Berlin, March 28 : German Health Minister Jens Spahn on Saturday said he thinks a lockdown lasting 10-14 days is necessary to get the country's ballooning coronavirus outbreak under control. "If we take the figures, including the developments today, we actually need at least another 10 or 14 days in which we really shut down our contacts, our mobility," he said, DPA news agency reported. According to Spahn, Germany needs a lockdown over next week's Easter holidays similar to what occurred last year, when Germans were clearly told to stay at home and avoid all contacts. Spahn also said that Germany would likely begin administering the single-shot coronavirus vaccine developed by US manufacturer Johnson & Johnson starting in mid-April, giving Germany's so-far slow vaccine roll-out a boost. The European Union's medicines regulator endorsed the vaccine - the fourth to be approved in the bloc - on March 11, but deliveries have yet to start. Earlier on Saturday, Germany's intensive care doctors said a two-week hard lockdown was the only way to avoid overwhelming hospitals as the country grapples with a third wave of infections. A mix of hard lockdown, vaccinations and testing is necessary to "prevent intensive care units from being overflowed," the head of the German Interdisciplinary Association for Intensive Care and Emergency Medicine, Christian Karagiannidis, told the Rheinische Post daily. He called on politicians to put an immediate stop to any planned openings in light of the rapidly rising case numbers. "I ask politicians not to abandon hospital staff," added Karagiannidis. The Robert Koch Institute (RKI) for disease control on Saturday reported its highest seven-day incidence rate per 100,000 inhabitants since mid-January -- 124.9. The day before, it had stood at 119,1. Germany's coronavirus strategy was thrown into confusion earlier this week, when the government of Chancellor Angela Merkel made a spectacular u-turn on a plan to tighten an existing nationwide lockdown over Easter, citing legal and logistical problems in implementing it. The uncertainty has caused discord among the premiers of Germany's 16 federal states, some of whom are refusing to go along with a plan to return to a harder lockdown in areas where the infection rate remains comparatively low. Merkel often appeals for a unified response but Germany's federal system gives the states significant leeway to set rules. A recent poll, however, showed that more people were again in favour of tightening measures rather than loosening them. According to a poll by the broadcaster ZDF, 36 per cent want to tighten measures while 31 per cent wants to maintain the current restrictions. Only a quarter of respondents said they wanted to relax measures. Berlin on Saturday implemented new rules under which all retailers that re-opened at the beginning of the month, when Germany's lockdown was eased, can keep welcoming customers, but they have to provide a negative test result. Supermarkets, pharmacies and drugstores are exempt from the requirement, which goes into effect on Wednesday, Mayor Michael Mueller said after a meeting of the city-state's Senate. Museums and businesses that offer close-contact services, such as hair salons or tattoo studios, may also remain open but patrons must present a negative test result as well. Pilot projects for reopening further cultural institutions under strict limitations, such as concert halls or clubs, where put on ice, Mueller said. /IANS