(CNN) Vaccine advisers to the US Food and Drug Administration start meeting early Friday to discuss whether Americans need booster shots yet. It could affect how people view vaccines, and for many, it taps into fears about disease and unknown risks. But the questions the FDA's Vaccine and Related Biological Products Advisory Committee will be considering are straightforward: Is immunity waning, and will boosters restore it? Levels of these immune system proteins -- the first line of defense against infection -- spike after people get a booster dose. As with other vaccines that require boosters, a longer interval of time between initial immunization and the booster seems to amplify this response.

Source: CNN September 17, 2021 00:22 UTC