New research from scientists at La Jolla Institute for Immunology (LJI) suggests people who received COVID-19 vaccines and then experienced "breakthrough" infections are especially well armed against future SARS-CoV-2 infections.
By analyzing blood samples from study volunteers, the LJI researchers discovered that people who experienced symptomatic breakthrough infections develop T cells that are better at recognizing and targeting SARS-CoV-2, including the Omicron and Delta variants. The researchers describe this increased protection as an "immunity wall."
Key findings:
Study volunteers who experienced symptomatic breakthrough infections developed T cells that recognized multiple targets on the SARS-CoV-2 viral "Spike" and non-Spike epitopes.
This infection left study volunteers with T cells that were better equipped to recognize mutated regions on new SARS-CoV-2 variants.
Even asymptomatic breakthrough infections boost T cell responses, though the effect was not as significant.
Breakthrough infections also led B cells to produce cross-reactive antibodies against SARS-CoV-2. Most of these antibodies targeted the new viral variants and the original vaccine antigens.
The researchers found no evidence of harmful "T cell exhaustion" in study volunteers who had experienced repeated COVID-19 vaccinations and SARS-CoV-2 infections.
