The influenza pandemic of 1918-’19 is the worst infectious-disease outbreak in American history.

First identified among military personnel in Europe, it quickly spread around the globe, showing up in American army camps by the summer of 1918. It spread quickly: In less than a week after the first case was reported at Camp Devens in Massachusetts, there were 6,674 cases.

Infection often led to pneumonia. Death typically came within two days after the first symptoms were noticed. Subsequent waves of infections occurred during the following winter and the spring of 1919.

When it was all over, the virus caused an estimated 25 million deaths worldwide and 675,000 in the United States. It’s a record that still stands today,  more than a century later.

But we are about to see it eclipsed. As of this writing, 656,000 deaths have been attributed to COVID in the U.S. in 2020 and 2021, and we are averaging more than 1,500 deaths every day. At this rate, we will pass the death toll of the flu pandemic by Sept. 22.

The world is very different today than during the influenza pandemic.

For one thing, the influenza deaths need to be put in context of the nation’s population. The United States of 1918-19 had about one third as many people as the country has today, so the earlier pandemic had a much higher death rate. The 675,000 deaths represented 0.6 percent of the population in 1919, while that total would represent only 0.2 percent today.

But other differences need to be taken into account.

Most importantly, there was no influenza vaccine in 1918 to stop the spread of the virus. We have a COVID vaccine, and it works. According to one of three studies released Friday by the federal Centers for Disease Control and Prevention, people who were not fully vaccinated against COVID were 10 times more likely to be hospitalized and 11 times more likely to die than those who had received their shots. The approved vaccines were 86 percent effective in preventing hospitalization, even with the highly delta variant, another study released by the CDC found.

And today’s COVID patients have the benefit of more than 100 years of advances in medical science as well as the ability of public health officials to communicate to every corner of the country simultaneously, getting potentially life-saving information to people in real time.

The death rate should be lower today than it was at the time of the First World War. It should be even lower than it is.

Unfortunately, too many modern Americans are dying of COVID, despite all of our advantages.

The vaccines have become politicized, with influential Americans discouraging others from taking advantage of the protections they provide. Two-thirds of Mainers are fully vaccinated, but nationally the number is just over half, giving the virus too much opportunity to spread and mutate.

That’s why we needed the Biden administration’s actions last week to require all federal employees and contractors as well as the employees of large businesses to get vaccinated or submit to weekly testing.

The more people get the vaccine, the less we will have to worry about COVID. It seems unlikely that we can avoid passing the 1918-19 influenza pandemic as the deadliest pandemic in history, but we have to tools to stop people from dying, if we choose to use them.