Viral Load Dynamics in SARS-CoV-2 Omicron Breakthrough Infections

To determine viral dynamics in Omicron breakthrough infections, we measured severe acute respiratory syndrome coronavirus 2 RNA in 206 double-vaccinated or boostered individuals. During the first 3 days following the onset of symptoms, viral loads were significantly higher (cycle threshold [Ct], 21.76) in vaccinated compared to boostered (Ct, 23.14) individuals (P = .029). However, by performing a longitudinal analysis on 32 individuals over 14 days, no difference in the viral load trajectory was observed between double-vaccinated and boostered patients. Our results indicate that booster immunization results in a reduction in detectable viral loads without significantly changing viral load dynamics over time. This study provides longitudinal data upon Omicron breakthrough infections in double-vaccinated and boostered individuals. While peak viral loads were reduced in boostered individuals, no difference was observed for the duration of SARS-CoV-2 detection between both groups.

Automated summary

This study provides longitudinal data on the viral dynamics of Omicron breakthrough infections in individuals who received two doses or booster shots of the vaccine. The results indicate that booster immunization reduces detectable viral loads without significantly altering viral load dynamics over time.