Abstract
Objective: To describe COVID-19 breakthrough infections in two nursing homes (NHs) sites of active COVID-19 clusters despite optimal vaccination coverage.
Methods: A cross-sectional study was conducted in two NHs of south-western France, following the investigation of COVID-19 clusters (February-March 2021). SARS-CoV-2-confirmed infection was defined by positive RT-PCR. Antibodies neutralization capacities were tested in a subgroup of fully-vaccinated and seropositive-residents.
Results: Of the 152 residents, 66% were female with median age 87 years (IQR: 80.0-90.2). Overall, 132 (87%) residents received 2 doses of vaccine, 14 (9%) one dose and 6 (4%) were unvaccinated. Forty-seven (31%) residents had confirmed infection (45 (98%) with variant 20I/501Y.V1). All 6 non-vaccinated residents, 4 /14 who had one dose and 37/132 that had two doses, were infected. Of the 39 residents reporting symptoms, 12 and 3 presented severe and critical disease, respectively. One resident with a confirmed infection died. Infected-residents had a median anti-S IgG titre of 19 116.0 (IQR: 3 028.0-39 681.8 AU/mL), 19 times higher than that of non-infected vaccinated persons (1,207.0; IQR: 494.0-2,782.0). In the subgroup of 19 residents tested for neutralizing antibodies, the neutralizing titre (50%) was strongly positively correlated with the anti-S IgG titre (correlation coefficient = 0.83), and 1.5 times higher for the infected than non-infected residents [5.9 (IQR: 5.3-6.9) vs. 3.6 (2.9-3.8)].
Conclusion: Institutionalized elderly persons who undergo breakthrough infection develop higher titres of anti-S IgGs, which are strongly correlated with the neutralizing capacity of the antibodies. These results advocate for additional vaccine doses in this population.
Keywords: COVID-19; Neutralizing antibodies; SARS-CoV-2, Nursing homes; Vaccine.
【저자키워드】 COVID-19, Vaccine, Neutralizing antibodies, SARS-CoV-2, Nursing homes, 【초록키워드】 SARS-CoV-2, Vaccine, vaccination, Neutralizing antibodies, cross-sectional, variant, Infection, vaccine dose, Coverage, cross-sectional study, female, Cluster, Nursing, France, breakthrough infections, Neutralizing, neutralizing capacity, Breakthrough infection, nursing homes, anti-S IgG, Critical disease, positive RT-PCR, dose, neutralization capacity, median age, titre, doses, IgGs, anti-S, correlation coefficient, reporting symptoms, non-infected, defined, tested, were infected, develop, died, conducted, median, undergo, correlated, positively correlated, the antibodies, 【제목키워드】 Infection, France, Bordeaux,