The COVID-19 vaccines have been hailed as a crucial tool in the fight against the pandemic. They have been touted for their ability to stimulate an immune response and protect individuals from severe illness and hospitalization. However, recent findings suggest that these vaccines may have some unintended consequences on our cellular immunity, particularly T-cell immunity.
A study published in Frontier Immunology examined the long-term impact of the COVID-19 mRNA vaccine on cellular immunity. The study tracked the immune responses of 61 subjects who received five doses of the vaccine over a period of two years. The researchers found that while most patients maintained a strong antibody response, their cellular immunity weakened in many cases, especially after the fifth vaccine booster dose. Older participants were more likely to have a slightly weaker cellular immune response.
Cellular immunity, also known as cell-mediated immunity, does not involve antibodies and is crucial in preventing the severe form of COVID-19. It is executed by specialized immune cells such as T cells, B cells, and natural killer cells. T cells play a critical role in coordinating the immune response and destroying infected cells. However, the study found that extended vaccination impaired the amount and efficacy of serum RBD-specific antibodies, as well as shortened long-term humoral memory.
These findings raise concerns about the potential risks associated with continued use of SARS-CoV-2 boosters. It is important to understand the importance of cellular immunity in fighting off infections. Our immune system consists of natural immunity and adaptive immunity, with the latter relying on specialized immune cells to respond to specific viruses. Studies have shown that new variants of SARS-CoV-2 can evade the immune response created by mRNA vaccines but cannot escape T-cell-associated defense.
Interferon, a powerful antiviral weapon, plays a pivotal role in both mucosal immunity and cellular immunity. It helps eradicate viruses at the frontline when produced naturally via our mucosa. However, injected vaccinations do not allow for this natural production of interferon. Moreover, the spike protein in mRNA vaccines has been found to dysregulate our normal antiviral immunity and impair interferon responses and cellular immunity.
Other factors that may contribute to the weakening of cellular immunity include the use of modified mRNA, lipid nanoparticles present in the vaccine, potential blood vessel injury caused by antibodies targeting spike proteins, and the phenomenon of antibody-dependent enhancement. Additionally, new variants like Omicron have learned to mutate in non-spike regions, making it more challenging for our original T-cell immunity to eradicate them.
