My battery is only 8 months old and after installing the latest release of IOS, my battery health is seriously degraded.

What does seriously degraded mean? When you go to Settings > Battery > What is the Battery Health listed?

Batter Health usually drops from 100% to 80% in two years, and not always in a nice linear pattern. It could be 100% for 18 months then suddenly decide to re-calibrate and discover the gap and drop to 85%. If you are on a 1% per month line, it is normal.

If you saw a sudden drop in Battery Health after it remaining the same for some time, that's not unusual. But you didn't indicate what numbers you saw, so it's a bit difficult to determine if it's unusual or in line with expectations.