• Original Reporting
  • Sources Cited
Original Reporting This article contains new, firsthand information uncovered by its reporter(s). This includes directly interviewing sources and research / analysis of primary source documents.
Sources Cited As a news piece, this article cites verifiable, third-party sources which have all been thoroughly fact-checked and deemed credible by the Newsroom in accordance with the Civil Constitution.
A coronavirus piñata at a vaccine event in Henderson on Feb. 26, 2021. (Jesse Paul, The Colorado Sun)

So, at long last, you’ve managed to book a coronavirus vaccination appointment for yourself — hooray! — only to discover that you will be receiving the new vaccine made by Johnson & Johnson.

You’ve seen the headlines saying that particular vaccine is less effective than the ones made by Pfizer or Moderna. Perhaps you’ve heard stories from around the country of people — including the mayor of Detroit — not wanting it because they’re holding out for what they believe are better options.

And now you’re thinking to yourself: Is this a good idea? Am I about to get a junior-varsity vaccine?

Well, Colorado health leaders want to put your mind at ease. Say goodbye to your vaccine FOMO and get that shot. Here’s why:

It might not actually be less effective

Let’s start with the basics on the Johnson & Johnson vaccine. (It’s also called the Janssen vaccine, for the Johnson & Johnson subsidiary that developed it, but almost everybody shorthands it as the J&J vaccine, so we’ll use that.)


The latest from the coronavirus outbreak in Colorado:

  • MAP: Cases and deaths in Colorado.
  • TESTINGHere’s where to find a community testing site. The state is now encouraging anyone with symptoms to get tested.
  • VACCINE HOTLINE: Get up-to-date information.


The J&J vaccine has a big technological difference from the Pfizer and Moderna vaccines — it’s on a different vaccine “platform,” in the same way that Apple and Samsung phones use different operating systems to both, you know, put Facebook in your pocket.

All the vaccines train your immune system to recognize the coronavirus’ distinct “spike” protein. The Pfizer and Moderna vaccines do this by sending instructions for how to make the spike protein (and only the spike protein, which is harmless on its own) to your cells via little bits of messenger RNA. Your body then makes the sparring partners for your immune system.

The J&J vaccine builds the spike proteins onto a virus that is harmless to humans, called an adenovirus, and then injects that dummy into your body for your immune system to practice against. So, same goal, just a different way of doing it.

In clinical trials, the vaccines from Pfizer and Moderna both showed efficacy rates of above 90%. During its clinical trials, the Johnson & Johnson vaccine showed a worldwide efficacy rate of 66%, with a 72% efficacy rate in the United States.

But Dr. Thomas Jaenisch, an epidemiologist and professor at the Colorado School of Public Health, said you can’t directly compare the performance number. Why? Because the trials were conducted at different times.

The J&J trial occurred later and encountered more coronavirus variants that might be better at evading all vaccines. So there’s no way to say how the Pfizer and Moderna vaccines would have fared in trials run at the same time as J&J’s.

“It was tested … under more difficult conditions compared to the two other candidates,” Jaenisch said. “This might have contributed to the fact that they have higher efficacies.”

Deanne Kahler, a registered nurse at Lincoln Community Hospital in Hugo, handles a Moderna COVID-19 vaccine vial before the start of a vaccination clinic on Feb. 24. (Andy Colwell, Special to The Colorado Sun)

Also, you’re looking at the wrong number

Regardless of the trials’ timing, health experts say the overall efficacy number is not really the one to look at. That number measures how well the vaccine does at preventing you from getting even moderately sick.

That’s a worthy goal; no one likes to be sick. But the most important thing for a vaccine to do is to prevent you from getting really sick — sick enough to be hospitalized or maybe even killed. And, by that measurement, all three vaccines perform exceptionally well.

J&J’s clinical trial had roughly 9,000 people in the United States who received the vaccine. A few were infected shortly after getting the shot and developed COVID-19 before the vaccine had time to work. But of those who made it  28 days without getting sick, only one person went on to develop severe COVID-19.

Statisticians calculated the vaccine’s efficacy of preventing severe to critical COVID-19 at 86% in the U.S. None of the trial participants across the globe who received the vaccine died of COVID-19.

Similar results were reported for the Moderna vaccine, with zero severe COVID-19 cases, and the Pfizer vaccine, with one severe case, though both drew from larger pools in this analysis.

J&J’s vaccine was also shown to be highly effective at preventing severe illness in South Africa and in Brazil, two countries where worrisome variants are rampant.

“It’s been very effective to what’s most important, which is protecting (against) severe disease,” said Dr. Eric France, the chief medical officer of the Colorado Department of Public Health and Environment.

It works faster

The people in charge of vaccine distribution logistics are pumped for the J&J vaccine because it is so much easier to store and administer. Unlike the Moderna and Pfizer vaccines, which require regular and ultracold freezers, J&J can be stored in a refrigerator.

It’s also only one shot, compared to the two doses needed of the other vaccines. And while the logistics folks like the simplicity, this also has an advantage for the recipient. You reach full immunity faster.

Right now, if you get the Moderna or Pfizer vaccines, you are looking at a six-week period before you are fully immunized and ready to hit the town. With J&J, you can be out socializing maskless with other vaccinated people, in keeping with new federal guidance, in two weeks.

“It’s amazing what Johnson & Johnson can do with only one shot,” Jaenisch said.

The sooner you get any vaccine, the better

Dr. Steve Groshong, right, administers the Pfizer-BioNTech COVID-19 vaccine to Jeffrey Fossum during a drive-through vaccine clinic in the parking lot at National Jewish Health on Jan. 29 in Denver. (Kathryn Scott, Special to The Colorado Sun)

When global health leaders many months ago set the target for coronavirus vaccine efficacy, they didn’t have high hopes. The World Health Organization put the minimum target at 50% for preventing moderate illness. And this wasn’t an unusual goal — flu vaccine effectiveness usually hovers somewhere around 40% to 60% for preventing illness.

To have three coronavirus vaccines to vastly exceed that has been near-miraculous to health experts, like back-to-back-to-back home runs.

“Most of the people I know, me included, would have thought that the first vaccines to come out would not have such high efficacy numbers,” Jaenisch said.

But, meanwhile, the virus is still out there. The faster-spreading variants lurk. There’s an urgent need to build immunity across the population.

So here’s the most common argument state leaders make when it comes to whether to get Pfizer or Moderna or J&J: Now is better than later.

“When you’re up, get vaccinated. Don’t think twice,” Gov. Jared Polis said.

“The best vaccine,” Jaenisch said, “is the one you can get soon.”

This is probably not the only time you’ll get a coronavirus vaccine

There’s one more point that health experts make, and it’s a bit of a bummer: Think of this not as your only coronavirus vaccine but as your first coronavirus vaccine.

Work has already begun to update the vaccines to better protect against the current variants. More new variants might emerge. Researchers are still trying to understand how long immunity from the vaccines will last.

All this leads Jaenisch and others to conclude that people will likely need booster shots or vaccine updates in the future. And that takes a bit of the pressure off which vaccine you receive now. It’s not the one you’re stuck with for life.

So Jaenisch encourages people to embrace the good news here.

“We have pretty powerful tools now,” he said. “It’s amazing, after just one year.”

Dr. Steve Groshong, administers the Pfizer-BioNTech COVID-19 vaccine to Janeen Webber during a drive-through vaccine clinic in the parking lot at National Jewish Health on Jan. 29 in Denver. (Kathryn Scott, Special to The Colorado Sun)

John Ingold is a co-founder of The Colorado Sun and a reporter currently specializing in health care coverage. Born and raised in Colorado Springs, John spent 18 years working at The Denver Post. Prior to that, he held internships at...