Type 2 Diabetes Impacts Pneumococcal Vaccine Durability
Adults wiht type 2 diabetes (T2D) who receive the pneumococcal conjugate vaccine 10 (PCV10) develop a protective immune response,but this protection wanes more quickly compared to individuals without diabetes,according to a study published in Vaccine.
Did you know? People with type 2 diabetes are at a considerably higher risk of developing pneumococcal infections, which can lead to serious complications like pneumonia and meningitis.
Increased Risk for Diabetics
Individuals with T2D face a greater risk of comorbid conditions, including pneumococcal infections and invasive pneumococcal diseases such as pneumonia and meningitis. Patients with T2D face a threefold increased risk of infections, longer hospital stays, and higher mortality rates compared to their non-diabetic counterparts. Fortunately, several effective PCV formulations are available for both adults and children. However, research on pneumococcal vaccine responses in T2D patients remains limited.
The Immunogenicity Gap
Previous studies have shown varying results regarding antibody responses to pneumococcal vaccines in T2D patients. Some observed higher antibody titers after pneumococcal polysaccharide vaccination (PPV), while others reported important variability in baseline concentrations and antibody functionality.there is limited evidence regarding the immunogenicity of PCV10, especially in individuals with T2D. To address these gaps, researchers evaluated PCV10 humoral immune responses in a high-T2D-burden, resource-limited setting in Pakistan.
Study Findings: Strong Initial Response, Reduced Durability
The study, involving 180 adults with and without T2D who had no prior pneumococcal vaccination history, measured serotype-specific anti-pneumococcal polysaccharide IgG concentrations against pneumococcal serotypes 1, 19F, 9V, and 18C, common in the Pakistani population.
The results showed a robust initial immune response to PCV10, with significantly increased serum IgG against all tested serotypes. Antibody concentrations remained significantly higher than baseline levels eight months post-vaccination. However, when categorized by HbA1c values, individuals without T2D exhibited significantly higher total IgG concentrations than those with T2D after immunization, indicating a less durable vaccine response in the T2D population.
Pro tip: Regular monitoring of antibody levels in T2D patients post-vaccination can help determine the need for booster shots to maintain adequate protection against pneumococcal infections.
Implications and Limitations
The researchers emphasized the importance of these findings, citing higher mortality rates among diabetic patients due to pneumococcal infections. The study confirms that PCV10 effectively increases serotype-specific IgG concentrations for up to eight months in both adults with and without T2D. However, the reduced protection observed after eight months in T2D patients suggests an altered immune response to vaccination in those with T2D.
The investigators noted limitations, including a small sample size and a single-center study design. The eight-month follow-up period was also relatively short. Despite these limitations, the results underscore the importance of repeated pneumococcal vaccination in immunocompromised individuals, including those with T2D.
Expert Commentary
The results indicate that PCV10 is effective at increasing serotype-specific IgG concentration up to 8 months post-vaccination in adults both with and without T2D. However, there was a meaningful decrease in protection after 8 months in patients with T2D, suggesting an altered immune response to vaccination in those with T2D.
Researchers in Vaccine
Frequently Asked Questions (FAQ)
References
- Ahmad I, Burton R, Arshad R, younis B-B, Mirza S. Humoral immune response to 10-valent pneumococcal conjugate vaccine (PCV10) in individuals with type 2 diabetes mellitus.Vaccine. 2025;55(10):127029
- Seminog OO, Goldacre MJ. Risk of pneumonia and pneumococcal disease in people hospitalized with diabetes mellitus: English record-linkage studies. Diabetic Medicine.2013;30(12):1412-1419. doi:10.1111/dme.12260
- petigara T, Zhang D. Pneumococcal vaccine coverage in adults aged 19-64 years, newly diagnosed with chronic conditions in the U.S. American Journal of Preventive Medicine. 2018;54(5):630-636. doi:10.1016/j.amepre.2018.01.033
- Beam TR, Crigler D, Goldman JK.Antibody response to polyvalent pneumococcal polysaccharide vaccine in diabetics. JAMA. 1980;244(23):2621-2624. doi:10.1001/jama.1980.03310230023016
- Matthews CE, Brown EL, Martinez PJ, et al.Impaired function of antibodies to pneumococcal surface protein A but not to capsular polysaccharide in Mexican American adults with type 2 diabetes mellitus. Clin Vaccine immunol. 2012. doi:10.1128/CVI.00268-12
