Viral dynamics of the SARS-CoV-2 Omicron Variant among household contacts with 2 or 3 COVID-19 vaccine doses. Issue 6 (December 2022)

• Record Type: Journal Article
• Authors: Kandel, Christopher; Lee, Yaejin; Taylor, Maureen; Llanes, Andrea; McCready, Janine; Crowl, Gloria; Powis, Jeff; Li, Angel Xinliu; Shigayeva, Altynay; Yip, Lily; Katz, Kevin; Kozak, Robert; Mubareka, Samira; McGeer, Allison
• Is Part Of: Journal of infection. Volume 85:Issue 6(2022)
• Page Start: 666
• Page End: 670
• Publication Date: 2022-12
• Subjects: COVID-19 -- Omicron -- Viral trajectory; Infection -- Periodicals; Bacterial Infections -- Periodicals; Communicable Diseases -- Periodicals; Electronic journals; 616.905
• DOI: 10.1016/j.jinf.2022.10.027
• Languages: English
• ISSNs: 0163-4453

Abstract

Highlights: Peak viral load and duration of PCR positivity of participants infected with Omicron were unchanged by number of vaccine doses. No difference in viral trajectories between those with two and three COVID-19 vaccine doses. Symptoms began 4 days prior to 3 days after first detection of SARS-CoV-2. Individual trajectories of SARS-CoV-2 PCR positivity are variable. Abstract: Objectives: SARS-CoV-2 shedding has changed as new variants have emerged. It is important to understand the trajectory of PCR positivity due to Omicron in vaccinated populations. Methods: Double- or triple-vaccinated adult household contacts of individuals with COVID-19 self-collected oral-nasal swabs for 14 days. A hierarchical linear model estimated viral load trajectories and an exploratory logistic regression model assessed for factors associated with viral detection before symptom onset. Results: Forty-one participants developed COVID-19 with 37 (90%) symptomatic. Viral load peaked 3 days after symptom onset at a median concentration of 8.83 log10 copies/milliliter (range 5.95–10.32) and the mean difference between participants with two or three COVID-19 vaccine doses was 0.02 log10 copies/milliliter (95% CI -0.13 to 0.16). PCR positivity began with a range of 4 days prior to 3 days after symptom onset and was positive on the day of symptom onset in 76% (28/37). SARS-CoV-2 detection on the day of symptom onset was less likely among those with 2 vaccine doses (OR 0.13, 95%CI 0.02–0.79). 68% (25/37) of infected participants had detectable SARS-CoV-2 with Ct<30 at 7 days after symptom onset. Conclusions: Peak viral load and duration of PCR positivity were similar in participants with COVID-19 after two versus three COVID-19 vaccine doses. Onset of viral detection relative to symptom onset was variable.