Vaccine effectiveness of primary series and booster doses against covid-19 associated hospital admissions in the United States: living test negative design study

• Published in: BMJ (Online) 2022-10, Vol.379, p.e072065-e072065
• Main Authors: Rhoads, Jillian P, Surie, Diya, Gaglani, Manjusha, Ginde, Adit A, Casey, Jonathan D, Files, D Clark, Hager, David N, Mohamed, Amira, Johnson, Nicholas J, Steingrub, Jay S, Brown, Samuel M, Lauring, Adam S, Khan, Akram, Duggal, Abhijit, Mallow, Christopher, Halasa, Natasha, Grijalva, Carlos G, Lindsell, Christopher J, Lester, Sandra N, Thornburg, Natalie J, Park, SoHee, Patel, Manish M, Ghamande, Shekhar, Murthy, Kempapura, McKillop, Amanda, Hoffman, Eric, Zayed, Martha, Kozikowski, Lori-Ann, Ouellette, Scott, Devilla, Arnaldo, Grafals, Ana, Redman, Kimberly, Scaffidi, Douglas, Mehkri, Omar, Brennan, Connery, Ashok, Kiran, Stanley, Nicholas, Zhang, Sophia, Prekker, Matthew, Erickson, Heidi, Tordsen, Walker, Smith, Cassie, Rothman, Richard E, Nair, Rahul, Karow, Sarah, Robart, Emily, Maldonado, Paulo Nunes, Khan, Maryiam, So, Preston, So, Madison, Schwartz, Elizabeth, Hough, Catherine L, Jung, Haeun, Huynh, Bao, Villanueva-Vargas, Cynthia, Villanueva-Vargas, Juliana, Quadri, Suha, Gordon, Alexandra June, Levitt, Joe, Perez, Cynthia, Visweswaran, Anita, Qadir, Nida, Garner, Omai, Douin, David, Huynh, David, Steinwand, Aimee, Mohr, Nicholas, Nassar, Paul, Landers, Shannon, Nielsen, Karin, Rivas, Carolina, Monto, Arnold, Thomas, Lara, Valvano, Weronika Damek, Fong, Rebecca, Fitzsimmons, William J, Blair, Christopher, Baker, Leigh, Crider, Christine D, Steinbock, Kyle A, Anderson, Layla A, Jones, Ian, Womack, Kelsey, Kampe, Christy, Johnson, Jakea, Rice, Todd, Short, Laura L, Ezzell, Lauren J, Whitsett, Margaret E, Hargrave, Samarian J, Blair, Marcia, Peterson, Bryan P M, LaRose, Mary, Landreth, Leigha, Babcock, Hilary, Bongu, Jahnavi, Cass, Candice, Wallace, Meghan, Arter, Olivia G
• Format: Article
• Language: English
• Subjects: Adult; Aged; BNT162 Vaccine; Case-Control Studies; Clinical outcomes; Collaboration; Combined vaccines; Coronaviruses; COVID-19 - epidemiology; COVID-19 - prevention & control; COVID-19 Vaccines; Disease control; Hospitalization; Hospitals; Humans; Immunocompetence; Immunocompromised hosts; Immunosuppression; Infections; Influenza; Medical laboratories; Medical records; Middle Aged; mRNA; mRNA vaccines; Patient admissions; Patients; SARS-CoV-2; Severe acute respiratory syndrome coronavirus 2; United States - epidemiology; Vaccine Efficacy; Vaccines; Ventilators
• ISSN: 1756-1833; 1756-1833
• DOI: 10.1136/bmj-2022-072065

AbstractObjectiveTo compare the effectiveness of a primary covid-19 vaccine series plus booster doses with a primary series alone for the prevention of hospital admission with omicron related covid-19 in the United States.DesignMulticenter observational case-control study with a test negative design.SettingHospitals in 18 US states.Participants4760 adults admitted to one of 21 hospitals with acute respiratory symptoms between 26 December 2021 and 30 June 2022, a period when the omicron variant was dominant. Participants included 2385 (50.1%) patients with laboratory confirmed covid-19 (cases) and 2375 (49.9%) patients who tested negative for SARS-CoV-2 (controls).Main outcome measuresThe main outcome was vaccine effectiveness against hospital admission with covid-19 for a primary series plus booster doses and a primary series alone by comparing the odds of being vaccinated with each of these regimens versus being unvaccinated among cases versus controls. Vaccine effectiveness analyses were stratified by immunosuppression status (immunocompetent, immunocompromised). The primary analysis evaluated all covid-19 vaccine types combined, and secondary analyses evaluated specific vaccine products.ResultsOverall, median age of participants was 64 years (interquartile range 52-75 years), 994 (20.8%) were immunocompromised, 85 (1.8%) were vaccinated with a primary series plus two boosters, 1367 (28.7%) with a primary series plus one booster, and 1875 (39.3%) with a primary series alone, and 1433 (30.1%) were unvaccinated. Among immunocompetent participants, vaccine effectiveness for prevention of hospital admission with omicron related covid-19 for a primary series plus two boosters was 63% (95% confidence interval 37% to 78%), a primary series plus one booster was 65% (58% to 71%), and for a primary series alone was 37% (25% to 47%) (P