On Tuesday, it was announced that Dr Rick Bright (pictured) has been replaced as head of the HHS's Biomedical Advanced Research and Development Authority, or BARDA

The Trump administration has replaced the director of a key US agency that oversees the development of drugs, vaccines and diagnostics for the novel coronavirus.

On Tuesday, the US Department of Health and Human Services (HHS) announced it had removed Rick Bright as head of the Biomedical Advanced Research and Development Authority (BARDA).

Bright, an expert in vaccines and therapeutics, will be replaced by Gary Disbrow, his former deputy, who will serve as acting director, STAT News first reported.

However, the reasons for and circumstances surrounding his departure remain unclear.

BARDA was created in 2006 to aid drug and vaccine development projects for pandemics such as Ebola and Zika.

Bright joined BARDA in 2010 as its influenza and Emerging Infectious Diseases Division director before he became the lead in November 2016.

As the agency's director, he oversaw the development and procurement of therapeutics against infectious diseases.

Under his leadership, BARDA recently announced nearly $1 billion in support of vaccine manufacturing efforts by Moderna and Johnson & Johnson.

Gary Disbrow (left), Bright's former deputy, will serve as acting director of BARDA. The reason for Bright's departure is unclear but there are reports he had personal disputes with Trump administration officials including Bob Kadlec (right), the HHS Assistant Secretary for Preparedness and Response

Under Bright's leadership, BARDA announced nearly $1 billion in support of vaccine manufacturing efforts by Moderna and Johnson & Johnson. Pictured: A technician analyzes a rapid test COVID-19 nasal sample at UMass Memorial in Worcester, Massachusetts

Additionally, under the most recent stimulus package, Congress voted to more than triple BARDA's budget, reported STAT.

Bright will now be taking a narrower role at the National Institutes of Health (NIH) in the Accelerating COVID-19 Therapeutic Interventions and Vaccines partnership.

He will reportedly be working on speeding up the development of diagnostic tests in a public-private partnership announced last week between NIH and 16 pharmaceutical companies, an HHS spokeswoman said.

'Dr Rick Bright will transfer the skills he has applied as Director of BARDA to the National Institutes of Health, as part of a bold plan to accelerate the development and deployment of novel point-of-care testing platforms,' a statement read.

'Dr Bright brings extensive experience and expertise in facilitating powerful public-private partnerships that advance the health and well-being of the American people.'

No other details were provided regarding the circumstances of Bright's departure from BARDA.

But officials told BioCentury his leaving is the result of a personal fallout with several members of the Trump administation.

According to unnamed sources, STAT said Bright had personal disputes with Bob Kadlec, the HHS Assistant Secretary for Preparedness and Response, which oversees BARDA.

However, the nature of their disputes remains unclear.

Prior to working at BARDA, Bright worked for Centers for Disease Control and Prevention, with research focused on influenza viruses, antiviral drugs and tests, according to his public biography on the HHS website.

He has also served as an advisor to the World Health Organization and the United States Department of Defense.