On Wednesday, US President Donald Trump posted a tweet in which he said there was "great news about vaccines."
Trump's change coincides with the announcement by the team of researchers conducting a study of the Moderna vaccine against Corona virus, that the serum is safe, and they confirmed that it stimulated immune responses in the body of all volunteers in the first stage of the experiments.
The American pharmaceutical company, Moderna, announced yesterday that the clinical trials of its Covid-19 pandemic vaccine will enter the final stage on July 27, in an effort to know the effectiveness of this vaccine in protecting people from infection.
If successful, this vaccine, which is considered one of the most prominent candidates on the list of US President Donald Trump's administration, could become a turning point for Moderna, which is based in Cambridge, Massachusetts, and which had no licensed product at all.
Moderna is at the forefront of the global race to reach the anti-pandemic vaccine, which has so far infected more than 13 million people in the world and caused more than 570,000 deaths.
Scientists warn that the first vaccines to be released on the market will not necessarily be the most effective.
And a group of countries are competing globally to produce the first successful vaccine against the emerging Corona virus, whose pandemic has killed about 570,000 people.