However, the cost of the Moderna vaccine is much higher than that of Pfizer.
Millions of doses of the Moderna vaccine are expected to be added to the United States rollout, which began this week with healthcare workers. The second group to receive COVID 19 vaccine will be persons, over 50 years of age and persons under 50 years with comorbid conditions.
The COVID-19 vaccine developed by pharmaceutical giant Pfizer and German firm BioNTech was approved by the US Food and Drug Administration on 11 December.
Both are given in two doses; Pfizer's 21 days apart and Moderna's 28 days apart. While the vaccine needs to be shipped and stored frozen, unlike the BioNTech-Pfizer shot, it does not have to be kept at ultra-cold temperatures.
While the vaccines have not been compared head-to-head, Moderna's vaccine appears to be associated with slightly more severe cases of fatigue, headache and fever in the day or two following the second shot, especially in people younger than 65.
The United States, which has a population of some 330 million, is expected to have enough doses to vaccinate 20 million people by the end of the year, according to the government.
Russian Federation implicated in massive cyber-attacks on American government agencies
That was because customers of SolarWinds network monitoring tools include many branches of the United States government. In an update Thursday , the U.S.
The FDA decision marks the first regulatory authorisation in the world for Moderna's vaccine and validation of its messenger RNA technology, shown to be almost 95 per cent effective with no serious safety concerns.
"Brighter days lie ahead", responded US President-elect Joe Biden, who plans to be vaccinated on Monday.
Surgeon General Jerome Adams has spoken with people of color in the United States and said they become emotional when discussing their hesitancy in getting the Covid-19 vaccine over government mistrust.
U.S. President Donald Trump on Twitter hailed the authorization. The vaccine must be transported to hospitals and other centre before injections begin. Pfizer and Moderna each say they're on track to deliver 100 million doses by the end of the first quarter.
A second vaccine represents a ray of hope amid despair as the virus continues to spread unabated across the USA even before holiday gatherings that are certain to further fuel the outbreak.
Even with two highly effective vaccines, practices such as social distancing and face covering will be needed for months before enough people are inoculated to curb virus transmission and eventually end the pandemic.