We asked experts about how the technology works, its safety and its potential in medicine. Health Secretary Robert F. Kennedy Jr. has repeatedly questioned the safety of mRNA vaccines against Covid-19. Scientists with funding from the National Institutes of Health were advised to scrub their grants of any reference to mRNA. Around the country, state legislatures are considering bills to ban or limit such vaccines, with one describing them as weapons of mass destruction.
While mRNA, or messenger RNA, has received widespread attention in recent years, scientists first discovered it in 1961. They have been studying it and exploring its promise in preventing infectious diseases and treating cancer and rare diseases ever since.
What is mRNA?
A large molecule found in all of our cells, mRNA is used to make every protein that our DNA directs our bodies to build. It does so by carrying information from DNA in the nucleus out to a cell’s protein-making machinery. A single mRNA molecule can be used to make many copies of a protein, but it is naturally programmed to die eventually, said Jeff Coller, a professor of RNA biology and therapeutics at Johns Hopkins University and a co-founder of an RNA therapeutics company.