There are also some concerns that the Delta variant picked up an additional mutation that helps it circumvent vaccines. (And even if it didn’t happen yet, with many people already vaccinated but Delta cases growing rapidly in many places, it’s just a matter of time until virus evolution gets there. But there are booster shots being tested already.)
There are also some concerns that the Delta variant picked up an additional mutation that helps it circumvent vaccines. (And even if it didn’t happen yet, with many people already vaccinated but Delta cases growing rapidly in many places, it’s just a matter of time until virus evolution gets there. But there are booster shots being tested already.)