“The protection against COVID-19 tends to decline over time after vaccination,” the researchers wrote in the journal Nutrients. “This study showed the potential of KRG for boosting immunity and helping maintain a higher vaccine-induced humoral response after COVID-19 vaccination.”
The study tracked 350 healthy subjects who received two initial doses of the COVID-19 vaccine and a booster over a 24-week study period to examine the effect of KRG on virus-specific antibodies following vaccination.
KRG as immunomodulator
Derived from Panax ginseng C.A. Meyer, KRG has shown itself to be an effective immunomodulating agent that increases recovery rates and reduced mortality from viral infections, boosts protective effects against infections including influenza, and defends against acute respiratory illness.
Previous evidence also suggests that KRG can improve vaccine efficacy by inhibiting reactive oxygen species production and improving antibody formation after influenza vaccination.
“However, no study has examined whether KRG affects COVID-19 vaccine-induced immune response and protection,” the researchers noted, adding that there is growing interest in natural immunomodulators that enhance host immunity in the vaccinated population.
Study details
The study allocated 350 adults over the age of 30 to either a KRG group (149 individuals who had taken red ginseng for at least one month prior to vaccination) or to a control group (201 individuals who had not taken red ginseng for a minimum of two months prior to vaccination). Participants in the KRG group consumed one 3 g tablet of KRG a day for four weeks leading up to the study period.
There were baseline differences in age, sex, aspartate aminotransferase, and vitamin D between the two groups but no difference in fasting plasma glucose, lipid profiles, alanine aminotransferase, and immunoglobulin E. Both groups registered similar body mass index and hypertension measures.
The study evaluated antibody response at five intervals: just before the second dose (baseline); at two, four and 12 weeks after the second dose; and at four weeks after the third dose. The primary endpoints were changes in COVID-19 spike antibody titers and neutralizing antibody titers.
Vaccine-induced humoral immune responses in both the KRG and control groups increased significantly after the first vaccination and for two weeks after the second dose, decreasing through the 12 weeks leading up to the booster, when levels spiked again.
“The antibody formation rate of the KRG group was sustained higher than that of the control group for 12 weeks after the second dose,” the study concluded. “This trend was prominently observed in those above 50 years old.”
To explain the extended response in the KRG group, the study pointed to KRG's potential role in the regulation of cytokines and chemokines (critical factors in innate immunity and inflammation) and an increase in immune cell proliferation and activity.
The researchers called for further research into the mechanisms behind KRG effects on the upregulation of T cells, B cells and cytokines after COVID-19 vaccination.
Source: Nutrients 2023, 15(7), 1584
“Korean Red Ginseng Potentially Improves Maintaining Antibodies after COVID-19 Vaccination: A 24-Week Longitudinal Study”
doi: doi.org/10.3390/nu15071584
Authors: Jihyun Yoon et al.