The effect of sleep and shift work on the primary immune response to messenger <scp>RNA</scp> ‐based <scp>COVID</scp> ‐19 vaccination

Shift work can cause circadian misalignment, which often results in sleeping problems and has been associated with immune dysfunction. To better understand the impact of shift work on a primary immune response to vaccination, we compared severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2)-specific humoral and cellular immune responses after one injection of the messenger RNA (mRNA)-1273 vaccine between day workers (n = 24) and night shift workers (n = 21). In addition, duration and quality of sleep were assessed for a period of 7 days around the time of vaccination using actigraphy and daily sleep diaries, and their relationship with immunogenicity of mRNA-1273 vaccination was studied. We found that median total sleep time on the 2 days immediately after vaccination, which coincided with the days that night shift workers worked night shifts, was significantly lower in night shift workers (342 and 318 min) than day workers (431 and 415 min) (both p < 0.001). There was no difference in sleep quality between day workers and night shift workers. Furthermore, no difference in the antibody response between the two groups was observed, yet night shift workers had a significantly higher virus-specific T-cell response than day workers 28 days after immunisation (p = 0.013). Multivariate regression analysis showed no association between sleep duration, sleep quality and SARS-CoV-2-specific humoral or cellular immune responses. Collectively, these findings indicate that shift work-induced sleep loss and night shift work have little to no effect on the primary immune response to mRNA-based COVID-19 vaccination.