A vaccine that survives a year without a freezer

MIT researchers have formulated RNA vaccines that stay stable at room temperature for up to a year, or at nearly 100 degrees Fahrenheit for two months, removing one of the biggest barriers to shipping them where cold-storage freezers do not exist. The work appears today in Nature Biotechnology. Standard mRNA vaccines have to be kept between -20 and -80 degrees Celsius. To get around that, the team tweaked the formulation around the lipid nanoparticles that carry the RNA, testing FDA-approved excipients with help from a machine-learning algorithm. For months, nothing worked. "It was really frustrating for the team," said Ana Jaklenec, a principal investigator at MIT's Koch Institute. The algorithm converged on a stable recipe in a handful of iterations rather than thousands of experiments. Mice given the heat-resistant Covid-19 vaccine, even after long storage, mounted an immune response equal to a Moderna-like shot. The same formulation also worked as a dissolving microneedle skin patch. The research was funded in part by the Gates Foundation.