Scientists are learning why vaccines are working against new COVID variants.

We know vaccines are working against new COVID variants. Now scientists are starting to understand why. Since the emergence of new COVID-19 variants, experts have worried that the virus may have developed mutations allowing it to outmaneuver existing vaccines. Early laboratory studies proved worrisome, showing vaccines seemed to produce far fewer virus-fighting antibodies against some of the newer variants. Now, after months of research, vaccine experts across the globe are learning that vaccines still mostly work -- even when those antibodies fail to show up in great numbers -- thanks to other crucial parts of the body's immune system. DR. ONYEMA OKOLO YahooNews

Since the emergence of new COVID-19 variants, experts have worried that the virus may have developed mutations allowing it to outmaneuver existing vaccines.

Early laboratory studies proved worrisome, showing vaccines seemed to produce far fewer virus-fighting antibodies against some of the newer variants. But real-world experience didn't match those concerns -- people seemed to develop good protection, even when exposed to new variants.

Now, after months of research, vaccine experts across the globe are learning that vaccines still mostly work -- even when those antibodies fail to show up in great numbers -- thanks to other crucial parts of the body's immune system.

" One of the reasons why the vaccines are holding up against variants is they do raise a broad array of immune responses," said Dr. Dan Barouch, director of the Center for Virology and Vaccine Research at Beth Israel Deaconess Medical Center. "We speculate that multiple immune parameters may contribute to the protection observed by this vaccine against variants."

In a recent study, Barouch and some colleagues showed that the Johnson & Johnson vaccine prompted all different parts of the immune system to react. Crucially, the study helped reinforce the importance of so-called "killer" T-cells in defending against viral variants, including the worrisome "Beta" variant first identified in South America.

"Killer T-cells are important because they can actually identify an infected cell and get rid of it, and so they're very good at mopping up infection," Dr. Paul Goepfert, a professor of medicine at the University of Alabama at Birmingham and an expert in vaccine design.

The body's ability to harness multiple parts of the immune system following immunization against the original strain of COVID-19 is still leading to robust protection against multiple variants. ...