Mountains, Altitude, and Vaccines: A Practical Highland Survival Kit

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每次去那边，总是这样冒冒然地跑过去，偶有顺利，也有高反至痛苦万分的境地。正如我先前对女儿说的：美好的风景总藏在少人问津之处。事实亦然。上个月去的岳阳楼、剑门关，皆是如此。雄厚的历史背景之下，故址也一迁再迁；至于剑门关，这个当年蜀国兵家必争之地，如今看来终究是盆地边缘的悬崖绝壁，不算太高，对常去爬山的人也谈不上多险，只能说自有其“气质”。

不过，大山与我，总是互相惦记。去过多次贡嘎、梅里、南迦巴瓦，多次都藏在云层中无缘相见。也正因那份无缘，反倒教人念念不忘，一次又一次来到山前。

记得冈仁波齐倒是愿召见我这样的游客。虽说有那么两次马年转山，高反便在路上袭来，但无数回在梦里仍会忆起那垭口的经幡、深夜璀璨的银河，以及白日里直上云霄的天阶。当然，更让人揣在心窝里的，还是那按捺不住的高反。

说到高反，我倒想起“教主”曾给家人准备过一份抗高反药单，于是又翻出那篇《如何预防高反》，细细研究。

• 用乙酰唑胺预防高原反应：125 mg，每12小时一次，自出发前1天开始。
• 通常在持续上升阶段服用；到达计划的最高过夜海拔后再维持48小时，若无症状即可停药。
• 若为慢上升：>2,500–3,000 m 后，每天睡眠海拔上升不超过300–500 m，每3–4天加一个休息日。

注意事项：

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• 不建议连续服用数周至数月。
• 不推荐银杏、红景天等作为可靠预防。
• 最有效的非药物仍是控制上升速率。

难怪许多人慢慢开车过去反倒不易高反。若某一天改坐飞机呢？在那种快速上升难以避免时，可在医生指导下使用硝苯地平或 PDE5 抑制剂作为药物预防。大模型告诉我，其效果与机制（降低肺动脉压、改善血流分配）已在《新英格兰医学杂志》和 WMS（Wilderness Medical Society，荒野医学会）指南中得到充分论证。

既然关心高反，也索性整理一份去川西的疫苗清单。针对中国西部（川西/西藏/新疆），尤其行走荒野较多者，宜做好准备。

• 流感：当季接种（北半球约 10–次年 3 月）。
• 破伤风-白喉-百日咳（Tdap）：成年期至少 1 次 Tdap，此后每 10 年 Td/Tdap 加强 1 次；若 >10 年未加强，请补 1 针。
• 麻疹-腮腺炎-风疹（MMR）：共 2 针；不清楚接种史就补齐。
• 水痘：未得过或未全程接种者补 2 针。
• 小儿麻痹（脊灰，IPV）：童年全程者一般不需加强；可与医生讨论打一针终身加强（中国/欧洲不要求，印度仅在特定情形考虑）。
• 甲肝（HepA）：0 与 6 个月各 1 针；出发前打第 1 针已能提供主要保护。乙肝（HepB）：常规 3 针 0-1-6 月，或 Heplisav-B 两针 0 与 1 月。
• 亦可选 A+B 联合 Twinrix 加速程：0、7、21 天＋12 个月加强。伤寒：肌注多糖疫苗（出发前 ≥2 周），或口服活菌 4 粒（出发前 ≥1 周；免疫缺陷/正在服用抗生素者不选口服）。
• 视暴露情况考虑：狂犬病预暴露（2 剂法：第 0、7 天；适用于长期户外、接触犬畜/野生动物、医疗资源匮乏地区。预暴露后若被咬，仅需 2 剂暴露后疫苗，且可免用人免疫球蛋白）。

选择性疫苗

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日本脑炎（JE，IXIARO 2 针：0 与 28 天；18–65 岁可加速为 0 与 7 天）。更适合在四川盆地/川南低海拔、夏秋、农村/稻田/猪舍附近长期停留者；西藏高海拔蚊媒少，常无此必要。

写到这儿，也算是去川西的“标准姿势”了。像我这种有两次以上高原反应史的，更该加倍小心。若不吃药，再次发生高原反应的可能性很大：一来，既往发病史是最强、最稳定的独立危险因素之一；再者，就高原肺水肿而言，复发倾向尤为明显，发病风险约为无既往史者的 2–5 倍。

山就在那儿，静静等着与你再次相见。

暮春良朝起，秋服向东郊。 山净余霭尽，天清微霄高。 南风来拂物，新苗得轻包。 独行欣且感，怀抱自逍遥。

Mountains, Altitude, and Vaccines: A Practical Highland Survival Kit

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Every time I head out that way, I tend to dash off on impulse—sometimes everything goes smoothly, and sometimes the altitude hits so hard it feels almost unendurable. As I once told my daughter: the loveliest landscapes hide where few people go. It keeps proving true. Just last month at Yueyang Tower and Jianmen Pass, it was the same. Beneath their weight of history, the “original” sites have shifted and been rebuilt more than once. And Jianmen Pass—once a must-hold chokepoint for the Shu state—turns out, to modern eyes, to be a sheer wall on the rim of a basin. Not very high, not especially perilous to anyone who hikes often; it simply has a temperament of its own.

The mountains and I, though, never quite forget each other. I’ve gone to Gongga, Meili, and Namcha Barwa more than once, and more than once they stayed sealed in the clouds, refusing me a glimpse. It’s that very refusal—no meeting granted—that haunts me into returning, again and again, to stand before them.

Kailash, at least, once seemed willing to grant me an audience. Twice in a Year of the Horse kora, altitude sickness swept in along the trail, and yet I still dream of the prayer flags thrumming at the pass, the midnight Milky Way blazing, and, in daylight, the stairway that appears to run straight up into the sky. What I tuck closest to the heart, though, is still that unruly altitude illness, impossible to hold down.

Speaking of altitude sickness, I remember the family “Guru” once drew up a medication plan for us. So I dug up that old piece, “How to Prevent Altitude Sickness,” and studied it line by line.

Acetazolamide for prevention: 125 mg every 12 hours, starting one day before departure.

In general, take it through the period of continuous ascent; after reaching your planned highest sleeping altitude, continue for another 48 hours. If you have no symptoms, you can stop.

For slow ascents: once above 2,500–3,000 m, raise sleeping altitude by no more than 300–500 m per day, and insert a rest day every 3–4 days.

Notes:

• Do not take acetazolamide continuously for weeks to months.
• Ginkgo biloba and Rhodiola are not reliable for prevention.
• The most effective non-drug strategy is still to control the ascent rate.

No wonder those who drive up slowly often avoid getting sick. But what if one day I fly? When rapid ascent can’t be avoided, nifedipine or a PDE5 inhibitor can be used preventively under a doctor’s guidance. The large model assures me their effects and mechanisms—lowering pulmonary arterial pressure and improving blood-flow distribution—are well supported in the New England Journal of Medicine and in the Wilderness Medical Society (WMS) guidelines.

Since I’m thinking about altitude, I might as well set down a vaccine checklist for Western Sichuan. For western China (Sichuan/Tibet/Xinjiang), especially if you’ll be out in the backcountry, it’s worth being prepared.

• Influenza: Get the seasonal shot (Northern Hemisphere roughly October to March).
• Tetanus–diphtheria–pertussis (Tdap): At least one Tdap in adulthood, then a Td/Tdap booster every 10 years; if it’s been over 10 years, get a booster.
• Measles–mumps–rubella (MMR): Two doses; if your history is unclear, complete the series.
• Varicella: If you’ve never had chickenpox or haven’t completed the series, get two doses.
• Polio (IPV): If you completed the childhood series, no booster is generally needed; you can discuss a one-time lifetime booster with your doctor (not required in China/Europe; considered in India only in specific situations).
• Hepatitis A (HepA): Two doses at 0 and 6 months; the first dose before departure provides primary protection.
• Hepatitis B (HepB): Standard three-dose series at 0–1–6 months, or Heplisav-B in two doses at 0 and 1 month.
• Combined A+B (Twinrix) accelerated schedule: days 0, 7, 21, plus a booster at 12 months.
• Typhoid: Injectable polysaccharide vaccine (at least 2 weeks before departure), or oral live vaccine (4 capsules, at least 1 week before departure; not for the immunocompromised or those on antibiotics).

Depending on exposure:

• Rabies pre-exposure (2-dose schedule: days 0 and 7), suitable for long days outdoors, contact with dogs/livestock/wild animals, or travel in areas with limited medical care. If bitten after pre-exposure vaccination, only two post-exposure doses are needed, and human rabies immunoglobulin can be omitted.

Optional:

• Japanese encephalitis (JE, IXIARO: 2 doses on days 0 and 28; for ages 18–65, can be accelerated to days 0 and 7). Most relevant for long stays in low-altitude rural areas of the Sichuan Basin or southern Sichuan in summer and fall, especially near rice paddies or pig farms; in high-altitude Tibet, mosquito vectors are scarce and JE is often unnecessary.

With all this down, I suppose that’s the “standard posture” for heading into Western Sichuan. Someone like me, with more than two bouts of altitude illness, ought to be doubly careful. Without medication, the odds of it returning are high: past episodes are among the strongest and most consistent independent risk factors; and for high-altitude pulmonary edema in particular, the tendency to relapse is pronounced—the risk is roughly two to five times that of someone with no prior history.

The mountains are there, waiting quietly for our next meeting.

On a fine morning in late spring, dressed for autumn,
I walk east to the outskirts.
The mountains stand rinsed clean, the last veils of mist gone;
the sky is lucent and high.
A southern breeze combs the world;
new shoots are lightly swaddled.
I walk alone, glad and moved, my heart ranging free.