Aug 5 (Reuters) - The U.S. Department of Health and

Human Services said on Tuesday it would wind down mRNA vaccine

development activities under its biomedical research unit.

The unit, Biomedical Advanced Research and Development

Authority, helps companies develop medical supplies to address

public health threats, and had also provided billions of dollars

for development of COVID-19 vaccines during the pandemic.

HHS said the wind down includes cancellation of a

contract awarded to Moderna ( MRNA ) for the late-stage

development of its bird flu vaccine for humans and the right to

purchase the shots, a move first reported in May.

The U.S. health agency said it is also rejecting or

canceling multiple pre-award solicitations, including proposals

from Pfizer ( PFE ), Sanofi Pasteur, CSL Seqirus

, Gritstone and others.

In total, this affects 22 projects worth nearly $500

million, the agency said.

HHS said the decision follows a comprehensive review of

mRNA-related investments initiated during the COVID-19 public

health emergency.