SpaceX study profiles evolution of antibody response during COVID-19 infection

New research published on preprint server bioRxiv* S2-specific antibody response suggests that it is important for recovery from mild to severe COVID-19 infection. Patients with a wide range of S2-specific responses were more likely to survive than those who died within 28 days of COVID-19 diagnosis.

The data also show that previous exposure to others Coronavirus For example, OC43, which causes colds — provides early cross-immunity and helps protect the body from SARS-CoV-2 infections.

Data collection from mild and asymptomatic COVID-19 infection

SpaceX employees volunteered for the COVID-19 test in mid-April 2020 without exclusion criteria.Participants have completed a survey on COVID19 Symptoms Blood samples were then collected every 39.7 days.

Researchers, including SpaceEx’s Elon Musk, categorized each COVID-19 symptom into level 0 to moderate symptom level 2.

Collecting data on moderate to severe infections

The study recruited 384 patients with acute respiratory distress and other COVID-19 symptoms between March 24, 2020 and April 30, 2020. Approximately 217 people were positive by PCR at the hospital 0-12 days after experiencing the symptoms.

Patients were divided into three groups. The first group were patients of moderate severity who required hospitalization and oxygen support but were not on ventilator. The second group was patients with severe COVID-19 infection who needed intubation but survived for at least 28 days. The final group consisted of 42 patients who died within 28 days.

Researchers characterized a humoral immune response to SARS-CoV-2 during the first 12 days of onset of symptoms.

Immune response during initial infection

The results showed a significant reduction in receptor-binding domains, complete S proteins, S2 subunits, and IgG1 specific for N-specific antibodies during initial infection. Decreased SARS-CoV-2 specific IgG3, IgA1 titers, and FcγR binding capacity were also observed.

Patients who did not survive showed S2-specific decreased IgM levels 3-9 days after onset of symptoms. It also lacked the FcγR binding capacity required to neutralize the coronavirus.

Strong antibody production in the early stages of infection (approximately 0-3 days after onset of symptoms) was more common in patients with severe COVID-19 disease than in non-surviving patients.

Increased immune response targeting the SARS-CoV-2S2 domain

There were six immune response differences between patients who survived COVID-19 infection and those who did not — 4 of the 6 survivors involved targeted the S2 domain of SARS-CoV-2. We have developed an Fc receptor-binding antibody.

Patients with severe infections also developed more S2-specific IgG4 immune responses in all groups. Findings show that S2-specific immunity is the key to recovery from COVID-19 disease.

“These data highlight a uniquely emanating S2-specific Fc profile that represents a major early biomarker that clearly distinguishes survivors and non-survivors of COVID-19,” the researchers conclude. I did.

Pre-exposure to other coronaviruses aids immunity

Next, researchers investigated the mechanism behind the enhancement of S2-specific immunity. They hypothesized that the response could result from rapid maturation of the humoral immune response or cross-immunity with other coronaviruses.

Beta coronavirus OC43 is so prevalent in the United States that it has received a lot of attention. They profiled antibody responses targeting the OC43 receptor-binding domain and evaluated how they affect SARS-CoV-2 immunity.

The results showed that patients who survived severe or moderate COVID-19 infection had higher levels of OC43 receptor-binding domain-specific IgM and IgG1 3-6 days after symptom. .. No differences were observed for IgA, IgG3 levels, or Fc receptor binding.

Patients with severe illness showed higher OC43-specific IgG1 levels than patients with moderate illness.

IgM antibody levels specific for the OC43 receptor-binding domain were significantly higher than in patients who did not survive COVID-19.

The OC43-specific immune response of COVID-19 survivors also expanded to target coronavirus. Spike protein, S1 subunit, S2 subunit, and nucleocapsid.

The results show that prior immunity to beta-coronavirus OC43 enhances cross-immunity to SARS-CoV-2.

An increase in the OC43 immune response appeared early in the infection but did not progress during treatment. The response diminished after 3 days, suggesting that humoral immunity specifically targeting SARS-CoV-2 has matured over time.

S2-specific antibodies observed during mild COVID-19 infection

Asymptomatic patients with COVID-19 showed strong OC43-specific IgA and IgG responses. Patients with mild symptoms responded similarly.

OC43-specific IgG1 increased after SARS-CoV-2 and was most pronounced in the least symptomatic individuals.

Both asymptomatic and mild individuals showed increased SARS-CoV-2 peplomer-specific IgM, IgA, IgG1, and IgG3 responses.

Interestingly, one symptomatic or asymptomatic individual develops only S2-specific Fc receptor-binding antibodies and evolves other Fc receptor-binding antibodies specific for other SARS-CoV-2 moieties. did not.

*Important Notices

bioRxiv Publish preliminary scientific reports that should not be considered definitive as they are not peer-reviewed, guide clinical practice / health-related behaviors, and should not be treated as established information.