Effectiveness of a fourth dose of mRNA COVID-19 vaccine against all-cause mortality in long-term care facility residents and in the oldest old: A nationwide, retrospective cohort study in Sweden - The Lancet
Safety of the fourth COVID-19 BNT162b2 mRNA (second booster) vaccine: a prospective and retrospective cohort study - The Lancet Respiratory Medicine
Get Your 4th and 5th COVID Booster Shot NSW at HHMP
Vaccines | Free Full-Text | The Four Ws of the Fourth Dose COVID-19 Vaccines: Why, Who, When and What
Efficacy of a Fourth Dose of Covid-19 mRNA Vaccine against Omicron | NEJM
U.S. officials authorize 4th dose of Pfizer COVID-19 shot for Americans 50 and up | CBC News
Pfizer Asks US to Allow 4th COVID Vaccine Dose for Seniors
Israeli study shows 4th shot of COVID-19 vaccine less effective on Omicron | Reuters