The platform, called AdVac, is also used in an Ebola vaccine approved earlier this year.
Johnson & Johnson executive committee vice-chairman and chief scientific officer Paul Stoffels said: "Combined with our own significant investment, this agreement has enabled our vital research and development and underscores the importance of public-private partnerships to tackle the worldwide Covid-19 pandemic".
She said: "For many, and in particular, black, Asian and ethnic minority communities, the word vaccine generates a lot of fear, rooted in mistrust, which can understandably lead to reluctance in taking part in a trial". He urged Americans not to let their guard down and to continue washing hands and being vigilant about social distancing.
The coronavirus pandemic in the US has entered perhaps its most risky phase.
He said more data was needed on the elderly "but this is definitely encouraging progress". This was a record high for the fourth consecutive day.
"Moderna have also announced that the vaccine can be kept in a conventional freezer (-20C) for up to six months, and that once thawed the vaccine can be kept for up to 30 days at standard refrigerator (2 to 8C)". Because of these temperature requirements, the company will ship vaccine doses in special temperature-controlled thermal boxes packed with dry ice.
A participant in Moderna's Covid-19 vaccine clinical trial receives a shot at Accel Research Sites in DeLand, Florida, on August 4. Of the 95 cases in Moderna's trial, 11 were severe and all 11 occurred among volunteers who got the placebo.
It says it's on track to manufacture between 500 million to a billion doses globally in 2021.
He said the next milestones for the vaccine will be the applications for Emergency Use Authorisation in the US, EU and elsewhere around the world in the coming weeks. Eleven cases of severe disease were reported in those who got the placebo.
Six thousand United Kingdom volunteers, some from the NHS Vaccines Registry, will take part in the studies at 17 National Institute for Health Research sites, including in Southampton, Bristol, Cardiff and London.
Saul Faust, professor of paediatric immunology and infectious diseases at the University of Southampton and University Hospital Southampton NHS Foundation Trust, said: "We just don't know how each of these vaccines is going to behave and which are going to generate the better short and long-term immunity".
Most after effects were mild to moderate, and generally short-lived, according to a company news release. When he learned the results later in the morning, the evidence that the vaccine prevented severe disease stood out as most consequential.
The Moderna vaccine, which was co-developed by the US National Institutes of Health, is given in two doses 28 days apart, and the preliminary results are based on the 95 of the 30,000 volunteers who fell ill with Covid-19.
The Trump Administration has mainly relied on the development of vaccines and treatments as its response to the pandemic.
"Our goal is to deliver more than 300 million doses by April next year, which could already have an impact", he said.
A key advantage of Moderna's vaccine is that it does not need ultra-cold storage like Pfizer's, making it easier to distribute.
Moderna also said it will use its data to seek authorisation in Europe and other regions.