Trucks hauling trailers loaded with suitcase–sized containers of Covid-19 vaccine rolled out of Pfizer’s manufacturing facility in Kalamazoo, Michigan, on Sunday – launching the largest and most complex vaccine distribution project in the US. The long-wished for development comes against a backdrop of a raging pandemic that has killed almost 300,000 Americans amid a botched government response by the Trump administration that has made the US the worst-hit country in the world. While progress on the vaccine is being celebrated across America, it also comes amid safety concerns and fears of anti-vaccination sentiments that might hinder the rollout. There are also worries over a potentially chaotic roll-out with local plans for vaccine distribution that vary widely, lack federal funding, and will not reach everyone even in early, limited populations. But despite those concerns the sight of trucks loaded with vaccines finally hitting the road at last cheered a nation beleaguered by its suffering at the hands of the virus. On Sunday morning an assembly line of workers had begun pulling doses out of a freezer, boxing the vaccine and loading the units onto pallets so they could be placed on trucks at the Pfizer plant. Dry ice, shipping labels and packing tape were on hand as the workers donning masks, face shields and gloves put together the packages inside the warehouse. US marshals will accompany the tightly secured shipments from factory to final destination after regulators authorised the vaccine from Pfizer and partner BioNTech for use. “We have spent months strategising with [federal] officials and our healthcare customers on efficient vaccine logistics, and the time has arrived to put the plan into action,” Wes Wheeler, the president of UPS Healthcare, said on Saturday. At the same time as distribution began, the Centers for Disease Control and Prevention director Robert Redfield accepted the recommendation of the agency’s Advisory Committee on Immunization Practices that the Pfizer vaccine may be given to people aged 16 and older. Initially, about 3m doses were expected to be sent out, and the priority is healthcare workers and nursing home residents as infections, hospitalizations and deaths soar in the US. With numbers likely to get worse over the holidays, the vaccine is offering a bright spot in the fight against the pandemic that has killed nearly 300,000 Americans. The New York times reported that officials at the White House – the site itself of multiple infections – would be among the first vaccine recipients, while Reuters quoted a source as saying Donald Trump, Mike Pence and other top officials would be offered the vaccine as part of a plan to ensure continuity of government. Essential personnel at the White House and certain officials in all three branches of government were to be vaccinated within the next 10 days, said the Reuters source. It was not immediately clear whether Trump would get the vaccine immediately, given he has already contracted the coronavirus. It was also not clear whether Joe Biden, Kamala Harris and other members of Biden’s transition team would be offered vaccinations. Federal officials say the first shipments of Pfizer’s vaccine will be staggered, arriving in 145 distribution centers Monday, with an additional 425 sites getting shipments Tuesday, and the remaining 66 on Wednesday. The vaccine, co-developed by German partner BioNTech, is being doled out based on each state’s adult population. Pennsylvania healthcare giant UPMC has chosen staff who are critical to operating its facilities as among those getting the first round of vaccinations, said Dr Graham Snyder, who led the center’s vaccine task force. “It’s very exciting. I will be thrilled, that moment when we administer our first dose,” Snyder said Saturday. “That will clearly be a watershed moment for us.” Snyder said the UPMC system estimates that half its employees are willing to get the vaccine as soon as it’s offered to them. Pfizer’s dry–ice cooled packages can hold as many as 4,875 doses, and the first leg of their journey will be from Kalamazoo to planes positioned nearby. Workers will load the vaccine – which must be kept at sub-arctic temperatures – onto the aircraft that will shuttle them to United Parcel Service or FedEx air cargo hubs in Louisville, Kentucky, and Memphis, Tennessee, respectively. From there, they will be trucked or flown to facilities close to the 145 US sites earmarked to receive the first doses. UPS and FedEx package delivery drivers, who may also be carrying holiday gifts and other parcels, will deliver many of the “suitcases” into the hands of healthcare providers on Monday. The shipments are the first of three expected this week. Courier companies are giving the vaccine top priority, reserving space on planes and trucks at a time when pandemic and holiday-related e-commerce are creating more demand for deliveries than carriers can handle. Both companies have expertise handling fragile medical products and are leaving little room for error. They are providing temperature and location tracking to backup devices embedded in the Pfizer boxes, and tracking each shipment throughout its journey. The Food and Drug Administration authorized emergency use of the vaccine Friday, saying it is highly protective and presents no major safety issues. While US regulators worked for months to emphasize the rigor and independence of their review, they faced political pressure until the final stages. Concerns that a shot was rushed out could undermine vaccination efforts in a country with deeply ingrained skepticism about vaccines. The head of the FDA said the agency’s decision was based on science, not politics, despite a White House threat to fire him if the vaccine wasn’t approved before Saturday. While the vaccine was determined to be safe, regulators in the UK are investigating several severe allergic reactions. The FDA’s instructions tell providers not give it to those with a known history of severe allergic reactions to any of its ingredients. Another vaccine by Moderna will be reviewed by an expert panel this week and soon afterward could be allowed for public use. There are fears though that concerns over the safety of vaccines might hamper their deployment. Top health expert Dr Anthony Fauci warned in an interview that he’s worried healthcare workers will decline to get vaccinated and that may discourage others from getting the vaccine also. “My primary biggest fear is that a substantial proportion of the people will be hesitant to get vaccinated,” Fauci said in an interview with the Daily Beast.