related_tweet: @lilynus @campbelltn20 @tndeptofhealth @tnedu @tosstn1975 how can we possibly have herd immunity for covid-19 when:  1.) people can be re-infected with covid, 2.) spread is uncontrolled and creating new variants that are becoming more efficient at evading the vaccines, 3.) half of the  people in this country refuse to get vaccinated.