US President Joe Biden criticised Donald Trump on Friday for failing to secure sufficient Covid-19 shots. As he toured a Pfizer factory in Michigan, Mr Biden said his predecessor “failed to order enough vaccines. Failed to mobilise the effort to administer the shots. Failed to set up vaccine centres.” Mr Biden sought to reassure the public that the shots are safe and described efforts by his administration to increase supplies and vaccination sites. He also tried to rally support for the $1.9 trillion economic stimulus plan he proposed in response to the pandemic. He said variables will affect how long the virus will plague the US but that he believes the country will be approaching normality by the end of the year. “And, God willing, this Christmas will be different than last. But I can’t make that commitment to you,” he said. The plant, in Portage, on the outskirts of Kalamazoo in south-west Michigan, is Pfizer’s largest factory. There, the company’s Covid-19 vaccine is made and filled into vials before being shipped for distribution. Mr Biden’s visit was only his second trip away from the East Coast since taking office last month. On Tuesday, he appeared at a CNN question-and-answer session with the public in Milwaukee, Wisconsin. Last week, he toured the National Institutes of Health headquarters in Maryland to learn about federal research on the virus. Since taking office, Mr Biden has ordered an additional 100 million doses apiece of the Pfizer-BioNTech and Moderna vaccines, bringing the total to 600 million, enough for 300 million people. Both vaccines are administered in two doses. The president said onTuesday that Pfizer agreed to speed up shipments after Mr Biden invoked the Defence Production Act, which enables the government to nationalise manufacturing in emergencies. Despite the president’s criticism of Mr Trump, Mr Biden’s administration has made only modest changes to its predecessor’s vaccine plan. It is invoking agreements reached under Donald Trump to expand the US supply. The Trump administration last year bought 200 million doses of the Pfizer-BioNTech Covid-19 vaccine and obtained options for another 400 million. Mr Trump’s team also ordered 200 million doses of Moderna’s vaccine, with options for 300 million more. On Friday, Pfizer chief executive Albert Bourla spoke of Mr Biden as a “great ally” who helped obtain materials to expand capacity. Mr Bourla said his company would use more of its manufacturing capacity and work with new suppliers to step up production of the vaccine. Mr Biden has regularly touted his administration’s progress accelerating vaccinations, and encouraged any American with the opportunity to do so to have the shots. “I can’t tell you a date when this crisis will end but I can tell you we’re doing everything possible to have that day come sooner rather than later,” he said. On Thursday, one day before the G7 Summit of seven powerful nations, White House officials said the US would immediately commit $2 billion to the international effort known as Covax, which aims to help lower-income countries with vaccines. Mr Biden will pledge an additional $2 billion through 2021 and 2022 on condition that other countries fulfil their commitments. A third vaccine, from Johnson & Johnson, is administered in a single shot. The administration said on Wednesday that its use would probably be authorised by the Food & Drug Administration within a few days of a meeting on February 26 to consider the company’s application and clinical data. About 1.58 million shots per day were given in the US over the past week, according to the Bloomberg Vaccine Tracker, up from an average of roughly 900,000 per day in the week before Mr Biden took office. Supply is increasing as manufacturers increase production. Efforts led in part by the Biden administration to increase the number of people able to administer vaccines are also under way.