US President Donald Trump has said that his administration is confident the United States will have a vaccine for Covid-19 by the end of this year.
Mr Trump said he is not concerned about which country develops a vaccine first but just want to get a vaccine that works.
Public health officials have said a coronavirus vaccine could take a year to 18 months. Vaccines often take many years to develop and distribute.
According to media reports, there are 14 potential vaccines for COVID-19 under development as part of the effort to fast-track vaccine development.