Navigating Pneumococcal Health: Insights Into Pneumococcal Conjugate Vaccination - Dr Pradeep Bajad

Pneumococcal disease in vaccinated individuals and in the population. Pneumococcal vaccination is indicated for adults with risk factors for pneumococcal disease or for severe adverse outcomes should disease occur. Pneumococcal vaccination is also a routine part of infant and childhood immunization schedules worldwide.

Pneumococcal disease encompasses a range of illnesses caused by pneumococcal bacteria, notably pneumonia—an infection targeting the lungs and one of the most prevalent forms. Aside from pneumonia, these bacteria are responsible for upper respiratory tract infections, ear and sinus infections, meningitis, and Bacteraemia.

While pneumococcal disease can affect anyone, certain groups are at higher risk, including children under 2, individuals with specific medical conditions or risk factors, and adults aged 65 and older.

Pneumococcal disease may present like a mild illness to severe infections and can lead to long-term complications like brain damage or hearing impairment. Fatalities can occur from pneumococcal-related meningitis, bacteraemia, or pneumonia.

Two types of pneumococcal vaccines are available for clinical use: pneumococcal polysaccharide vaccine (PPSV) and pneumococcal conjugate vaccine (PCV)

The pneumococcal conjugate vaccine guards against bacteria responsible for pneumococcal disease, with four variants available: PCV 10, PCV13, PCV15, and PCV20.

The goal of vaccination in adults is to prevent invasive pneumococcal disease (bacteraemic pneumonia, meningitis) and non-bacteraemic pneumonia. Pneumococcal vaccination is recommended for:

• All adults ≥65 years of age
• All Children < 5 years of age
• Adults aged 19 to 64 years with:
• Predisposing chronic medical conditions (e.g., chronic lung disease, chronic liver disease, diabetes mellitus)
• Increased risk of meningitis (e.g., cochlear implant, cerebrospinal fluid [CSF] leak)
• Immunocompromised conditions (e.g., human immunodeficiency virus [HIV] infection, haematologic malignancies) and other conditions associated with altered immunocompetence (functional or anatomic asplenia, chronic renal disease, and nephrotic syndrome)
• Functional or anatomic asplenia

As a pulmonologist, addressing critical respiratory system concerns is essential. Here are the key benefits of the pneumococcal vaccine for patients with respiratory conditions:

1. Pneumonia Prevention: The vaccine significantly reduces the risk of pneumococcal pneumonia, a severe respiratory infection that can be particularly dangerous for patients with existing lung issues.

2. Exacerbation Reduction: By preventing pneumococcal infections, the vaccine helps minimize exacerbations in patients with chronic respiratory diseases like COPD and asthma, leading to improved symptom management and reduced hospitalizations.

3. Complication Avoidance: Respiratory patients are at higher risk of complications from infections, such as pleural effusion and lung abscesses. The vaccine lowers these risks, promoting better respiratory health.

4. Transmission Control: Vaccinated patients are less likely to transmit pneumococcal bacteria to others, including vulnerable populations like young children and older adults, thus contributing to community health.

Vaccine Selection

The Advisory Committee on Immunization Practices (ACIP) recommends the 20-valent PCV (PCV20) alone or the 15-valent PCV (PCV15) followed by the 23-valent PPSV (PPSV23) for all adults with indications for vaccination.

For most adults, including healthy older adults, those with predisposing medical conditions, and those with a history of IPD, PCV20 is preferred, when available, due to the simplicity and lower cost of a single-dose vaccine. This is the most updated recommendation based on availability of PCV 15 and PCV 20.

PCV 15 and PCV 20 vaccinations are not yet available in India. We administer PCV 13 (Prevnar) followed by PPSV 23 for the adult vaccination group based on our national policy and older ACIP recommendation.

One dose PCV13 followed by 1 dose PPSV23 at least 1 year later than repeat regimen when aged ≥65 years is the recommended dosing for the adult aged 19–64 years with certain medical conditions.

Children <5 years of age, particularly those <2 years of age, are at increased risk for invasive pneumococcal disease (IPD), such as meningitis and bacteremia. Routine immunization with a pneumococcal conjugate vaccine (PCV) is effective in preventing IPD in vaccinated children and providing community ("herd") immunity for people who are not vaccinated.

In India, Prevnar (PCV 13) and Synflorix (PCV 10) vaccines are used for paediatric age group vaccination. Prevnar 13 is a vaccine approved for children 6 weeks through 17 years of age for the prevention of invasive disease caused by 13 strains of Streptococcus pneumoniae.

PCV13 immunizations are recommended to all infants as a series of 4 injections: the first at 2 months of age, then at 4 months, 6 months, and 12–15 months. The 10-valent PCV (PCV10) is being used for paediatric age group, its dosing schedule is 2 doses 4 weeks apart and 1 booster; 12 months to 5 years: 2 doses 8 weeks apart.

How effective is the pneumococcal (pneumonia) vaccine?

In short—very effective! Several large research studies have shown that the vaccines are very effective at reducing the chance of getting bacterial pneumonia from Streptococcus pneumoniae and the complications associated with it. When all children started to get the PCV vaccine, the rate of severe pneumococcal infection in the US dropped by 88%.

Pneumonia vaccine is 60%-80% effective when it is given to those with weak immune systems (immunocompromised), people over 65 and older, and people with chronic illnesses.

Although the vaccine is less effective in those with weakened immune systems, the vaccine can significantly lower the risk of serious pneumococcal disease and its complications in most people.

It's crucial to consult with a healthcare professional to determine if PCV13 vaccination is appropriate for you based on your age, health status, and other individual factors.

In summary, pneumonia vaccination (PCV 13) offers a range of benefits, including the prevention of pneumococcal infections, reduced severity of illness, protection for vulnerable populations, lower healthcare utilization, and overall improvement in public health outcomes. Advocating for PCV13 vaccination in the community is essential for safeguarding public health.