Seattle — At 10:16 Pacific time Wednesday morning, I received an injection in my left shoulder. It contained 250 micrograms of an experimental coronavirus vaccine, the first to be tested in humans. I am one of 45 volunteers taking part in a Phase 1 clinical trial that could help end the pandemic.

I was sent home with a thermometer and a diary and told to log my temperature and any symptoms that may arise. I'll still be following Washington state's "Stay Home, Stay Healthy" guidelines, but I'll also return to the clinic regularly for blood draws and a second injection. The research team will be looking to see both that I remain in good health and whether my body begins producing antibodies. All told, this Phase 1 trial is scheduled to last 14 months.

"It'll take a few months to get the data to where we'll feel confident to go to the Phase 2," Anthony Fauci, director of the National Institutes of Allergies and Infectious Diseases, said at a news conference last week. At the clinic, I was told safety may be established in as little as three months.

I learned this trial needed volunteers from a colleague who posted about it on Slack. He shared a link to a form from Kaiser Permanente. "If you've heard the 'a vaccine could be ready in one year' statements, this is the vaccine that they are referring to," he wrote. He would know — he's a vaccine designer at the University of Washington. I clicked the link and typed in some personal information — age, health history, job title — without much thought. I did not expect to hear back.

Eleven days later, my phone rang. "I'm calling about a vaccine study that you may have expressed interest in," the voice mail from Kaiser said. Two hours later, we had scheduled my screening visit.

I am thrilled to be able to participate: I am extremely fortunate enough to be in good health. Having a team of medical professionals tell me as much in preparation for the trial has made that clearer than ever. Clinical trials need healthy volunteers. If there ever was a time to participate in one, this is it. Why would anyone in a position to help not fill out the form?

Getting screened in person was as pleasant as a trip to a clinic could be. I had read the 20-page consent form the night before, but in an exam room, I was told we would start by reviewing it. A physician in a white lab coat waited silently in the chair next to me as I clicked through a text-heavy PowerPoint. Once I finished, she readied a clipboard.

"Are you allergic to anything — food, medications, anything you know of?" she asked.

"No," I replied.

"Any history of heart problems, including high blood pressure?"

"Nope." Her head rose from the clipboard after each question, and our eyes met at every answer. She spoke clearly and calmly. After more than 20 minutes of questions and answers, she peered into my mouth, massaged my lymph nodes, pressed hard on my belly and knocked on my knees. She tested my hearing, shined a light in my eyes and noted that I have acne. A nurse then took my height and weight and drew five vials of blood. Lab work would reveal whether I truly was healthy enough to be admitted.

The nurse and physician who saw me both said they had come out of retirement to help with this study. "This could be the highlight of your career," a friend had told the nurse. They seemed the right people to call back in, having worked before on experimental vaccines, for swine flu and malaria.

The idea behind this vaccine involves a relatively new strategy. All vaccines attempt to train the immune system to respond to an invader before it has breached the gates. Usually, that means injecting a weakened pathogen or part from one into a healthy person to give their immune system a heads up. But instead of injecting me with protein derived from the virus, researchers jabbed me with genetic material encoding such a protein. If my body absorbs this code and carries out its instructions, some of my cells will begin temporarily producing a single protein from the virus. That should prompt my immune system to begin creating antibodies against the viral molecule. Those antibodies will protect against the real virus, scientists hope.

Moderna, the company that produced this candidate vaccine, has tested this new vaccine technology before for other diseases, including influenza and respiratory syncytial virus. It has not yet resulted in a licensed vaccine, and it may never. When it comes to experimenting with the immune system, nothing is guaranteed.

There are some risks, and no one really knows quite what they are yet — that's why there is a trial. Every drug or vaccine that is vying for regulatory approval must eventually be put into people for the first time. Subjects in other mRNA vaccine studies have reported good health overall, though many experience redness and pain at the site of injection, muscle fatigue and headaches — all of which can be severe.

There are other risks, too. No one knows how the human immune system reacts to seeing just this one viral protein. It could produce antibodies that exacerbate infection, as has happened before with a small number of candidate vaccines meant for other infectious diseases. This risk is low, but part of the reason careful studies are always needed before vaccination ramps up.

Volunteers get paid $100 per visit — plus free parking at the clinic.

Hours after receiving my first injection, I am feeling perfectly normal — no pain or any other symptoms. I am part of the highest-dose cohort, and do not know how any of the other subjects are fairing. I'm scheduled for a second injection in early May. I will be working from home and social distancing until then, and likely for much longer.

In normal times, it is easy to imagine what the world will look like in a month. In the era of COVID-19, however, May feels distant. By then, the United States may finally have a grip on things. Normal life may be resuming in my city and in others that have already endured weeks of self-imposed lockdown. More vaccine candidates will surely have begun their own Phase 1 trials.

But the virus has no obligation to go quietly into the night. It could continue to burn through communities around the world for months, even years. It may go dormant in some areas, then reappear. The devastating 1918 influenza pandemic behaved like that, circling the globe and leaving millions of bodies in its wake.

As chance would have it, I carry a personal connection to that pandemic with me every day.

In October 1918, my father's grandfather was among the nearly 200,000 Americans who died during the second wave of the flu outbreak. He was just 23. His widow was left to raise their children, among them my then-18-month-old grandfather, Charles. Charles — who never knew his birth father because of a viral pandemic — died a month before I was born. My parents chose my middle name to honor him.

I hope this vaccine works. If it does, fewer people will perish. And millions more will have to live through less loss as a result of COVID-19.

Ian Haydon is a public information specialist at the University of Washington in Seattle. He wrote this article for the Washington Post.