(Adam Glanzman/Bloomberg | Getty Images)The Trump administration is cancelling almost $500 million in contracts to develop mRNA vaccines to protect the nation against future viral threats. The move thrilled critics of the technology but horrified many public health and biosecurity experts. “That’s why we’re moving beyond the limitations of mRNA vaccines for respiratory viruses and investing in better solutions.”The announcement dismayed many who study infectious disease. She runs the Brown University School of Public Health Pandemic Center, and says the move could erode preparedness for future pandemics. Many experts say mRNA vaccines would provide a crucial deterrent and powerful defense against bioterrorists.