Would slowing the spread through measures give it more opportunities to accumulate mutations that help it break through immunity and vaccines? I'm somewhat worr

Would slowing the spread through measures give it more opportunities to accumulate mutations that help it break through immunity and vaccines? I'm somewhat worried prevention efforts led to delta. The virus would have naturally spread fairly quickly, and alternate universe delta would have had to adapt to reinfect people who already have immunity. The delta we have was selected to spread, and now it's facing populations with no immunity.