of shortages. The European commission president’s pledge at a virtual summit came as leaders issued a statement promising to “accelerate the provision of vaccines”, with just 8% of the adult population having received a jab compared with 27% in the UK. “If companies don’t fulfil their contractual obligations, yet do export, the commission may decide to make a move under the export regime,” Von der Leyen told the heads of state and government during the private meeting, according to a senior diplomatic source. Last month the commission rushed through an emergency authorisation scheme to allow the EU member states to block exports. Speaking at the post-summit press conference, Von der Leyen said: “We want to see who is exporting where and I was very clear from the very start that is not directed against any kind of country but is focused on the question: does the company that is exporting a vaccine produced in Europe honour the contract in the European Union? “If we look at the pattern the vast majority of exports is done by BioNTech/Pfizer of 95% approximately. The rest by Moderna. Both of them are honouring their contract so that is fine with us. We are in discussions with AstraZeneca where there is room for improvement where fulfilment of the contract is concerned, so here we have a very close eye on what is going on.” The comments on Thursday evening followed a defence by AstraZeneca’s chief executive, Pascal Soriot, of his company’s record to a joint committee of the European parliament where he was grilled over a heavy shortfall in the 120m expected deliveries this quarter. He told MEPs, who had accused him of failing the EU while delivering to Britain, that the UK government had heavily funded the development of the Oxford/AstraZeneca vaccine, for which the government had a 100m order. Soriot said the “overwhelming” majority of doses made in its Belgian and Netherlands production facilities “remained in the EU” despite the suspicion within the commission that doses made for member states had leaked over to the UK. “I am disappointed that lower than expected output in our dedicated European supply chain has affected our ability to deliver, but I want to reassure that we are ramping up production and doing everything we can to deliver 40m doses in the first quarter of 2021 enabling vaccination of 10% of the EU population,” Soriot said. “The supply chain serving the UK is geared to supply 65 million people who live in the UK. The European community has 450 million people I believe. Even if we took the entire supply of the UK it would not make a huge difference to the European community.” Speaking to the same parliamentary committee, Franz-Werner Haas, the chief executive of the German pharmaceutical company CureVac, with whom the commission has a contract for 225m doses of its as yet unapproved vaccine, highlighted the unintended consequences of the commission’s policy that forces companies to seek authorisation for vaccine exports. “This has been hitting us somehow because we couldn’t get clinical trial material to Latin America,” Haas told MEPs. “We did then get immediate support from the commission as well as the German authorities. [But] for rather a small company, 600 people, certainly this adds an extra layer … We lost a week to ship the material which was necessary and is necessary to run the clinical trial.” Following the leaders’ summit, a statement was issued emphasising the determination to speed up the roll out of vaccines amid the heavy criticism. “We need to urgently accelerate the authorisation, production and distribution of vaccines, as well as vaccination,” they said. In a reference to the row with AstraZeneca, whose deliveries have been smaller than expected due to production problems, they added that “companies must ensure predictability of their vaccine production and respect contractual delivery deadlines”. Von der Leyen was also put under pressure from southern European countries and the Austrian chancellor, Sebastian Kurz, to speed up work on a common vaccination certificate that might in time be used as a “passport” to facilitate travel. This week the Guardian reported that “technical talks” had begun between officials in the UK and Greece over the potential format of such a document. In a sign of some nervousness on the issue in France and Germany, among others, where there are concerns that such a scheme will institutionalise discrimination, the leaders committed only “for work to continue on a common approach to vaccination certificates”, adding that they “will come back to this issue”. “First it must actually be clearly resolved that vaccinated people are no longer infectious,” the German chancellor, Angela Merkel, had said in a newspaper interview before the summit. “As long as the number of those who have been vaccinated is still so much smaller than the number who are waiting for vaccination, the state should not treat the two groups differently.” Von der Leyen said in the press conference that member states would be able to choose how to use vaccine certificates once a common model was organised. Merkel had also used her media interview to give her full backing to the Oxford/AstraZeneca vaccine, following evidence that people were rejecting it in light of a slew of bad publicity, including Emmanuel Macron’s unsubstantiated claim that it was “quasi-ineffective” in over-65s. Asked whether she would take the vaccine, Merkel responded that at the age of 66 she was not in the recommended group. The German authorities have initially suggested it only be used in younger groups given a lack of data on efficacy among the over-65s. Rasmus Bech Hansen, the chief executive of the data analytics company Airfinity, said supply remained the major issue for the EU, with a lack of readiness to then distribute the stocks exacerbating differences between the member states. According to the latest Airfinity analysis, Malta can expect to reach herd immunity by fully vaccinating 75% of its adult population by 8 August, but the current trajectory for Bulgaria and Latvia is for a similar level of protection to be secured in late October. France, where Macron has come under criticism for his government’s faltering vaccination efforts, may have to wait until 26 September to achieve herd immunity, although an acceleration of the programme could result in this date being brought forward.