Clinical journals are clear that the best way to determine if a medical treatment saves more lives than it takes is by measuring "all-cause mortality" in "randomized controlled trials." Such trials involving more than 70,000 people were conducted on the Moderna and Pfizer Covid mRNA vaccines, and they found no indication the vaccines save more people than they kill. More specifically, the trials found that neither of the vaccines decreased or increased the absolute risk of death by more than 0.08% over the course of the studies. However, the trials were limited in several respects (detailed at the link below), and the benefits and risks of these vaccines can vary greatly for each individual.