[ad_1]
Coronavirus disease 2019 (COVID-19), which is caused by infection with the highly contagious severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has been diagnosed in almost 600 million people worldwide and has caused almost 6.5 million deaths . Although the role of the humoral immune response against SARS-CoV-2 infection is well understood, the duration of protection after infection has not yet been determined.
survey: Two-year antibody responses after SARS-CoV-2 infection in humans: Study protocol. Image credit: Cryptographer / Shutterstock.com
Background
Several studies have shown that a significant increase in antibody levels against SARS-CoV-2 occurs between 16th and 35th day after the onset of symptoms. These antibody levels remain high for the first few months after recovery from COVID-19, then decline and remain stable for the next few months.
This finding indicates the possibility of immune protection for a longer period. In fact, SARS-CoV-2-specific immunoglobulin G (IgG) levels have been reported to persist for six to eight months, after which they disappear.
A detailed immunological screening of patients with COVID-19 showed that in most cases the levels of anti-SARS-CoV-2 receptor binding domain (RBD) and spike (S) IgG increased between 15 and 28 days after the onset of symptoms. After that, there is a gradual decline in antibody levels for up to six months and then remains stable for the next fifteen months. This study also detected SARS-CoV-2-specific IgM on day seven, which peaked on day 28th day.
Another factor that affects antibody levels is the severity of the disease. Similar to other coronaviruses, such as Middle East respiratory syndrome coronavirus (MERS-CoV) and SARS-CoV, seroconversion rates and antibody levels increase with disease severity.
There remains a need to develop an appropriate disease prevention model for the general population. This will require an appropriate monitoring system that can accommodate data from hundreds of respondents.
In a recent FLOOR ONE journal study, scientists describe a protocol to assess the dynamics of the antibody response up to two years after infection with SARS-CoV-2. Here, the authors also assess the protective and risk factors associated with COVID-19 that are prevalent in the community.
The study protocol
A three-year ongoing research project began enrolling patients in January 2021. The first two years will focus on participant enrollment, screening and laboratory analysis, while findings will be disseminated in the third year.
The present study included a prospective cohort study and a case-control study. To determine the kinetics of the anti-SARS-CoV-2 antibody over two years, in relation to the severity of the disease, the scientists adapted a prospective observational method.
In contrast, the case-control study determined the risk and protective factors associated with COVID-19. Specifically, this study compared patients with confirmed SARS-CoV-2 infection (case group) with individuals in their respective neighborhoods (control group).
The scientists focused on developing a cohort system to manage the COVID-19 pandemic. This includes longitudinal population and hospital data that were collected from Sleman District, Indonesia.
Survey results
Case study participants were recruited from the Universitas Gadjah Mada (UGM) Academic Hospital in Yogyakarta. For each confirmed case of COVID-19, three uninfected control candidates who lived within a one-kilometer (km) radius of the infected person’s residence were recruited, totaling 165 patients with COVID-19 and 495 healthy controls.
It is hypothesized that travel patterns, community structure, and individual behaviors such as adherence to health protocols and sleep patterns are important determinants of the spread of COVID-19. To evaluate this hypothesis, detailed demographic data on community variables, including contact history and environmental density, as well as behavior, comorbidities, pregnancy, anthropometric parameters, and vaccination status against COVID-19, were collected from medical records and face-to-face interviews.
Anti-SARS-CoV-2 IgM/IgG levels have been suggested to correlate with disease severity. To test this hypothesis, quantification of peripheral blood IgM/IgG anti-S RBD titers was measured using a chemiluminescent microparticle immunoassay (CMIA).
Conclusions
It is important to examine the levels of antibodies against SARS-CoV-2 in a given population, as this indicator can provide insight into past and current infections. In addition, these data will aid in the study of antibody-mediated protective immunity and the immunopathology of COVID-19.
The current study design may help determine unknown rates of seroconversion and seroreversion in hospitalized patients. Estimating the time required for seroconversion can help predict disease severity.
One of the limitations of the present study is related to its longitudinal design, which requires maintaining the entire cohort for the entire study period. Thus, there is a risk of decreasing the willingness of applicants to continue participating in the study over time.
To overcome this challenge, scientists offer incentives such as free basic medical examinations after each follow-up visit. Because of accessibility issues, the researchers adopted a low-cost screening method for the controls that involved breath print analyzes of the patients rather than the nucleic acid amplification test (NAAT).
The results of the study will offer better insight into the populations at risk of COVID-19, as well as the duration of immune protection.
Journal reference:
- Arguni, E., Dewey, FST, Fachiroh, J. et al. (2022) Two-year antibody responses following SARS-CoV-2 infection in humans: Study protocol. FLOOR ONE 17(8): e0272690. doi:10.1371/journal.pone.0272690.
[ad_2]
Source link