Stop and reflect on the success of the coronavirus vaccines. While most vaccines take five to 10 years to develop and manufacture, the remarkable mRNA shots appeared in less than a year. They were safe, efficacious, free and dramatically reduced serious illness and death, one of the great biomedical achievements of all time.

Yet their results could have been even better.

A study from Oliver Watson and colleagues at the MRC Centre for Global Infectious Disease Analysis at Imperial College London, which was published in the Lancet, sheds light on the scope of the achievement. Using mathematical modeling to examine 185 countries and territories, the scientists found that the coronavirus vaccines saved 19.8 million lives in the first year of vaccination, starting Dec. 8, 2020. This is based on a broad definition of pandemic suffering, the estimated excess death toll, and amounts to averting an astounding 63% of all deaths – in other words, cutting the loss by more than half. By a narrower definition of pandemic suffering – officially-reported deaths – coronavirus vaccines prevented 14.4 million deaths, or 79%. A separate study published earlier, consistent with the latest one, showed that vaccines prevented about 1.1 million deaths in the United States in the first year.

It could have been better.

If the World Health Organization’s global target of a vaccination rate of 40% of all populations by the end of 2021 had been met, it would have averted nearly 600,000 additional deaths, the study said, the majority in poorer countries. In the United States, the vaccine success was tempered by the refusal of millions to accept the shots. Overall, 71% of the eligible U.S. population is fully vaccinated with two shots, but only 49% of those eligible have gotten a first booster dose. Even fewer, 26% of the eligible population have a second booster. In all age groups, the total uptake of these remarkable lifesaving vaccines fell far below the number eligible, and many of those who refused paid a high price. The Centers for Disease Control and Prevention said that, in April, people over 50 years old who were unvaccinated had 42 times the risk of dying from COVID-19 as those with all the shots, including two boosters. The tragedy is that so much hesitancy was caused by the deliberate spread of disinformation from anti-vaccine campaigners.

In a deeply unsettling move, anti-vaccine campaigners in Ohio are organizing a ballot initiative on a proposal that would effectively block vaccine mandates. An independent, nonprofit news organization, the Ohio Capital Journal, said the provision declares: “An individual’s right to refuse any medical procedure, treatment, injection, vaccine, prophylactic, pharmaceutical or medical device shall be absolute.” If approved by referendum, this would be written into the state’s constitution, making Ohio the only state with such a provision – though whether it would violate the U.S. Constitution might be in question.

COVID and other diseases are not one person’s problem alone. They can transmit and spread. An unvaccinated person endangers others – and entirely unnecessarily, with highly effective and safe vaccines at hand.