1. Neutralizing antibody responses to SARS-CoV-2 variants in vaccinated Ontario long-term care home residents and workers
- Author
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Heidi Wood, Bhavisha Rathod, Kathy Manguiat, Nazrana Haq, Yves Durocher, Mohammad Mozafarihashjin, Shiva Barati, Alyssia Robinson, Mario A. Ostrowski, Gary Chao, Julia Garnham Takaoka, Allison McGeer, Anne-Claude Gingras, Mariam Iskilova, Kento T. Abe, Sharon E. Straus, Jennifer L. Gommerman, Salma Sheikh-Mohamed, Queenie Hu, Reuben Samson, Karen Green, Lois Gilbert, W. Rod Hardy, Aimee Paterson, Adrian Pasculescu, Yuko Arita, Alyson Takaoka, Eric G. Marcusson, Jenny Wang, Keelia Quinn De Launay, Karen Colwill, Angel Li, Christine Fahim, and Mahya Fazel-Zarandi
- Subjects
education.field_of_study ,biology ,business.industry ,Population ,Outbreak ,biology.organism_classification ,Neutralization ,Vaccination ,Immune system ,Immunology ,Lentivirus ,biology.protein ,Medicine ,Antibody ,Neutralizing antibody ,business ,education - Abstract
Prioritizing Ontario’s long-term care home (LTCH) residents for vaccination against severe acute respiratory syndrome coronavirus 2 has drastically reduced their disease burden; however, recent LTCH outbreaks of variants of concern (VOCs) have raised questions regarding their immune responses. In 198 residents, mRNA vaccine dose 1 elicited partial spike and receptor binding domain antibody responses, while the second elicited a response at least equivalent to convalescent individuals in most residents. Residents administered mRNA-1273 (Moderna) mounted stronger total and neutralizing antibody responses than those administered BNT162b2 (Pfizer-BioNTech). Two to four weeks after dose 2, residents (n= 119, median age 88) produced 4.8–6.3-fold fewer neutralizing antibodies than staff (n= 78; median age 47) against wild-type (with D614G) pseudotyped lentivirus, and residents administered BNT162b2 produced 3.89-fold fewer neutralizing antibodies than those who received mRNA-1273. These effects were exacerbated upon serum challenge with pseudotyped VOC spike, with up to 7.94-fold reductions in B.1.351 (Beta) neutralization. Cumulatively, weaker vaccine stimulation, age/comorbidities, and the VOC produced an ∼130-fold reduction in apparent neutralization titers in LTCH residents and 37.9% of BNT162b2-vaccinated residents had undetectable neutralizing antibodies to B.1.351. Continued immune response surveillance and additional vaccine doses may be required in this population with known vulnerabilities.
- Published
- 2021