China’s COVID-19 vaccine development process has been relatively opaque.

Unlike their Western counterparts, Chinese vaccine makers Sinopharm and Sinovac have not published Phase III trial data in peer-reviewed medical journals or released much information about their vaccines beyond press releases and headline efficacy figures, even as Beijing touts the vaccines as a source of national pride and uses them as a means of diplomacy. Sinopharm says its vaccine is 79% effective in preventing COVID-19 infections. Sinovac has not released its own efficacy data, but partners in Turkey, Indonesia, and Brazil have reported efficacy rates ranging from 50% to 91%.

But Chinese vaccine makers still have been successful in marketing their drugs. Sinovac and Sinopharm have gained approval in over a dozen countries and have begun distributing hundreds of millions of COVID-19 doses around the world.

Early Phase I and II data suggest the Chinese vaccines are safe, but without peer-reviewed analysis from later-stage testing, millions of people who’ve been offered the vaccines must rely on scant information as they wrestle with questions about the vaccine’s efficacy, its potential side effects, and how the jabs work across different age groups.

Will Henry, a 31-year-old American teacher in Shanghai, got an email through his school in late December asking if he wanted to get Sinopharm’s vaccine. Henry, who spoke with Fortune for a story about Chinese vaccine makers’ data, said he was hesitant at first, given the lack of transparency in Chinese vaccines. But ultimately he chose to take it to improve the chances that he could safely travel home to the U.S. and see his family. Below, in a conversation edited for length and clarity, Henry tells Fortune about his decision.

Fortune: You got your first jab of the Sinopharm vaccine in Shanghai in early January and your second later that month. Can you describe the experience of receiving the first dose?

Henry: I was looking forward to it, and it seemed like one of the most important vaccines I will get in my life. We took a bus to a repurposed sports complex that had been changed to a vaccine center. When I went, it was really packed. I could tell there were more people there than the organizers had planned for.

I waited in line for about an hour and a half. They then checked my QR code on my phone. Within 10 minutes I had a needle in my arm. (Editor’s note: In the pandemic, China has employed QR codes on health code apps to track individuals’ COVID risk.)

Later I got an email from my health clinic mentioning a paper receipt we were given. If I didn’t have it, [the email said] the school nurse could just check my QR code and print it off for me. 

How did you feel after getting the vaccine?

I had no side effects. I was almost looking forward to having one because I heard that’s a sign that it’s working, but I’m going to take having no side effects as a good thing.

My life hasn’t really changed at all either, but I’m feeling more optimistic. I don’t know if that’s because I got vaccinated or that I’m looking at numbers in the U.S. and seeing more and more people getting vaccinated.  

How did you weigh the pros and cons of getting the Sinopharm vaccine?

It was a pretty easy decision for me, because I’m stuck here right now. I could leave and go back to the U.S. but I’d be risking my social life and job here. But I want to go see my parents, so anything that could make that easier, you know, I would jump at that opportunity. (Editor’s note: For much of 2020, China barred the entry of all foreign nationals, including visa holders. But since last September, China has allowed foreigners to reenter the country after undergoing mandatory two-week hotel quarantines.)

The decision did pit two parts of me against one another. I am very pro-vaccination, but at the same time I was a little bit hesitant about the lack of transparency in China. But I think the fact that a foreign country had approved the Sinopharm vaccine gave me more confidence in it.

Did your colleagues also take it? 

It was a big conversation in the office. What surprised me was that a lot more expat staff percentage-wise were willing to take it than Chinese staff.

I asked [Chinese staff] why, and they’d just tell me it’s not safe yet, or they’re not sure, or it came out too quickly. But I guess for them, they don’t have to leave China, it’s pretty safe here. It’s not a risk they need to take. 

When you go to the U.S., do you think it will matter you got vaccinated in China?

When I go home, I have wondered if [my Chinese vaccine shot] will be accepted in the U.S. Will there be some things I can’t take part in? Or will I need something saying I got vaccinated in the U.S.?

But [based on case numbers], I’d certainly rather be living in China with a vaccine shot that’s 80% effective than in the U.S. with a vaccine shot that’s 90% effective.