Here are a few description options for the WordPress post tag “五合一疫苗” in Traditional Chinese, varying in length and focus:

**Option 1: Concise & Informative**

> 五合一疫苗是一種保護幼兒免受多種嚴重疾病侵害的疫苗，包含白喉、百日咳、破傷風、小兒麻痺和乙型嗜血桿菌感染。了解接種時程、注意事項及相關資訊，守護寶寶健康。

English Translation:
> The five-in-one vaccine is a vaccine that protects infants from multiple serious diseases, including diphtheria, pertussis, tetanus, polio, and Haemophilus influenzae type b infection. Learn about the vaccination schedule, precautions, and related information to protect your baby’s health.

**Option 2: Slightly More Detailed & Action-Oriented**

> 關於五合一疫苗的全面資訊，包含接種時間、接種劑量、常見副作用以及重要性。確保您的孩子獲得最佳保護，及時了解疫苗最新資訊，並與您的醫生諮詢接種建議。

English Translation:
> Comprehensive information about the five-in-one vaccine, including vaccination schedules, dosages, common side effects, and its importance. Ensure your child receives the best protection, stay up-to-date with the latest vaccine information, and consult with your doctor for vaccination recommendations.

**Option 3: Emphasizing Parental Responsibility & Benefits**

> 守護寶寶健康，從五合一疫苗開始。這篇文章提供您關於五合一疫苗的必備知識，包括疫苗保護的疾病、接種效益、以及接種後的護理。 了解如何透過接種疫苗，給予您的孩子最全面的保護，減輕疾病帶來的風險。

English Translation:
> Protect your baby’s health, starting with the five-in-one vaccine. This article provides you with essential knowledge about the five-in-one vaccine, including the diseases the vaccine protects against, the benefits of vaccination, and post-vaccination care. Learn how to provide your child with the most comprehensive protection and reduce the risks of diseases through vaccination.

**Option 4: Shorter & Focused on Keyword Inclusion**

> 五合一疫苗，保護您的寶寶免受白喉、百日咳、破傷風、小兒麻痺和乙型嗜血桿菌感染。接種時程、疫苗資訊、重要性，都在此了解！

English Translation:
> Five-in-one vaccine, protecting your baby from diphtheria, pertussis, tetanus, polio, and Haemophilus influenzae type b infection. Vaccination schedules, vaccine information, & importance, all here!

**Which option to choose?**

* **Consider your overall content strategy:** If you offer a lot of in-depth information, then option 2 or 3 could be suitable. If you lean towards more concise content, option 1 or 4 might be a better fit.
* **Character Limit:** WordPress tag descriptions often have character limits. Choose an option that will fit within the allowed space.
* **Target Audience:** Consider what information is *most* important to communicate to the parents or readers searching for “五合一”. Are they seeking to understand the specific diseases covered, benefits, schedule, etc.?

Ultimately, choose the description that best reflects the content of the posts that will be tagged with “五合一疫苗” and that aligns with your overall website/blog goals. Good luck!