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Cathy O’Neil is a Bloomberg Opinion columnist. She is a mathematician who has worked as a professor, hedge-fund analyst and data scientist.

The battle lines in the war on COVID-19 have been getting blurrier, as infections surge and studies offer changing and sometimes conflicting data on exactly how much protection vaccines provide. Amid the fog, we mustn’t lose sight of a crucial truth: Vaccines still work, and they’re still a miracle.

Not long ago, the goal seemed clear: If enough people achieved immunity through vaccination or infection, the pandemic would peter out for lack of targets. Now that “herd immunity” seems ever more distant. The delta variant’s enhanced transmissibility has raised the bar. The virus still roams freely in places with low vaccination rates. Isolation-weary people are heading out and taking their chances. As school restarts and new variants emerge, the situation is likely to get worse.

Meanwhile, the most crucial data points about vaccines — how well they protect against hospitalization and death — are in flux. Early in the vaccination drive, the chances of an inoculated person dying of COVID-19 appeared to be about one in a million. Delta has probably driven that up somewhat, but a dearth of adequate information makes it difficult to say by how much.

News stories tend to freak people out by focusing on “breakthrough cases,” in which people get COVID despite vaccines. Most official data cover the whole period since vaccinations began, so they obscure the more recent effect of delta. Just looking at the share of vaccinated among the hospitalized and dead isn’t great, either: If everyone were vaccinated, it would be 100 percent.

In the absence of good data, the message about vaccines keeps getting foggier. The information that filters through often ends up providing fodder for anti-vaxxers. What people hear is, don’t bother getting vaccinated because you can still get COVID and even die.

What’s needed is a reporting system that would allow the Centers for Disease Control and Prevention to calculate COVID-related hospitalization and death rates among the vaccinated and the unvaccinated on a regular basis, at the state and national level. With, say, weekly or even daily reporting on cases per 100,000 people, it would be much easier to see whether and by how much delta and other emerging variants were actually wearing down the vaccines’ most important protections.

One recent study done in Los Angeles County, California, offers a glimpse of what such reporting might show. Looking at cases from May 1 through July 25, when delta was already circulating, it found that unvaccinated people were 29 times more likely than vaccinated people to end up in the hospital with COVID-19 infections.

So vaccines are still effective, miraculously so. Getting inoculated can save your life, and certainly justifies living more like normal. The message needs to get through.