J&J (JNJ) COVID-19 Booster Jab Compares Well With Comirnaty Posted byZacks Equity Research December 6, 2021 Leave a comment on J&J (JNJ) COVID-19 Booster Jab Compares Well With Comirnaty Booster dose of J&J’s (JNJ) COVID-19 vaccine elicits comparable neutralizing activity and higher T-cell responses in previously-vaccinated persons with Comirnaty.