As the coronavirus spreads among the unvaccinated, it mutates into different variants. The latest seems to be the "Mu" variant, steadily holding at about 1% to 3% of the hospital cases since July of 2021.
The Delta variant seems to be the dominant strain, at about 97% or more of all hospital cases.
The Pfizer, Moderna, and J&J vaccines seem to be effective against the new variants.
Stop worrying and get vaccinated.