Booster mRNA Vaccination Prevents Breakthrough Severe COVID-19 Infections


Dinç H. Ö., KIRKOYUN UYSAL H., Can G., Budak B., Daşdemir F. O., KESKİN E., ...Daha Fazla

Journal of Medical Virology, cilt.98, sa.6, 2026 (SCI-Expanded, Scopus)

  • Yayın Türü: Makale / Tam Makale
  • Cilt numarası: 98 Sayı: 6
  • Basım Tarihi: 2026
  • Doi Numarası: 10.1002/jmv.71026
  • Dergi Adı: Journal of Medical Virology
  • Derginin Tarandığı İndeksler: Science Citation Index Expanded (SCI-EXPANDED), Scopus, BIOSIS, CAB Abstracts, Chemical Abstracts Core, EMBASE, MEDLINE, Biomedical Reference Collection: Corporate Edition (EBSCO), Health Research Premium Collection (ProQuest)
  • Anahtar Kelimeler: antibody, BNT162b2, COVID-19, ELISA, SARS-CoV-2
  • İstanbul Üniversitesi-Cerrahpaşa Adresli: Evet

Özet

This study aimed to assess the humoral immune response following administration of a BNT162b2 mRNA COVID-19 booster dose and to evaluate its association with the development of SARS-CoV-2 infection after vaccination. Between July 2021 and February 2022, serum samples were collected from 313 individuals 28 days after receiving a COVID-19 booster dose. Quantitative SARS-CoV-2 IgG antibodies directed against the receptor-binding domain (RBD) of the spike protein were measured using a chemiluminescent microparticle immunoassay. Neutralizing antibody activity, defined as inhibition of the RBD–ACE2 interaction, was evaluated semi-quantitatively by a competitive ELISA. Participants were followed for 6 months after the final dose to identify confirmed SARS-CoV-2 infections. The cohort included 97 males (31%) and 216 females (69%), with a mean age of 39.43 years. The median SARS-CoV-2 IgG antibody level at day 28 was 7713.3 AU/mL, and the median neutralizing antibody inhibition rate was 99.2%. Antibody levels were not significantly associated with age or comorbidities. Booster vaccination induced a strong humoral immune response in all participants. However, the occurrence of post-vaccination infections despite high antibody levels suggests immune escape by emerging variants. While vaccines may not fully prevent infection, they provide substantial protection against severe disease and mortality.