Modulation of host immune response by supplementation of palm vitamin E and carotenoids: Elucidating the mechanisms of action using a mouse model of COVID-19 vaccination

The coronavirus disease 2019 (COVID-19), caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), results in substantial morbidity and mortality. To induce robust and long-lasting immunity, the demand for vaccine has never been more apparent. Besides the pharmaceutical approach, a nutraceutical approach using tocotrienol-rich fraction (TRF) and carotene supplements can potentially enhance the host immune system. In this study, we investigated the immunomodulatory effects of TRF and carotene supplementations in 10-weeks-old male BALB/c mice vaccinated with the inactivated SARS-CoV 2 vaccine to understand the correlation between their immunomodulatory effects and modulation of gut microbiota modulation in the supplemented mice.