Team of Sun Yat sen University: SARS virus antibody can exist for a long time

Author: up to now, the new coronal pneumonia virus (sars-cov-2) has caused more than 70000 confirmed cases in China In view of the high similarity between sars-cov-2 and SARS-CoV 17 years ago Therefore, the information about SARS CoV is also valuable for the prevention and control of the current epidemic In a paper published on the preprint website medrxiv (without peer review) on February 15, Lu Jiahai's team from school of public health, Sun Yat sen University published relevant research In 2002, SARS broke out in Guangdong Province of China for the first time, then became a pandemic, and spread rapidly to 31 countries and regions, causing global panic and public health crisis According to the data released by the World Health Organization, the total number of SARS cases is 8422, and the fatality rate is 10.88% (916 / 8422) Guangdong Province is one of the most seriously affected provinces A total of 1511 cases were reported, 22.90% (346 / 1511) of which occurred among medical staff They were infected during the early stages of the outbreak when they treated and cared for SARS patients In the later stage of the outbreak, although the preventive measures against infection were strengthened, there were still medical staff infected SARS CoV was first identified in 2003 as a result of cross species transmission from small carnivores (if beavers) to humans Recent studies have shown that SARS CoV may originate from bats Bat coronavirus isolates have been shown to recognize ACE2 receptors in humans and bats Coronaviruses can take advantage of many cellular receptors and can cause various diseases, such as respiratory and gastrointestinal diseases In particular, spike protein is an important determinant of virus receptor interaction, cross species transmission and host tendency, and its mutation can promote cross species to interpersonal transmission In 2012, the Middle East respiratory syndrome coronavirus (mers COV) appeared in the Middle East Mers cov has been shown to infect humans from camels, highlighting the continuing threat posed by SARS CoV or SARS like coronavirus SARS CoV IgG antibody has neutralization activity and provides protection from infection The presence of antiviral and nucleocapsid IgG antibodies represents a protective immune response Although some previous studies have reported the longitudinal changes of SARS IgG antibody for up to five years, there is a lack of understanding of humoral immune response in a longer period of time In this study, the team conducted a 13-year follow-up study on a group of medical staff who were infected with SARS CoV in the same year to analyze the existence and persistence of anti SARS CoV antibodies The researchers collected a total of 362 serum samples, including those collected from all study participants when they were admitted to the hospital in 2003, as well as those collected annually when the participants participated in the annual physical examination (April to June 2004 to 2015) In addition, serum samples of another 20 subjects were collected from 95 SARS cases in 2015, and 40 non infected medical staff from the same hospital were selected as the control group, and serum samples were collected to verify the final result data of 34 medical queues infected by SARS CoV in 2015 Using the intact virus and SARS CoV recombinant nucleocapsid protein as diagnostic antigens, the researchers tested all sera for IgG antibodies by ELISA The results showed that the anti SARS CoV IgG could last for more than 12 years IgG titer usually peaked in 2004, declined rapidly between 2004 and 2006, and then continued to decline at a slower rate Until 2015, the IgG titer of medical staff infected with SARS CoV remained at a significantly higher level At the time of infection, the IgG of patients receiving corticosteroid treatment was lower than that of uninfected patients Lu Jiahai, a professor at the school of public health, Sun Yat sen University and the study's corresponding author, said: "that is to say, the high-dose or long-term use of hormones may affect the immune system of patients and lead to the decline of immunity." Based on the above results, the team concluded that SARS covigg antibody can last for at least 12 years and may have protective effects on SARS CoV and other β - coronaviruses This study provides valuable information for the humoral immune response of SARS-CoV and sars-cov-2 "Because sars-cov-2 and SARS-CoV are both coronaviruses, if the vaccine against sars-cov-2 is successfully developed, its immune protection may last for more than 10 years," lujiahai said At the same time, we speculate that there is a cross protective effect of SARS CoV antibody on sars-cov-2, which needs further study and confirmation " Long term persistence of IgG antibiotics in SARS CoV infected healthcare workers doi: 10.1101/2020.02.12.20021386