Comparative Effectiveness and Antibody Responses to Moderna and Pfizer-BioNTech COVID-19 Vaccines among Hospitalized Veterans - Five Veterans Affairs Medical Centers, United States, February 1-September 30, 2021

• Published in: MMWR. Morbidity and mortality weekly report Vol. 70; no. 49; pp. 1700 - 1705
• Main Authors: Bajema, Kristina L, Dahl, Rebecca M, Evener, Steve L, Prill, Mila M, Rodriguez-Barradas, Maria C, Marconi, Vincent C, Beenhouwer, David O, Holodniy, Mark, Lucero-Obusan, Cynthia, Brown, Sheldon T, Tremarelli, Maraia, Epperson, Monica, Mills, Lisa, Park, So Hee, Rivera-Dominguez, Gilberto, Morones, Rosalba Gomez, Ahmadi-Izadi, Ghazal, Deovic, Rijalda, Mendoza, Chad, Jeong, Chan, Schrag, Stephanie J, Meites, Elissa, Hall, Aron J, Kobayashi, Miwako, McMorrow, Meredith, Verani, Jennifer R, Thornburg, Natalie J, Surie, Diya
• Format: Journal Article Newsletter
• Language: English
• Published: United States U.S. Government Printing Office 10.12.2021; U.S. Center for Disease Control; Centers for Disease Control and Prevention
• Subjects: 2019-nCoV Vaccine mRNA-1273 - administration & dosage; 2019-nCoV Vaccine mRNA-1273 - immunology; Age groups; Aged; Antibodies; Antibodies, Viral - analysis; BNT162 Vaccine - administration & dosage; BNT162 Vaccine - immunology; Cohort Studies; Coronaviruses; COVID-19; COVID-19 - epidemiology; COVID-19 - immunology; COVID-19 - prevention & control; COVID-19 vaccines; Effectiveness; Female; Full Report; Health care facilities; Hospitalization; Hospitalization - statistics & numerical data; Hospitals, Veterans; Humans; Immunization Schedule; Male; Medical centers; Middle Aged; mRNA; Patient Acuity; Pharmaceutical industry; Proteins; Public health; RNA; SARS-CoV-2 - immunology; Severe acute respiratory syndrome coronavirus 2; Time Factors; United States - epidemiology; Vaccine efficacy; Vaccine Efficacy - statistics & numerical data; Vaccines; Veterans; Veterans - statistics & numerical data; Veterans Health Services; United States; Texas; California; United States > US
• ISSN: 0149-2195; 1545-861X
• DOI: 10.15585/MMWR.MM7049A2

The mRNA COVID-19 vaccines (Moderna and Pfizer-BioNTech) provide strong protection against severe COVID-19, including hospitalization, for at least several months after receipt of the second dose (1,2). However, studies examining immune responses and differences in protection against COVID-19-associated hospitalization in real-world settings, including by vaccine product, are limited. To understand how vaccine effectiveness (VE) might change with time, CDC and collaborators assessed the comparative effectiveness of Moderna and Pfizer-BioNTech vaccines in preventing COVID-19-associated hospitalization at two periods (14-119 days and ≥120 days) after receipt of the second vaccine dose among 1,896 U.S. veterans at five Veterans Affairs medical centers (VAMCs) during February 1-September 30, 2021. Among 234 U.S. veterans fully vaccinated with an mRNA COVID-19 vaccine and without evidence of current or prior SARS-CoV-2 infection, serum antibody levels (anti-spike immunoglobulin G [IgG] and anti-receptor binding domain [RBD] IgG) to SARS-CoV-2 were also compared. Adjusted VE 14-119 days following second Moderna vaccine dose was 89.6% (95% CI = 80.1%-94.5%) and after the second Pfizer-BioNTech dose was 86.0% (95% CI = 77.6%-91.3%); at ≥120 days VE was 86.1% (95% CI = 77.7%-91.3%) for Moderna and 75.1% (95% CI = 64.6%-82.4%) for Pfizer-BioNTech. Antibody levels were significantly higher among Moderna recipients than Pfizer-BioNTech recipients across all age groups and periods since vaccination; however, antibody levels among recipients of both products declined between 14-119 days and ≥120 days. These findings from a cohort of older, hospitalized veterans with high prevalences of underlying conditions suggest the importance of booster doses to help maintain long-term protection against severe COVID-19. .