Subacute thyroiditis (SAT) is a thyroid disease associated with viral infections. Its relationship with major histocompatibility complex (MHC) antigens was shown before. SAT cases triggered by different types of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) vaccines have been reported. In this study, human leukocyte antigen (HLA) genotypes of 27 SAT patients (13 vaccine-associated (V-SAT) and 14 non-SARS-CoV-2-infection non-vaccine-associated (non-V-SAT)) were compared with those of 362 healthy donors. HLA analyses were performed with low-resolution DNA-based sequence-specific oligonucleotide or sequence-specific primer methods. Statistical analyses were performed using IBM SPSS Statistics 25 and Stata/MP 14.1 with the hapipf function. Allele and haplotype frequencies were estimated by PyPop and gene[RATE] tool programs. The allele frequencies of HLA-A*11, HLA-B*35, and HLA-C*04 were higher in the patient groups. Both the allele frequency of HLA-A*11 and the haplotype frequency of A*11-B*35-C*04 were higher in the V-SAT group. The A*11-B*35-C*04 haplotype, including all three loci of MHC class I genes, is shown to be associated with the disease for the first time, especially in the V-SAT group. This finding will contribute to a better understanding of the etiopathogenesis of vaccine-associated SAT and the role of HLA genotypes in the functioning mechanisms of the SARS-CoV-2 vaccines.

Introduction: While there is a significant amount of information about invasive meningococcal disease (IMD), meningococcal carriage, and meningococcal vaccines in children and adolescents, data in older adults are limited. Studies of meningococcal carriage and transmission modeling can be utilized to predict the spread of IMD and guide prevention and treatment strategies. Our study’s main objective was to assess the prevalece of Neisseria meningitidis (Nm) carriage, serogroup distribution, and associated risk factors among older adults in Türkiye. Methods: Nasopharyngeal samples were collected between December 2022 and January 2023 from a total of 329 older adults (65 years of age and above). The samples were tested via PCR for Nm, and a serogroup (A, B, C, Y, W, X, E, Z, H) analysis of the positive samples was performed. Results: In total, 329 adults over 65 years of age (150 females and 179 males; 69% were 65–75 years old and 31% were 75 years of age and older) were included in the study. Nm carriage was detected in 46 participants (13.9%), and the serogroup distribution was as follows: 2.4% MenY (n = 8), 1.8% MenB (n = 6), 0.2% MenW (n = 2), and 9.4% non-groupable (n = 31). Other serogroups were not detected. Between the meningococcal carriers and the non-carriers, there were no differences between previous vaccination histories (meningococcal, pneumococcal, influenza, and COVID-19), travel history for Hajj and/or Umrah, and the presence of chronic disease. Of the 16 cases positive for the serogroups Y, B, and W, 13 patients were between the ages of 65 and 74 and three patients were over 75 years old, and these three cases represented MenY. Conclusion: In our study, the percentage of meningococcal carriage was found to be 13.9%, the carriage rate for encapsulated strains was 4.8%, and the most common serogroup was MenY. Men Y was also the only serogroup detected in patients over 75 years of age. The MenY serogroup, which is one of the most important causes of IMD (especially in pneumonia cases) in people older than 65 years, was the most frequently carried serogroup in people over 65 years of age in our study. Adequate surveillance and/or a proper carriage study would help to define potential vaccination strategies for older adults.