Researchers hunt for clues in our blood to discover COVID-19 vaccines of the future

As these vaccines near the finish line, scientists will face a predicament: Successful authorization of the first vaccines will make it difficult, if not impossible, to continue to study COVID-19 vaccines of the future. Now, a group of researchers say they are zeroing in on a possible solution. By studying monkeys, they say they've identified a clue in our immune systems -- a signature that could show if a vaccine is working. If their results pan out in humans, the findings could help researchers side-step the need for massive, phase 3, placebo-controlled clinical trials, like the ones that are being conducted today for the current COVID-19 vaccines.