I got the Pfizer Covid-19 vaccine. Or maybe not.

When I volunteered to roll up my sleeve for an unproven Covid-19 vaccine, I was nervous. Not so much about the vaccine — I’d done my research and felt satisfied it was safe enough. What made me nervous was telling my friends and family. How would they respond to learning I was going to be a guinea pig?

If they balked, I had my rationales ready. First, the professional reason: As a science journalist, I’ve heralded the benefits of biomedical research in stories about vaccines and clinical trials. If I believed in what I was writing, shouldn’t I be willing to put my own body forward?

Then, the selfless one: I wanted to help, to know that I was doing everything possible to get us past this pandemic.

And let’s not forget the selfish reason: If  this vaccine works, and if  I received the real thing and not the placebo (I had a 50/50 chance), then I’d be one of the first to join the herd, immune to the scourge. That reasoning got a boost Monday, when Pfizer announced the vaccine I might have received was more than 90 percent effective.

There’s no way to work this kind of announcement casually into conversation, but I managed to share it with a few people — and heard nothing but praise. “That’s cool,” my mom said. And when I told an editor I wouldn’t be available one morning because I was going to be in the experiment, she just said, “Thanks for taking one for the team.”

True, my personal circle is inhabited by a high number of science PhDs (we’re super fun, I promise!). And I know not everyone thinks the way we do. A mid-October poll reported that only 58 percent of Americans said they would get a Covid-19 jab as soon as one is approved and ready. For Black Americans, the figure was just 43 percent.

But to ensure a vaccine is safe and effective for all, it has to be tested on volunteers of diverse backgrounds and ages.

There are multiple potential Covid vaccines in large-scale trials around the world, and each requires thousands of raised hands. I’m not going to say you should be in a trial; that’s a highly personal decision. But if you’re so inclined? Thanks for taking one for the team.

Vaccines and clinical trials have gotten a bad rap, and in some cases, it’s been justified. People of color have valid historical reasons to distrust doctors wielding experimental treatments, and medicine has a long record of under-including minorities in clinical trials.

In the current crisis, we’ve watched the US Food and Drug Administration giddily rush to approve treatments based on scant data, then backtrack later. Some people are worried that vaccines, too, will be rushed to citizens before safety is certain.

So I did my research. Thanks to an article I wrote over the summer, I had a good idea of what was in the shot I might be getting. If I got the real thing, it’d be genetic material (RNA) encoding a part of the virus — which should, it’s hoped, train my immune system to attack the virus behind Covid-19 itself.

I wanted to know how many people had received the vaccine already, and what happened to them. I found my answer on MedRxiv, a collection of not-yet-vetted scientific articles. At least three dozen people had received this particular candidate vaccine, according to an article that’s since come out in the peer-approved scientific literature, and some of them experienced side effects like fever and chills, headaches and fatigue. I could handle all that.

Over the phone, I peppered a nurse with further queries. If the shot made me sick, would Pfizer cover my medical bills? Yes. If this or some other Covid vaccine became widely available in the future, would trial participants be allowed to get it? Again, yes.

So in early September, I drove 15 miles — farther than I’d traveled in months — to a clinic in Long Beach, California, that overflowed with fellow volunteers being shepherded to and fro by harried nurses trying to maintain social distancing. I was heartened to see Black and Hispanic faces. I didn’t get a chance to compare notes with any of them, so I’ll never know why they chose to participate or how their families reacted.

The shot itself was almost anticlimactic. I felt barely a pinch.

Having promised to return for a booster and several checkups, I headed home with a phone number to call 24/7 if I had any problems, a smartphone app to report any Covid symptoms, and a prepaid credit card loaded with $119 for my trouble. (The card received two more deposits for the visits that followed, but I haven’t used any of the money to avoid a conflict of interest as a science journalist.) I imagined those magic RNAs seeping through my muscle, sneaking into my cells and setting up shop to prime my system against a Covid invasion.

Of course, I could have just gotten an armful of saltwater. I knew from my research that, among the small group of early participants, those who got the vaccine were more likely to experience side effects than those on the placebo, so I figured the worse I felt, the more likely I was building Covid immunity. But I felt absolutely fine, which was oddly disappointing. On my last visit, the nurse said she didn’t know when the study would be unblinded, if ever. So I may never find out what was in my shot.

Even if I did get the placebo, I’m making an important contribution to the vaccine effort, and I’m glad I stepped forward. I would’ve been pleased with 50 percent efficacy; Pfizer’s results, though preliminary, had me doing a jig in my kitchen. I hope this means Covid can be vanquished with many of the 200 vaccine options in various stages of development, and that those vaccines will be deployed as soon as it’s safe to give them out.

I’ll make sure my whole family gets theirs. I hope you do too.

This article is part of Reset: The Science of Crisis & Recovery, an ongoing series exploring how the world is navigating the coronavirus pandemic, its consequences and the way forward. Reset is supported by a grant from the Alfred P. Sloan Foundation.