The human trials for the U.S. COVID-19 vaccine from Moderna Therapeutics started on Monday.  According to the Online Citizen:

The first participant in a clinical trial for a COVID-19 vaccine will receive the experimental vaccine on Monday (16 March), a United States (US) government official said.

The official also spoke on the condition of anonymity as the trial has not been publicly announced yet, according to an AP report earlier today. The National Institutes of Health (NIH) is funding the trial which will take place at the Kaiser Permanente Washington Health Research Institute in Seattle.

The trial is aimed to test whether the vaccine will show any potential side effects and to set the stage for a larger test. It will start with 45 young and healthy volunteers, in which they will be given different doses of shots co-developed by NIH and Moderna Inc.

Originally, according to Time, NIH was planning to delay the start of its human trials until April, at the earliest, even though it had received the vaccine from Moderna in February:

Moderna Therapeutics, a biotech company based in Cambridge, Mass., has shipped the first batches of its COVID-19 vaccine. The vaccine was created just 42 days after the genetic sequence of the COVID-19 virus, called SARS-CoV-2, was released by Chinese researchers in mid-January. The first vials were sent to the National Institute of Allergy and Infectious Diseases (NIAID), part of the National Institutes of Health (NIH) in Bethesda, MD, which will ready the vaccine for human testing as early as April.

My guess is that the Trump administration is now intervening to get NIH to stop slow-walking the U.S. vaccine.  Israelis have claimed that they can get their COVID-19 vaccine through their regulatory process in just three months, but NIH officials have repeatedly told the press that no COVID-19 vaccine could possibly get through their procedures in less than a year.