Americans will receive the first doses of Covid-19 vaccine on December 14, the day after Pfizer and its partners distributed the products across the country.

The first doses of the Pfizer-BioNTech vaccine will be delivered to 145 locations across the US on December 14.

The number of vaccines under the Rapid Campaign, an initiative of the President Donald Trump administration to accelerate the development and distribution of Covid-19 vaccine, will be delivered to all health centers in the US within three weeks,

Health care workers and the elderly in nursing homes will be given priority in the first 2.9 million doses of vaccine given in advance.

Despite months of preparation, distributing and vaccinating 330 million Americans remains a huge logistical challenge, added General Perna.

Pfizer is partnering with shipping companies such as UPS and FedEx to distribute vaccines with vaccination products such as cylinders, dry ice and protective medical equipment.

"The last route is the toughest. When vaccines reach hospitals and nursing homes, they have to be stored at the right temperature. The giant clock is running. There is no room for mistakes."

Pfizer's vaccine was approved urgently on December 11 amid a rising number of Covid-19 cases and deaths in the US in recent days while the emergency rooms showed signs of overcrowding.

Health regulators also reassured Americans that the emergency approval process took place at record speed but still guaranteed to be safe.

The FDA says Pfizer's vaccine is safe for most Americans with a history of allergy, despite reports of two cases of anaphylaxis with its vaccine in the UK.

The Trump administration has spent billions of dollars developing the Covid-19 vaccines and will be responsible for distribution to the states.

Britain became the first country to approve the Pfizer vaccine on December 2 and began the vaccination on December 8.