Here are a few options for a WordPress post_tag description for “三合一疫苗” (Sānhéyī yìmiáo), in Traditional Chinese, catering to different needs:

**Option 1: Concise and Informative (Good for general use)**

> 三合一疫苗，涵蓋麻疹、腮腺炎、德國麻疹三種疾病的預防接種，有效保護幼童健康。了解疫苗接種時間、副作用及注意事項。

* **Translation:** Three-in-one vaccine, covering measles, mumps, and rubella vaccines, effectively protecting young children’s health. Learn about vaccination schedules, side effects, and precautions.

**Option 2: Focused on Practical Information**

> 關於三合一疫苗的接種資訊，包括接種時程提醒、常見問題解答、接種後護理，以及接種後可能發生的副作用與處理方式。

* **Translation:** Information about the three-in-one vaccine, including reminders for vaccination schedules, answers to frequently asked questions, post-vaccination care, and the treatment of any possible side effects after vaccination.

**Option 3: Emphasizing Prevention and Health (Good for broader appeal)**

> 預防麻疹、腮腺炎、德國麻疹，保護全家健康！三合一疫苗是孩子健康成長的重要防線。詳細介紹疫苗接種的好處、安全性，以及接種前的準備。

* **Translation:** Prevent measles, mumps, and rubella, and protect your family’s health! The three-in-one vaccine is an important line of defense for your child’s healthy growth. Detailed introduction to the benefits, safety of vaccination, and pre-vaccination preparations.

**Option 4: Focusing on Key Benefits and Target Audience (If the Blog is Parent Focused)**

> 守護孩子的健康，從三合一疫苗開始！了解三合一疫苗的接種流程、保護力、適合的接種對象以及接種後需要注意的事項。為您的孩子提供更全面的健康保障。

* **Translation:** Protecting your child’s health, starting with the three-in-one vaccine! Learn about the vaccination process, protective power, suitable recipients and considerations for vaccinations after the three-in-one vaccine. Provide more comprehensive health guarantees for your child.

**Which Option to Choose?**

* Choose the option that best aligns with your blog’s theme, audience, and the overall focus of your content.
* Consider your target audience. Are you writing for parents, healthcare professionals, or a general audience?
* Keep it concise and informative. The description should provide a clear understanding of the tag’s content.
* Use keywords naturally. This will help with SEO.
* You can also adjust and customize these options to best fit your specific needs! Good luck!