tetano
Editor, Senior Moderator
J Clin Immunol
. 2024 Jun 10;44(6):147.
doi: 10.1007/s10875-024-01739-0. Lower Humoral and Cellular Immunity Following Asymptomatic SARS-CoV-2 Infection Compared to Symptomatic Infection in Education (The ACE Cohort)
Georgina Hopkins[SUP] 1 [/SUP], Nancy Gomez[SUP] 1 [/SUP], Davis Tucis[SUP] 1 [/SUP], Laura Bartlett[SUP] 1 [/SUP], Graham Steers[SUP] 1 [/SUP], Ellie Burns[SUP] 1 [/SUP], Michaela Brown[SUP] 1 [/SUP], Tyler Harvey-Cowlishaw[SUP] 1 [/SUP], Rute Santos[SUP] 1 [/SUP], Sarah N Lauder[SUP] 2 [/SUP], Martin Scurr[SUP] 2 3 [/SUP], Lorenzo Capitani[SUP] 2 [/SUP], Stephanie Burnell[SUP] 2 [/SUP], Tara Rees[SUP] 2 [/SUP], Kathryn Smart[SUP] 2 [/SUP], Michelle Somerville[SUP] 2 [/SUP], Awen Gallimore[SUP] 2 [/SUP], Marianne Perera[SUP] 4 [/SUP], Martin Potts[SUP] 4 [/SUP], Marina Metaxaki[SUP] 4 [/SUP], Benjamin Krishna[SUP] 4 [/SUP], Hannah Jackson[SUP] 1 [/SUP], Paddy Tighe[SUP] 1 [/SUP], David Onion[SUP] 1 [/SUP], Andrew Godkin[SUP] 2 3 [/SUP], Mark Wills[SUP] 4 [/SUP], Lucy Fairclough[SUP] 5 [/SUP]
Affiliations
Purpose: Asymptomatic SARS-CoV-2 infections were widely reported during the COVID-19 pandemic, acting as a hidden source of infection. Many existing studies investigating asymptomatic immunity failed to recruit true asymptomatic individuals. Thus, we conducted a longitudinal cohort study to evaluate humoral- and cell-mediated responses to infection and vaccination in well-defined asymptomatic young adults (the Asymptomatic COVID-19 in Education [ACE] cohort).
Methods: Asymptomatic testing services located at three UK universities identified asymptomatic young adults who were subsequently recruited with age- and sex-matched symptomatic and uninfected controls. Blood and saliva samples were collected after SARS-CoV-2 Wuhan infection, and again after vaccination. 51 participant's anti-spike antibody titres, neutralizing antibodies, and spike-specific T-cell responses were measured, against both Wuhan and Omicron B.1.1.529.1.
Results: Asymptomatic participants exhibited reduced Wuhan-specific neutralization antibodies pre- and post-vaccination, as well as fewer Omicron-specific neutralization antibodies post-vaccination, compared to symptomatic participants. Lower Wuhan and Omicron-specific IgG titres in asymptomatic individuals were also observed pre- and post-vaccination, compared to symptomatic participants. There were no differences in salivary IgA levels. Conventional flow cytometry analysis and multi-dimensional clustering analysis indicated unvaccinated asymptomatic participants had significantly fewer Wuhan-specific IL-2 secreting CD4[SUP]+[/SUP] CD45RA[SUP]+[/SUP] T cells and activated CD8[SUP]+[/SUP] T cells than symptomatic participants, though these differences dissipated after vaccination.
Conclusions: Asymptomatic infection results in decreased antibody and T cell responses to further exposure to SARS-CoV-2 variants, compared to symptomatic infection. Post-vaccination, antibody responses are still inferior, but T cell immunity increases to match symptomatic subjects, emphasising the importance of vaccination to help protect asymptomatic individuals against future variants.
Keywords: Antibody; Asymptomatic; SARS-CoV-2; Symptomatic; T cells; Vaccination.
. 2024 Jun 10;44(6):147.
doi: 10.1007/s10875-024-01739-0. Lower Humoral and Cellular Immunity Following Asymptomatic SARS-CoV-2 Infection Compared to Symptomatic Infection in Education (The ACE Cohort)
Georgina Hopkins[SUP] 1 [/SUP], Nancy Gomez[SUP] 1 [/SUP], Davis Tucis[SUP] 1 [/SUP], Laura Bartlett[SUP] 1 [/SUP], Graham Steers[SUP] 1 [/SUP], Ellie Burns[SUP] 1 [/SUP], Michaela Brown[SUP] 1 [/SUP], Tyler Harvey-Cowlishaw[SUP] 1 [/SUP], Rute Santos[SUP] 1 [/SUP], Sarah N Lauder[SUP] 2 [/SUP], Martin Scurr[SUP] 2 3 [/SUP], Lorenzo Capitani[SUP] 2 [/SUP], Stephanie Burnell[SUP] 2 [/SUP], Tara Rees[SUP] 2 [/SUP], Kathryn Smart[SUP] 2 [/SUP], Michelle Somerville[SUP] 2 [/SUP], Awen Gallimore[SUP] 2 [/SUP], Marianne Perera[SUP] 4 [/SUP], Martin Potts[SUP] 4 [/SUP], Marina Metaxaki[SUP] 4 [/SUP], Benjamin Krishna[SUP] 4 [/SUP], Hannah Jackson[SUP] 1 [/SUP], Paddy Tighe[SUP] 1 [/SUP], David Onion[SUP] 1 [/SUP], Andrew Godkin[SUP] 2 3 [/SUP], Mark Wills[SUP] 4 [/SUP], Lucy Fairclough[SUP] 5 [/SUP]
Affiliations
- PMID: 38856804
- DOI: 10.1007/s10875-024-01739-0
Purpose: Asymptomatic SARS-CoV-2 infections were widely reported during the COVID-19 pandemic, acting as a hidden source of infection. Many existing studies investigating asymptomatic immunity failed to recruit true asymptomatic individuals. Thus, we conducted a longitudinal cohort study to evaluate humoral- and cell-mediated responses to infection and vaccination in well-defined asymptomatic young adults (the Asymptomatic COVID-19 in Education [ACE] cohort).
Methods: Asymptomatic testing services located at three UK universities identified asymptomatic young adults who were subsequently recruited with age- and sex-matched symptomatic and uninfected controls. Blood and saliva samples were collected after SARS-CoV-2 Wuhan infection, and again after vaccination. 51 participant's anti-spike antibody titres, neutralizing antibodies, and spike-specific T-cell responses were measured, against both Wuhan and Omicron B.1.1.529.1.
Results: Asymptomatic participants exhibited reduced Wuhan-specific neutralization antibodies pre- and post-vaccination, as well as fewer Omicron-specific neutralization antibodies post-vaccination, compared to symptomatic participants. Lower Wuhan and Omicron-specific IgG titres in asymptomatic individuals were also observed pre- and post-vaccination, compared to symptomatic participants. There were no differences in salivary IgA levels. Conventional flow cytometry analysis and multi-dimensional clustering analysis indicated unvaccinated asymptomatic participants had significantly fewer Wuhan-specific IL-2 secreting CD4[SUP]+[/SUP] CD45RA[SUP]+[/SUP] T cells and activated CD8[SUP]+[/SUP] T cells than symptomatic participants, though these differences dissipated after vaccination.
Conclusions: Asymptomatic infection results in decreased antibody and T cell responses to further exposure to SARS-CoV-2 variants, compared to symptomatic infection. Post-vaccination, antibody responses are still inferior, but T cell immunity increases to match symptomatic subjects, emphasising the importance of vaccination to help protect asymptomatic individuals against future variants.
Keywords: Antibody; Asymptomatic; SARS-CoV-2; Symptomatic; T cells; Vaccination.