Abstract
Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) Delta variant breakthrough infections in nursing home residents following vaccination with Comirnaty® COVID-19 vaccine were characterized. In total, 201 participants (median age, 87 years; range, 64-100; 133 female) from two nursing homes in the Valencian community (Spain) were included. SARS-CoV-2-Spike (S) antibody responses were determined by a lateral flow immunocromatography (LFIC) assay and by quantitative electrochemiluminescent assay in LFIC-negative participants. SARS-CoV-2-S-IFNγ T cells were enumerated by flow cytometry in 10 participants. Nasopharyngeal SARS-CoV-2 RNA loads were quantified by real-time polymerase chain reaction assays. Vaccine breakthrough COVID-19 due to the Delta variant occurred in 39 residents (median age, 87 years; range, 69-96; 31 female) at a median of 6.5 months after vaccination (nine requiring hospitalization). Breakthrough infections occurred at a higher rate (p < 0.0001) in residents who had not been previously infected with SARS-CoV-2 (naïve) (33/108; 18%) than in those with prior diagnosis of SARS-CoV-2 infection (experienced) (6/93; 6.4%), and were more likely (p < 0.0001) to develop in residents who tested negative by LFIC (20/49) at 3 months after vaccination as compared to their LFIC-positive counterparts (19/142). Among LFIC-negative residents, a trend towards lower plasma anti-RBD antibody levels was noticed in those developing breakthrough infection (p = 0.16). SARS-CoV-2 RNA loads in nasopharyngeal specimens were lower in SARS-CoV-2-experienced residents (p < 0.001) and in those testing positive by LFIC (p = 0.13). The frequency of SARS-CoV-2-S-reactive T cells at 3 months was similar in LFIC-negative residents with (n = 7) or without (n = 3) breakthrough infection. Prior history of SARS-CoV-2 infection and detection of S-reactive antibodies by LFIC at 3 months is associated with a lower risk of Delta-variant breakthrough infection in nursing home residents at midterm after Comirnaty® COVID-19 vaccination.
Keywords: Comirnaty® COVID-19 vaccine; SARS-CoV-2 Delta variant; anti-spike antibodies; breakthrough infection; nursing home residents; spike-reactive T cells.
【저자키워드】 Breakthrough infection, SARS-CoV-2 Delta variant, anti-spike antibodies, Comirnaty® COVID-19 vaccine, nursing home residents, spike-reactive T cells., 【초록키워드】 COVID-19, severe acute respiratory syndrome coronavirus 2, SARS-CoV-2, coronavirus, COVID-19 vaccine, vaccination, Hospitalization, antibody, T cells, SARS-COV-2 infection, nursing home, Antibody Response, Infection, Delta, severe acute respiratory syndrome Coronavirus, delta variant, flow cytometry, lateral flow, polymerase chain reaction, T cell, Antibody responses, COVID-19 vaccination, female, Spain, Community, breakthrough infections, plasma, SARS-CoV-2 RNA, Breakthrough infection, respiratory, nursing homes, Quantitative, anti-spike antibodies, Anti-spike, Frequency, anti-RBD, determined by, Chain Reaction, acute respiratory syndrome, Participants, prior diagnosis, acute respiratory syndrome coronavirus, median age, lower risk, naïve, participant, positive, nasopharyngeal specimen, RNA loads, polymerase chain, tested, develop, occurred, assays, nine, median, characterized, quantified, diagnosis of SARS-CoV-2, infected with SARS-CoV-2, Valencian, 【제목키워드】 SARS-CoV-2, COVID-19 vaccination,