Vaccination against SARS-CoV-2 was associated with reduced Covid-19 symptom severity in a sample of low to moderate risk adults who were enrolled in an outpatient Covid-19 treatment trial. Boosting was associated with further reduction in symptoms.
Keywords: COVID-19, SARS-CoV-2, vaccine, symptoms
Abstract
Background
SARS-CoV-2 vaccination has decreasing protection from acquiring any infection with emergence of new variants; however, vaccination continues to protect against progression to severe COVID-19. The impact of vaccination status on symptoms over time is less clear.
Methods
Within a randomized trial on early outpatient COVID-19 therapy testing metformin, ivermectin, and/or fluvoxamine, participants recorded symptoms daily for 14 days. Participants were given a paper symptom diary allowing them to circle the severity of 14 symptoms as none (0), mild (1), moderate (2), or severe (3). This is a secondary analysis of clinical trial data on symptom severity over time using generalized estimating equations comparing those unvaccinated, SARS-CoV-2 vaccinated with primary vaccine series only, or vaccine-boosted.
Results
The parent clinical trial prospectively enrolled 1323 participants, of whom 1062 (80%) prospectively recorded some daily symptom data. Of these, 480 (45%) were unvaccinated, 530 (50%) were vaccinated with primary series only, and 52 (5%) vaccine-boosted. Overall symptom severity was least for the vaccine-boosted group and most severe for unvaccinated at baseline and over the 14 days (P < 0.001). Individual symptoms were least severe in the vaccine-boosted group including: cough, chills, fever, nausea, fatigue, myalgia, headache, and diarrhea, as well as smell and taste abnormalities. Results were consistent over delta and omicron variant time periods.
Conclusions
SARS-CoV-2 vaccine-boosted participants had the least severe symptoms during COVID-19 which abated the quickest over time.
Graphical Abstract
Graphical Abstract.
Contributor Information
David R Boulware, Department of Medicine, Medical School, University of Minnesota, Minneapolis, MN, USA.
Thomas A Murray, Division of Biostatistics, School of Public Health, University of Minnesota, Minneapolis, MN, USA.
Jennifer L Proper, Division of Biostatistics, School of Public Health, University of Minnesota, Minneapolis, MN, USA.
Christopher J Tignanelli, Department of Surgery, Medical School, University of Minnesota, Minneapolis, MN, USA.
John B Buse, Department of Medicine, School of Medicine, University of North Carolina, Chapel Hill, NC, USA.
David M Liebovitz, Department of Medicine, Northwestern University Feinberg School of Medicine, Chicago, IL, USA.
Jacinda M Nicklas, Department of Medicine, School of Medicine, University of Colorado-Anschutz Medical Campus, Aurora, CO, USA.
Kenneth Cohen, UnitedHealth Group, Optum Labs, Minnetonka, MN, USA.
Michael A Puskarich, Department of Emergency Medicine, School of Medicine, University of Minnesota, Minneapolis, MN, USA; Department of Emergency Medicine, Hennepin County Medical Center, Minneapolis, MN, USA.
Hrishikesh K Belani, Department of Medicine, Olive View - University of California, Los Angeles, CA, USA.
Lianne K Siegel, Division of Biostatistics, School of Public Health, University of Minnesota, Minneapolis, MN, USA.
Nichole R Klatt, Department of Surgery, Medical School, University of Minnesota, Minneapolis, MN, USA.
David J Odde, Department of Medicine, Olive View - University of California, Los Angeles, CA, USA.
Amy B Karger, Department of Laboratory Medicine and Pathology, Medical School, University of Minnesota, Minneapolis, MN, USA.
Nicholas E Ingraham, Department of Medicine, Medical School, University of Minnesota, Minneapolis, MN, USA.
Katrina M Hartman, Department of Medicine, Medical School, University of Minnesota, Minneapolis, MN, USA.
Via Rao, Division of Biostatistics, School of Public Health, University of Minnesota, Minneapolis, MN, USA.
Aubrey A Hagen, Department of Medicine, Medical School, University of Minnesota, Minneapolis, MN, USA.
Barkha Patel, Department of Medicine, Medical School, University of Minnesota, Minneapolis, MN, USA.
Sarah L Fenno, Department of Medicine, Medical School, University of Minnesota, Minneapolis, MN, USA.
Nandini Avula, Department of Medicine, Medical School, University of Minnesota, Minneapolis, MN, USA.
Neha V Reddy, Department of Medicine, Medical School, University of Minnesota, Minneapolis, MN, USA.
Spencer M Erickson, Department of Medicine, Medical School, University of Minnesota, Minneapolis, MN, USA.
Sarah Lindberg, Division of Biostatistics, School of Public Health, University of Minnesota, Minneapolis, MN, USA.
Regina Fricton, Department of Medicine, Northwestern University Feinberg School of Medicine, Chicago, IL, USA.
Samuel Lee, Department of Medicine, Northwestern University Feinberg School of Medicine, Chicago, IL, USA.
Adnin Zaman, Department of Medicine, School of Medicine, University of Colorado-Anschutz Medical Campus, Aurora, CO, USA.
Hanna G Saveraid, Department of Medicine, Medical School, University of Minnesota, Minneapolis, MN, USA.
Walker J Tordsen, Department of Emergency Medicine, Hennepin County Medical Center, Minneapolis, MN, USA.
Matthew F Pullen, Department of Medicine, Medical School, University of Minnesota, Minneapolis, MN, USA.
Nancy E Sherwood, Division of Epidemiology and Community Health, School of Public Health, University of Minnesota, Minneapolis, MN, USA.
Jared D Huling, Division of Biostatistics, School of Public Health, University of Minnesota, Minneapolis, MN, USA.
Carolyn T Bramante, Department of Medicine, Medical School, University of Minnesota, Minneapolis, MN, USA.
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