Four different endemic coronaviruses (eCoVs) are etiologic agents for the seasonal common cold, and these eCoVs share extensive sequence homology with human SARS coronavirus 2 (SARS-CoV-2). Here, we show that individuals with, as compared with those without, a recent documented infection with eCoV were tested at greater frequency for respiratory infections but had a similar rate of SARS-CoV-2 acquisition. Importantly, the patients with a previously detected eCoV had less-severe coronavirus disease 2019 (COVID-19) illness. Our observations suggest that preexisting immune responses against endemic human coronaviruses can mitigate disease manifestations from SARS-CoV-2 infection.
Manish Sagar, Katherine Reifler, Michael Rossi, Nancy S. Miller, Pranay Sinha, Laura F. White, Joseph P. Mizgerd
Submitter: JOSE R. SECO VASCO | joser.seco.sspa@juntadeandalucia.es
Authors: JOSE R. SECO VASCO, RAUL CURADO CASTANO, ANA M. MATEOS GOMEZ, RUBEN RUIZ-MATEOS QUIROS, CARMEN GARCIA GARROTE.
SCCU SEVILLA SUR. HOSPITAL DE VALME. SERVICIO ANDALUZ DE SALUD. SPAIN.
Published November 16, 2020
A better understanding of the evolution of current COVID-19 pandemic, and thus a substantial improvement in its management, will require a significant increase in the knowledge of immune response to SARS-CoV-2 infection. It has been shown that cell-mediated immunity plays an important role in such a response1. In their remarkable work, M. Sager et al. suggest that pre-existing immune responses against endemic coronaviruses (eCoVs) may influence clinical evolution in patients subsequently infected by SARS-CoV-2. Inversely, it may be expected that COVID-19 patients show cross-reactivity with similar targets present in different eCoVs. For those interactions we can see a potential link to T cell function, which has been invoked as a determinant of COVID-19 outcome, and even used as a successful treatment in some severe cases2. Suggested cross-immunity for eCoVs could also have meaningful clinical implications, although more evidence is needed. For instance, a previous eCoVs infection could be a possible protective factor to be considered in long-term follow-up of COVID-19 patients, even those recovered. Moreover, to a certain extent, T cell function and previous individual exposure or eCoVs infections could explain why a large number of infected people remains asymptomatic, as well as the fact that highly exposed individuals do not necessarily become infected by SARS-CoV-23. The consequences in terms of public health are potentially significant, since current prevalence data are mostly based on serological testing, but do not take into account those patients who have developed a cellular response by other means4, nor those previously exposed and immunized to other eCoVs, as can be inferred from results of this interesting work. Actual prevalence of immunity to SARS-CoV-2 could be much larger than previously estimated5, although it is still too early to assess the real influence of these dynamics on the pandemic.
1. Carolyn Rydyznski Moderbacher, Sidney I. Ramirez, Jennifer M. Dan, Alba Grifoni, Kathryn M. Hastie, Daniela Weiskopf et al. Antigen-Specific Adaptive Immunity to SARS-CoV-2 in Acute COVID-19 and Associations with Age and Disease Severity. Cell 183, 1–17 November 12, 2020. https://doi.org/10.1016/j.cell.2020.09.038
2. José R. Seco Vasco, Raúl Curado Castano. An increasing role of cell-mediated immunity in multidimensional treatment for COVID-19. Comment to Douglas E. Gladstone, Bo S. Kim, Kathy Mooney, Andrew H. Karaba, and Franco R. D'Alessio. Regulatory T Cells for Treating Patients With COVID-19 and Acute Respiratory Distress Syndrome: Two Case Reports. Annals of Internal Medicine 6 July, 2020. https://doi.org/10.7326/L20-0681
3. Marina Pollán, Beatriz Pérez-Gómez, Roberto Pastor-Barriuso, Jesús Oteo, Miguel A. Hernán, Mayte Pérez-Olmeda et al. Prevalence of SARS-CoV-2 in Spain (ENE-COVID): a nationwide, population-based seroepidemiological study. The Lancet. 2020; 396(10250) : 535-544 https://doi.org/10.1016/S0140-6736(20)31483-5
4. Doshi P. Covid-19: Do many people have pre-existing immunity?. British Medical Journal. 2020; 370 :m3563 https://doi.org/10.1136/bmj.m3563
5. Francesca Bassi, Arbia Giuseppe, Pietro D. Falorsi. Observed and estimated prevalence of Covid-19 in Italy: How to estimate the total cases from medical swabs data. Science of The Total Environment. 2020:142799. https://doi.org/10.1016/j.scitotenv.2020.142799