[The Vaccination Guide] Understanding the Distinctions between the Four Pneumococcal Vaccines: Which One is Right for You?
Pneumococcus, a prevalent respiratory infection among children, primarily spreads through respiratory droplets or contact with infected surfaces. Regrettably, once contracted, pneumococcus can infiltrate multiple body regions, commonly triggering ailments such as pneumonia, otitis media, sinusitis, and, in severe cases, sepsis and meningitis.
According to data from the Centre for Health Protection between 2009 and 2019, the incidence rate in Hong Kong was approximately 1.7 to 2.9 infections per 100,000 individuals. The highest-risk groups are children aged 5 and below, as well as individuals aged 65 and above. To safeguard the safety of oneself and loved ones, getting vaccinated against pneumococcus is the most effective preventive measure.
Differences Among the Four Pneumococcal Vaccines
Currently, there are two main categories of pneumococcal vaccines approved by the U.S. Food and Drug Administration (FDA), which can be further classified into four types:
1. Pneumococcal Conjugate Vaccines
Pneumococcal Vaccine 13 (Prevenar 13)
Manufacturer: Pfizer
Characteristics: This vaccine contains 13 serotypes of pneumococcus (1, 3, 4, 5, 6A, 6B, 7F, 9V, 14, 18C, 19A, 19F, 23F). After just one dose, 80% of infants are protected against severe pneumococcal infections.
15-valent Pneumococcal Vaccine (Vaxneuvance)
Manufacturer: Merck
Characteristics: This vaccine goes beyond the 13-valent version by including two additional serotypes (22F and 33F), effectively targeting the most common serotype 3 pneumococcus in Hong Kong.
20-valent Pneumococcal Vaccine (Prevenar 20)
Manufacturer: Pfizer
Characteristics: Building upon the 15-valent vaccine, this version adds five more serotypes (8, 10A, 11A, 12F, 15B), providing broader protection.
2. Pneumococcal Polysaccharide Vaccine
23-valent Pneumococcal Vaccine (Pneumovax 23 )
Manufacturer: Merck
15-valent and 23-valent Pneumococcal Vaccines: Ideal for Children and the Elderly
The most prevalent serotype of pneumococcus in Hong Kong is serotype 3, accounting for nearly 60% of cases in children. It is also the primary pathogen responsible for severe infections and hospitalizations, with a mortality rate as high as 30-47%.
With its cutting-edge technology, the 15-valent pneumococcal vaccine not only covers the common serotypes but also specifically targets serotype 3 pneumococcus. It boasts 60% greater immunogenicity compared to standard vaccines, providing extended protection for over 10 years. This vaccine effectively combats the greatest threat posed by pneumococcus in Hong Kong.
Additionally, research indicates that individuals aged 65 and above have over 10 times higher risk of hospitalization due to invasive pneumococcal infection compared to adults aged 18-49. Therefore, vaccination is crucial in preventing infections and severe illness. The 23-valent pneumococcal vaccine encompasses a broader range of serotypes, offering the most comprehensive protection and serving as a comprehensive defense for the elderly.
Childhood Immunisation Programme
The government offers a free 3-dose vaccination service of the 13-valent pneumococcal vaccine for infants born after 2019. The vaccine can be administered at 2, 4, and 12 months of age. If one wishes to receive the 15-valent pneumococcal vaccine, they will need to visit a private healthcare center.
Elderly Vaccination Subsidy Scheme
^High-risk conditions include:
Previously diagnosed with invasive pneumococcal disease, cerebrospinal fluid leakage, or having a cochlear implant
Long-term cardiovascular diseases (except uncomplicated hypertension), pulmonary diseases, liver diseases, or kidney diseases
Metabolic disorders such as diabetes or obesity (with a body mass index of 30 or above)
Weakened immune system (due to conditions such as asplenia, human immunodeficiency virus infection/AIDS, cancer, or corticosteroid therapy)
Chronic neurological disorders that impair respiratory function, difficulty in managing respiratory secretions, increased risk of aspiration, or lack of self-care abilities.
Side Effects of Pneumococcal Vaccines
Common adverse reactions following administration of 13-valent, 15-valent, and 20-valent conjugate vaccines include mild swelling and pain at the injection site, which typically resolve naturally within two days. Some individuals may experience mild fever, fatigue, headache, chills, or muscle pain. Severe pain at the injection site or difficulty moving the arm is extremely rare.
The 23-valent vaccine has been proven to be safe. Common adverse reactions include mild swelling and pain at the injection site, which typically resolve naturally within a few days. Fever, muscle pain, and other more severe local reactions are uncommon.
In conclusion
The type of pneumococcal vaccine, number of doses, and intervals between doses vary depending on individual risk factors and age. It is essential not to generalize. Individuals considering vaccination should consult with a doctor who will develop the safest and most suitable immunization plan based on their personal circumstances.