Dr. Anthony Fauci, the nation’s top infectious disease expert, says the recommended pause on the Johnson & Johnson Covid-19 vaccine is just that: a pause — and not a cancellation — and will likely last days to weeks.Dr. Anthony Fauci, the nation’s top infectious disease expert, says the recommended pause on the Johnson & Johnson Covid-19 vaccine is just that: a pause — and not a cancellation — and will likely last days to weeks.