Washington, March 14 : The US administration has ordered "almost enough Covid-19 vaccine to fully inoculate every American adult twice," and its hoarding could fuel a vaccine gap worldwide, a media report said. US President Joe Biden announced on Wednesday that his administration will double the order of Johnson & Johnson Covid-19 vaccine to 200 million doses, which would bring the country's total vaccine order to 800 million doses, the Xinhua news agency reported on Saturday. The new order of the Johnson & Johnson vaccine "risks further exacerbating a vaccine gap between have and have-not nations," a media report said on Wednesday. The report added that Washington rejected Mexico's request on sharing vaccine doses, while the European Union "has made similar appeals." On Thursday, Biden announced that he will direct all states, tribes, and territories to make all adult Americans eligible for Covid-19 vaccines by May 1. "That doesn't mean everyone's going to have that shot immediately, but it means you'll be able to get in line beginning May 1," he said. Over 133 million vaccine doses have been distributed across the country as of Friday, said the US Centers for Disease Control and Prevention (CDC). Currently, there are about 35 million Americans fully vaccinated while nearly 66 million have received at least one dose, CDC data showed. /IANS