How long-term Covid-19 immunity paves the way for universal Covid-19 vaccines

In recent months, scientists have also learned that the immune cells that provide lasting protection — known as memory B cells and T cells — can keep the worst effects of the most recent versions of the virus at bay, even if they were trained to corral older strains of SARS-CoV-2. Vaccine researchers are expanding their focus from antibodies to these memory immune cells as the new discoveries open a path toward universal coronavirus vaccines. Universal vaccines, however, are still a long way off — possibly years — drawing on approaches never used before. “That’s a scientific challenge,” said Anthony Fauci, chief medical adviser to the president, during the summit.