It took only 8 months because covid has been in existence for decades. Covid 19 strain was new and the vaccines had to be adjusted to new strains not created from ground up
Not so; the mRNA technology used to develop and deliver the vaccine has been in progress for decades. The hardest parts were done before SARS-CoV-2 ever existed, but it's wrong to claim that "the vaccines" needed to be tweaked - they never existed.
For people confused about this, there were prior commercial attempts at coronavirus vaccines, with mixed success. They were not RNA vaccines. The COVID-19 vaccines built on that research (regarding what proteins to target, in particular), but the COVID vaccines that were rolled out were completely novel technology.