Germs in China: Immunity Training Ground?

I got through this winter without getting sick (not more than a few sniffles, anyway), UNTIL two weeks ago, when spring arrived and I got hit by a horrible cough, condemning me to long coughing fits every morning and evening for over two weeks. It was the kind of cough that I thought was “getting better” every day, until evening hit. It was bad, but not bad enough that made me go see a doctor. And it’s now finally almost faded away, about 15 days since it started. (You’ll notice I haven’t been blogging for this same time period.)

But this got me thinking about my own immune system in relation to China. After 16.6 years in China, has my immune system been “trained” at all? I don’t think there’s any way to definitively answer this question, but I’ve got a few thoughts, and I’m hoping others might share their experiences.

fake germs

Growing up in Florida, I was a pretty healthy kid, especially once I got into my teens. My mom was fond of saying, “you rarely get sick, but when you get sick, you get really sick.” I barely remember getting sick at all in college, including the year I studied in Japan. After that I came to China.

My first year in Hangzhou, I had the obligatory newbie food poisoning incident and it was really bad, which ended with me getting an IV in a hospital (as so many illnesses in China tend to). And then as time went on, I would get colds more frequently in China than I had before. I still get hit by the “China germs sucker punch.”

I would expect, after moving to a new environment with a fairly dense population, swimming with a whole new world of germs, to get sick a bit more often than before. And I think this is what has happened, leading up to gradual new “China immunity” layer in my body’s defenses. And over a decade later, I feel that I do get fewer colds, provided that I don’t get too behind on my sleep. But I don’t feel at all confident anymore saying things like “I rarely get sick” now that I live in China.

All this leads me to a few questions I’ve been thinking about:

  1. Do most expats from the USA (or other relatively sparsely populated western countries) get sick more frequently after moving to China?
  2. Are most long-term expats able to build up a stronger immunity to Chinese germs?
  3. Does a long stay in China lead to a permanently stronger immune system in other countries?
  4. Do Chinese immigrants to the USA get sick less often in the USA than they used to in China?

It would be hard to answer these questions through research, and I realize there are quite a few variables involved (I’m no longer in my twenties, for example) but I’m interested in hearing my readers’ anecdotal evidence. So how about it: in your experience, is China an immunity training ground, or does it simply have its way with you until you’ve had enough?


John Pasden

John is a Shanghai-based linguist and entrepreneur, founder of AllSet Learning.


  1. I’m pretty sure the plural of anecdote is data, so here’s mine: I didn’t get sick much before moving to Shanghai, while in Shanghai, or after moving back to the US. I called in to work sick a lot, but that was usually just the Maoming Lu Flu. My wife claims she was almost never sick in China, and is still very healthy after moving to the US.

  2. I lived in China for three years and definitely got sick more often. Every spring and every fall I got a sinus infection. I’ve now been back in Texas for 5 years, and haven’t had a single sinus infection. My wife is from 舟山, and she never got sick either in China or in Texas. However, she does get really bad allergies here, which I seem to be immune to.

  3. An interesting question. Kinda, and kinda not. I think my immune system was more robust before I came to China. For example, I did not fear the wind. I did not fear getting chilled. And I drink cold stuff all the time. Only the last has stayed. Now I try not to have the wind blow on me too much, and I’ll put on a windbreaker or cover my head in a chilly bus or a/c at the mall. My stomach still responds well to ice and coke and ice water.

    It’s hard to say if this is part of getting older, or a response to China germs. My last trip to California, after about two weeks I did feel a bit better overall. Generally, I can hold off a cold/flu here, and/or self treat for a couple weeks. I refuse to do the IV drip thing. I have seen too many friends get scary hives after an IV drip. I think all of last year I didn’t have a cold, but did come down with a bout over CNY.

    Scientifically speaking, I don’t think the immune system will dramatically change in mid-life due to environment. My understanding is that the basic immune anti-bodies and how they will react are established when quite young. My mom did like to stick me around other sick kids, and it was pretty much just chicken soup, Vicks and rest if I came down with a cold.

    What I do think has happened is that my strong reluctance to go to a local clinic has made me very aware and conscious about staying fit, eating well, getting sleep, etc. Thus, I’d say I’m probably the healthiest I’ve ever been on-average if I was to compare overall time in China to overall times outside of China.


  4. Contributed by email:

    Dear John,

    I am big fan of your work (podcasts, and I just discovered your blog ..) Thanks!

    I just read your blog concerning “Germs in China”.

    I am Danish, but have lived in France almost 20 years. Until recently, ever since I got to France, I have been sick all the time. Like you, in the beginning I thought “new germs” ! (and I still believe this is partially true). But I kept on being much more often sick than when I lived in Denmark. And I should have gotten used the new germs, after 20 years, right ?

    However, only a year ago I think I discovered THE reason for being more sick here in France. In France, buildings (including my own house) are less heated than in Denmark (although it’s warmer outside in France!). I think I have been constantly feeling cold in winter, and this has impacted my immune defense in a negative way.

    Now I have a new heating system at home, and added electrical heaters in my office. The only place impossible to heat is the large lecture hall in which I teach a few hours per week, but I now put on my thick down jacket while teaching ! (my student have gotten used to it)

    I almost don’t dare to say it but I have not been sick, not even once, this whole winter….(I have also been careful to get my 8+ hours of sleep every night, wash hands all the time, and so on… πŸ™‚

    I guess in Shanghai it’s never really cold, but I still just wanted to share this story with you just in case it might inspire your research on this topic πŸ™‚ (as you say yourself, there are quite a few variables involved).

    Best regards and stay healthy,

  5. Contributed by email:

    I’m a 72 year old expat living in Nanning. I had a horrific year where I was coughing up phlegm constantly. An X-ray showed a lot of bacteria. I thought that I had bronchitis but no symptoms all winter. The main difference this year is a de-humidifier and more heat on cold days. I dress more carefully when I’m on my e-bike. My friends from various countries drink beer and eat junk food and are seldom sick. I close windows most of the time now. I deal with young people all of the time and shake hands at the English corner. I think time and building immunity to the local ailments is the answer.


  6. Comment from Facebook:

    I got sick a lot when I first went to China, and then again when I started having serious subway commutes. I think just that many people in metal tubes make germ spreading really easy. Then when I came back to the US I got sick a bunch, and still feel like I get sick more than I did before I went to China, but then again I was also 15 years younger than I am now so that might make a difference.

    -John B

  7. Comment from Facebook:

    I think I get sick because of the air. Office is on the 47th floor and so I feel bang right in the middle of the smog cloud. Have been getting random headaches in office when pollution is bad – am connecting dots.


  8. Stephen Heath Says: May 22, 2017 at 11:10 am

    I moved from UK to Nanning, China, two and a half years ago, and feel that I am significantly more healthy here. However, I think that we should consider the immunity of bacteria (to antibiotics), as well as the immunity of people to bacteria. Antibiotic dispensing in Nanning seems to be unsatisfactory as prescription only medications are mostly available without prescription, wrong advice has been given to me by pharmacies as to how often and for how long an antibiotic should be taken, pack sizes contain too few tablets for the recommended course, tablet sizes do not match the recommended dosage and no advice has been given to me about the importance of completing the course. I feel that these factors are likely to promote antibiotic resistance amongst bacteria.

  9. I lived in China for 18 years, been back in the US now about 4 years. First several years got all the regular foreigner illnesses, bad colds, food poisoning blah blah blah. I never did anything about the bad colds and stomach flu until about 10 years in then I got hit one year with a horrible stomach flu deep in the winter. Laying on the bathroom floor with stuff coming out of both ends and not being able to get up. The worst illness I ever had in my life and all alone (during Chinese new year) After that I got a yearly flu shot. After that I would still get a yearly cold that would last until spring but I never got sick like I did that one time. After coming home I have had a few colds but nothing like my Chinese colds. In fact I have a cold now and it seems to be the worst cold I have had since coming back home but it is still not too bad comparatively.

  10. I’ve Partially grown up in China, previously in the states and then from 14-22 in China. When I was first in Beijing I got sick every other week, then moved to the south where the air was better and now I get sick every other month maybe. But I’ve seen both sides where people are sick all the time and some people never. Typically I’m a very healthy person. I get enough sleep, water, I eat very healthy and exercise 4-6 times a week, but still I am the person who gets sick the most. I really do wish there were studies on this.

Leave a Reply