The following is a summary of “Vaccination Ameliorates Cellular Inflammatory Responses in SARS-CoV-2 Breakthrough Infections,” published in the July 2023 issue of Infectious Diseases by Huapaya, et al.
There was limited data on cellular immune responses in individuals who experience breakthrough infections of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) following vaccination. Evaluating the cases can provide valuable insights into how vaccinations mitigate harmful inflammatory responses in the host.
The prospective study examined the peripheral blood cellular immune responses to SARS-CoV-2 infection in 21 vaccinated patients with mild disease and 97 unvaccinated patients, categorized based on the severity of their infection.
A total of 118 individuals with SARS-CoV-2 infection participated in the study. Among the vaccinated patients with breakthrough infections, there was a higher percentage of antigen-presenting monocytes (HLA-DR+), mature monocytes (CD83+), functionally competent T cells (CD127+), and mature neutrophils (CD10+). Conversely, vaccinated patients had lower percentages of activated T cells (CD38+), activated neutrophils (CD64+), and immature B cells (CD127+CD19+) when compared to unvaccinated patients. The differences in immune responses between the two groups were more pronounced in unvaccinated patients with more severe disease. The longitudinal analysis demonstrated decreased cellular activation over time, although it persisted in unvaccinated patients with mild disease even at the 8-month follow-up.
Individuals with SARS-CoV-2 breakthrough infections display cellular immune responses that help restrict the escalation of inflammatory responses, indicating how vaccination can limit the severity of the disease. The findings have potential implications for the development of more effective vaccines and therapies to combat SARS-CoV-2.