Encouraging news from today’s New York Times (Sorry, the formatting is a little wonky):

Why the vaccine news is better than you may think.

By David Leonhardt

Preparing the Pfizer vaccine in Phoenix.Adriana Zehbrauskas for The New York Times

‘We’re underselling the vaccine’
Early in the pandemic, many health experts — in the U.S. and around the world — decided that the public could not be trusted to hear the truth about masks. Instead, the experts spread a misleading message, discouraging the use of masks.

Their motivation was mostly good. It sprung from a concern that people would rush to buy high-grade medical masks, leaving too few for doctors and nurses. The experts were also unsure how much ordinary masks would help.

But the message was still a mistake.

It confused people. (If masks weren’t effective, why did doctors and nurses need them?) It delayed the widespread use of masks (even though there was good reason to believe they could help). And it damaged the credibility of public health experts.

“When people feel as though they may not be getting the full truth from the authorities, snake-oil sellers and price gougers have an easier time,” the sociologist Zeynep Tufekci wrote early last year.

Now a version of the mask story is repeating itself — this time involving the vaccines. Once again, the experts don’t seem to trust the public to hear the full truth.

This issue is important and complex enough that I’m going to make today’s newsletter a bit longer than usual. If you still have questions, don’t hesitate to email me at themorning@nytimes.com.

‘Ridiculously encouraging’
Right now, public discussion of the vaccines is full of warnings about their limitations: They’re not 100 percent effective. Even vaccinated people may be able to spread the virus. And people shouldn’t change their behavior once they get their shots.

These warnings have a basis in truth, just as it’s true that masks are imperfect. But the sum total of the warnings is misleading, as I heard from multiple doctors and epidemiologists last week.

“It’s driving me a little bit crazy,” Dr. Ashish Jha, dean of the Brown School of Public Health, told me.

“We’re underselling the vaccine,” Dr. Aaron Richterman, an infectious-disease specialist at the University of Pennsylvania, said.

“It’s going to save your life — that’s where the emphasis has to be right now,” Dr. Peter Hotez of the Baylor College of Medicine said.

The Moderna and Pfizer vaccines are “essentially 100 percent effective against serious disease,” Dr. Paul Offit, the director of the Vaccine Education Center at Children’s Hospital of Philadelphia, said. “It’s ridiculously encouraging.”

The details
Here’s my best attempt at summarizing what we know:

The Moderna and Pfizer vaccines — the only two approved in the U.S. — are among the best vaccines ever created, with effectiveness rates of about 95 percent after two doses. That’s on par with the vaccines for chickenpox and measles. And a vaccine doesn’t even need to be so effective to reduce cases sharply and crush a pandemic.

If anything, the 95 percent number understates the effectiveness, because it counts anyone who came down with a mild case of Covid-19 as a failure. But turning Covid into a typical flu — as the vaccines evidently did for most of the remaining 5 percent — is actually a success. Of the 32,000 people who received the Moderna or Pfizer vaccine in a research trial, do you want to guess how many contracted a severe Covid case? One.

Although no rigorous study has yet analyzed whether vaccinated people can spread the virus, it would be surprising if they did. “If there is an example of a vaccine in widespread clinical use that has this selective effect — prevents disease but not infection — I can’t think of one!” Dr. Paul Sax of Harvard has written in The New England Journal of Medicine. (And, no, exclamation points are not common in medical journals.)

On Twitter, Dr. Monica Gandhi of the University of California, San Francisco, argued: “Please be assured that YOU ARE SAFE after vaccine from what matters — disease and spreading.”

The risks for vaccinated people are still not zero, because almost nothing in the real world is zero risk. A tiny percentage of people may have allergic reactions. And I’ll be eager to see what the studies on post-vaccination spread eventually show. But the evidence so far suggests that the vaccines are akin to a cure

Offit told me we should be greeting them with the same enthusiasm that greeted the polio vaccine: “It should be this rallying cry.”

The costs of negativity
Why are many experts conveying a more negative message?

Again, their motivations are mostly good. As academic researchers, they are instinctively cautious, prone to emphasizing any uncertainty. Many may also be nervous that vaccinated people will stop wearing masks and social distancing, which in turn could cause unvaccinated people to stop as well. If that happens, deaths would soar even higher.

But the best way to persuade people to behave safely usually involves telling them the truth. “Not being completely open because you want to achieve some sort of behavioral public health goal — people will see through that eventually,” Richterman said. The current approach also feeds anti-vaccine skepticism and conspiracy theories.

After asking Richterman and others what a better public message might sound like, I was left thinking about something like this:

We should immediately be more aggressive about mask-wearing and social distancing because of the new virus variants. We should vaccinate people as rapidly as possible — which will require approving other Covid vaccines when the data justifies it.

People who have received both of their vaccine shots, and have waited until they take effect, will be able to do things that unvaccinated people cannot — like having meals together and hugging their grandchildren. But until the pandemic is defeated, all Americans should wear masks in public, help unvaccinated people stay safe and contribute to a shared national project of saving every possible life.