The mother's vaccine has been tested on 30,000 people, half received two doses of vaccine, half received a placebo.
According to the analysis, the vaccine should also have a good effect when it comes to counteracting serious covid-19 disease.
Of the 95 cases of coronary heart disease detected, 90 were in the placebo group.
In eleven cases, it was serious covid-19, all in the placebo group.
"Mild or mild side effects"
The side effects of the vaccine are described as mild or mild.
It is about pain when the vaccine is given, but also fatigue, headaches and muscle aches, according to Moderna's press release.
The result of the preliminary analysis means that the United States may have two possible vaccine candidates before the end of the year, the newspaper writes.
Modern data has not yet been published or externally reviewed through a so-called peer review.
Several vaccines are said to be effective
The announcement comes a week after the pharmaceutical giant Pfizer and its German partner BioNTech stated that their coronavirus vaccine is more than 90 percent effective.
Shortly after Pfizer announced the news, Russia's independent investment fund announced that the Russian vaccine Sputnik V is 92 percent effective.
The results of Modern and Pfizer must be reviewed by the US Food and Drug Administration (FDA) before their vaccine candidates are approved.
If they are approved by the FDA, the vaccine may be given to Americans who belong to the risk group already at the end of the year.