Brussels, June 18 : The European Medicines Agency (EMA) said that it may not enforce a 50 per cent efficacy threshold for Covid-19 vaccines but will still analyse the entirety of the evidence before making a decision on market authorisation. EMA's head of Biological Health Threats and Vaccines Strategy, Marco Cavaleri, said on Thursday that although the regulator and others were asking for studies that prove that efficacy is at least 50 per cent, "EMA always felt difficult to define upfront a threshold", reports Xinhua news agency. "We will consider the benefits and the risks demonstrated by the vaccine and come up with a decision on whether the vaccine can be approved or not. "In other words, we will need to look at the data and only then can we understand that what has been proven in terms of efficacy and safety could be sufficient for a market authorisation," he added. Cavaleri made the remarks after Germany's CureVac said on Wednesday that the company's Covid-19 vaccine was shown to be just 47 per cent effective in an interim analysis of its late-stage trial. The European Union (EU) has secured up to 405 million doses of the CureVac vaccine. "We know that variants could impact somehow the performance of the vaccines. The vaccines we have approved so far are holding quite well against the majority of the variants that are circulating right now," Cavaleri said. Earlier on Thursday, the European Commission called for patience and caution while awaiting the results of EMA's final assessment. "The information that is about the efficacy rate seems to point to some preliminary, or not complete or final results. Of course, it will be important for us to have the final set of complete results regarding efficacy before taking any steps or proceeding in our discussions with the company," said Dana Spinant, deputy chief spokesperson of the European Commission. The results of this preliminary analysis have been communicated to EMA, which has been conducting a rolling review of the Curevac vaccine since February. If the vaccine is cleared, it will be granted a conditional marketing authorisation, and EU member states will be able to purchase doses. In case of not getting the green light, the EU's contract with CureVac could be terminated, according to Stefan De Keersmaecker, the European Commission's spokesperson for health. Currently, four Covid vaccines have been greenlighted by EMA, namely BioNTech/Pfizer, Moderna, AstraZeneca and Johnson & Johnson. CureVac is under rolling review, along with China's Sinovac, Russia's Sputnik V and the US' Novavax. /IANS