covid vaccines, vaccines covid, covid immunity, immunity covid, hybrid immunity covid, beta covid, covid delta, delta covid, delta herd immunity, covid herd immunity, herd immunity covid, herd immunity delta covid, covid19 vaccine, delta variant covid, covid vaccine delta, delta covid vaccine, covid-19 delta variant, pfizer covid, covid pfizer, moderna covid, covid moderna, pfizer vaccine covid, moderna vaccine covid, covid booster shot, booster shot covid
New research shows that some individuals mount immune responses even against variants.