|LETTER TO EDITOR
|Year : 2020 | Volume
| Issue : 9 | Page : 5074-5075
Immune response in SARS-CoV-2
Antonio Luis Aguilar-Shea1, Cristina Gallardo Mayo2
1 Centro de Salud Puerta de Madrid, Atención Primaria de Madrid, Madrid, Spain
2 Anesthesiology and Reanimation, Hospital Infanta Leonor, Madrid, Spain
|Date of Submission||27-Jul-2020|
|Date of Decision||03-Sep-2020|
|Date of Acceptance||18-Aug-2020|
|Date of Web Publication||30-Sep-2020|
Dr. Antonio Luis Aguilar-Shea
A.P. Puerta de Madrid, Avda del Ejercito 61, 28802 Alcala de Henares, Madrid
Source of Support: None, Conflict of Interest: None
|How to cite this article:|
Aguilar-Shea AL, Mayo CG. Immune response in SARS-CoV-2. J Family Med Prim Care 2020;9:5074-5
To the editor,
We have read with great interest the recently published article from Sahu AK et al. COVID-19 currently has no treatment and no preventive vaccine, so efforts to control the disease are based on quarantine, social distance, and cleaning. Serological assays to detect antibodies have become available to estimate the real prevalence of the pandemic, including those that relevant percentage of asymptomatic., COVID-19 pandemic has become the greatest health challenge worldwide of the last century, only comparable to the H1N1 flu pandemic from 1918; it has been the sixth global public health emergency after H1N1 (2009), Polio (2014), Ebola in West Africa (2014), Zika (2016), and Ebola in the Democratic Republic of Congo (2019). At this point of the pandemic, understanding the immunity is important for the future approach of the vaccination strategies, which is the next big step in the fight against the virus.
Coronaviruses are not unknown to humanity, four of these (HCoV-NL63, HCoV-229E, HCoV-OC43, and HKU1) cause mild common cold symptoms and other two caused epidemics, severe acute respiratory syndrome coronavirus (SARS-CoV) in 2002-2003 and Middle East respiratory syndrome coronavirus (MERS-CoV) in 2012. All of them are zoonotic infections and have a rodent or bat origin.
Coronaviruses are known for having a “correcting” enzyme (exoribonuclease) that corrects errors in the RNA sequence giving stability to the virus genome and by this, limiting mutations. Current SARS-CoV-2 is 96% identical at the genome level to a previously detected bat coronavirus, which belongs to a SARS-related coronavirus species (i.e., SARS-CoV)., Recent analysis of the SARS-CoV-2 virus strains showed 3 main types: type A, the original virus that jumped to humans from bats via pangolins and the most prevalent in Australia and the US, type B the most prevalent in China and part of Europe, and type C, descended from type B and that spread to Europe via Singapore. These 3 strain types are very similar to one another.
The theories why COVID-19 has a milder presentation and significantly lower mortality in children are: (1) the quality and/or quantity difference in the virus cell receptor (ACE2 protein), (2) the less underlying comorbid conditions at that age, (3) the greater population of naïve T-cells, which are key in the immune response for the formation of the specific neutralizing antibodies and cell-mediated immune response, and (4) some cross protection from antibodies from past infections of other coronavirus responsible for common colds, with more incidence during the early years of life.
As today, no reinfection from SARS-CoV-2 has been proven and added to the fact that the virus corrects errors in its RNA limiting mutations, it gives us optimism to definitely end this pandemic with the vaccine and effective immunization programs. Also, if some type of cross protection immunity is confirmed it will give humanity protection against future coronavirus infections.
Financial support and sponsorship
Conflicts of interest
There are no conflicts of interest.
| References|| |
Sahu AK, Nayer J, Aggarwal P. Novel coronavirus: A capsule review for primary care and acute care physicians. J Family Med Prim Care 2020;9:1820-4. [Full text]
Kirkcaldy RD, King BA, Brooks JT. COVID-19 and postinfection immunity: limited evidence, many remaining questions. JAMA 2020. doi: 10.1001/jama.2020.7869.
Bergmann CC, Silverman RH. COVID-19: Coronavirus replication, pathogenesis, and therapeutic strategies. Cleve Clin J Med 2020. doi: 10.3949/ccjm.87a.20047.
Rabi FA, Al Zoubi MS, Kasasbeh GA, Salameh DM, Al-Nasser AD. SARS-CoV-2 and coronavirus disease 2019: What we know so far. Pathogens 2020;9:E231.
Li X, Wang W, Zhao X, Zai J, Zhao Q, Li Y, et al
. Transmission dynamics and evolutionary history of 2019-nCoV. J Med Virol 2020;92:501-11.
Forster P, Forster L, Renfrew C, Forster M. Phylogenetic network analysis of SARS-CoV-2 genomes. Proc Natl Acad Sci U S A 2020;117:9241-3.
Ahmadpoor P, Rostaing L. Why the immune system fails to mount an adaptive immune response to a COVID-19 infection. Transpl Int 2020;33:824-5.