Education Corner
Why Is "Serotype 3" Pneumococcus Important?
In Hong Kong, Serotype 3 is a major pathogen threatening public health:
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Main Cause of Invasive Disease: Between 2016 and 2020, Serotype 3 caused 39%–49% of invasive pneumococcal disease (IPD) cases in adults and up to 59%–68% of cases in children locally.
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High-Risk Factor for Children: Nearly 70% of invasive diseases in infants and young children in Hong Kong are caused by Serotype 3.
Comparison of New Conjugate Vaccines (15-valent / 20-valent / 21-valent)
| Comparison Item | 15-valent Conjugate Vaccine (PCV15) | 20-valent Conjugate Vaccine (PCV20) | 21-valent Conjugate Vaccine (PCV21) |
| Manufacturer | Merck | Pfizer | Merck |
| Suitable Age | 6 weeks or older | 6 weeks or older | 18 years or older |
| Dosage & Doses | • 6 weeks to 7 months: 4 doses • 7 to 11 months: 3 doses • 1 to 2 years: 2 doses • 2 years or older: 1 dose | • 6 weeks to 7 months: 4 doses • 7 to 11 months: 3 doses • 1 to 2 years: 2 doses • 2 years or older: 1 dose | 1 dose only |
| HK Registration Year | 2022 | April 2023 (Launched in 2021) | 2026 |
| Serotypes Covered | 15 types | 20 types | 22 types |
| Core Advantages | • Immunogenicity against Serotype 3 is 60–77% higher than 13-valent and 20-valent vaccines • Adopted by the government since August 2024 to replace the 13-valent vaccine at Maternal and Child Health Centres (MCHCs) | • Covers up to 83% of invasive serotypes, offering broader protection • Recommended by multiple countries including the US, Canada, Japan, and South Korea | • Precisely targets the top three common serotypes in Hong Kong seniors (3, 15A, 23A) • Covers over 70% of invasive serotypes, aligning with the latest WHO recommendations |
Vaccine Types & Scope of Protection
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Conjugate Vaccines (PCV13 / PCV15 / PCV20): Stimulate long-term immune memory. Effectively cover the highly invasive Serotype 3, as well as the highly antibiotic-resistant Serotypes 6A and 19A.
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Polysaccharide Vaccine (PPV23): Covers 23 serotypes, but does not include Serotype 6A, and its immune memory is weaker than that of conjugate vaccines.
Infant & Toddler Vaccination Schedule (15-valent / 20-valent)
| Starting Age | Recommended Total Doses | Vaccination Schedule |
| 6 weeks and older | 4 doses* | Administered at 2 months, 4 months, 6 months, and 12–15 months of age |
| 7 months and older | 3 doses | Completed within approximately 6 months |
| 1 – 2 years old | 2 doses | Administered at least 2 months apart |
| Over 2 years old | 1 dose | 1 dose only |
*Since July 2019, the Department of Health in Hong Kong changed the free pneumococcal vaccination schedule for children born in or after 2019 from 4 doses to 3 doses (removing the 3rd dose at 6 months of age). Parents may choose to have their baby receive a self-paid booster dose at 6 months of age as needed.
Additional Protection: Children over 2 years old who have completed the 15-valent vaccination may consider receiving 1 dose of the 20-valent vaccine to broaden their protection.
Adult & Elderly Vaccination Arrangements
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13-valent / 15-valent Conjugate Vaccine (2 years or older): Only 1 dose is required.
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20-valent Conjugate Vaccine (18 years or older): Only 1 dose is required.
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23-valent Polysaccharide Vaccine: After receiving 1 dose, a 2nd dose may be required after 5 years subject to a doctor's assessment.
Interested in the pneumococcal vaccine? Click the link below to purchase it directly from our online store, or contact us for more information. Pneumococcal Vaccine – Human Health Eshop