Like other viruses, the virus that causes COVID-19 changes over time. And, just like other vaccines and boosters, doctors and researchers are continually working to improve COVID-19 vaccines.
The FDA authorized two bivalent boosters – one by Moderna and the other by Pfizer – that are specifically formulated to protect against COVID subvariants, BA.4 and BA.5, and their sublineages, in addition to the original strain of COVID.
COVID-19 vaccines and boosters are critical to providing ongoing protection as immunity wanes and the virus continues to mutate.
Please check with your doctor if you have further concerns.
Source: https://www.fda.gov/emergency-preparedness-and-response/coronavirus-disease-2019-covid-19/covid-19-bivalent-vaccine-boosters (FDA)