A few studies have assessed immunologic changes during and after a COVID-19 infection. Some results have suggested that neutralising antibodies are protective. At the ERS 2020 Congress, Prof. Peter Openshaw (Imperial College of London, UK) reviewed some immunological considerations from recent COVID-19 studies .
“What we know about this virus is just changing from hour to hour,” said Prof. Openshaw. A few initial studies from China have shown a neutralising antibody response to SARS-CoV-2 in a patient cohort that recovered from COVID-19 . The results suggest that there is more antibody production in patients with severe disease. Unfortunately, asymptomatic individuals have a weaker immune response to SARS-CoV-2 infection, as shown by a Chinese study in 37 asymptomatic individuals . This study assessed the clinical features and immune responses of asymptomatic patients with a SARS-CoV-2 infection and found that 81.1% of the 37 asymptomatic participants showed declining neutralising antibodies in the convalescent phase, compared with 62.2% of symptomatic participants. 40% of asymptomatic individuals became seronegative compared with 12.9% of the symptomatic group. Interestingly, duration of viral shedding was longer in asymptomatic individuals compared with those with symptoms. Moreover, asymptomatic individuals exhibited lower level of 18 pro-inflammatory and anti-inflammatory cytokines.
In the United Kingdom, the ISARIC-4C (Coronavirus Clinical Characterisation Consortium) cohort collected data from COVID-19 patients. Up to July 2020, demographic data, outcomes, and comorbidities of 64,323 patients were collected (Tier 0). Single biological samples from plasma/serum, nasal swabs, urine, and stools were collected from 644 patients. Serial biological sample sets are available from another 1,625 patients. One of the first studies that came from this cohort assessed the T-cell response during infection with COVID-19 in 28 patients with mild disease and 14 with severe disease . This study showed that memory T-cell responses were greater in severe cases.
In a North America cohort, a study on the humoral immune response to SARS-CoV-2 showed that IgG, IgA, and IgM antibody responses were accurate in identifying recently infected individuals, with 100% specificity and 97%, 91%, and 81% sensitivity, respectively . IgA and IgM antibodies were short-lived. IgG antibodies lasted longer and persisted through 75 days post-symptoms. The authors concluded that IgG antibodies are correlated with neutralising antibodies and are possibly a correlate of protective immunity. A study on the outbreak of SARS-CoV-2 on a fishing vessel further showed that the presence of high neutralising antibodies was associated with protection (P=0.002) . “This finding is important because it tells us that the presence of antibodies is protective,” Prof. Openshaw said.
Taken together, these results show that a COVID-19 infection primes B and T cell immunity. “It is not clear whether the protection by viral infection stays more than a few months, but vaccines may possibly induce better immunity than natural infection,” Prof. Openshaw concluded.
- Openshaw P. Immunology underpinning vaccine strategy: what is the risk of reinfection? COV3619, ERS International Virtual Congress 2020, 7-9 Sept.
- Wu F, et al. Preprint at medRxiv.Doi:10.1101/2020.03.30.20047365.
- Long QX, et al. Nat Med 2020 Aug;26(8):1200-1204.
- Peng Y, et al. Nat Immunol. DOI:10.1038/s41590-020-0782-6.
- Iyer AS, et al. Preprint at medRxiv. Doi:10.1101/2020.07.18.20155374.
- Addetia A, et al. J Clin Microbiol 2020.Doi:10.1128/JCM.02107-20.
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COVID-19 vaccines: An ongoing race »
Table of Contents: ERS 2020
Letter from the Editor
ERS 2020 Highlights Podcast
COVID-19 and the Lung
COVID-19 infections: Bronchoscopy provides additional diagnostic certainty
COVID-19 vaccines: An ongoing race
COVID-19: What is the risk of reinfection?
COVID-19 App: The Dutch experience
Secondary pulmonary fibrosis: a possible long-term effect of severe COVID-19
COVID-19 survivors benefit from structured follow-up
Early pulmonary rehabilitation post-COVID-19 aids recovery
Asthma – What's New
Mild asthma: A fundamental change in management
Dupilumab shows long-term efficacy in asthma patients
Severe asthma: Oral corticosteroids maintenance therapy associated with toxicity
First-in-class tyrosine kinase inhibitor shows promise in severe asthma
Predicting individual effectiveness of biologics in severe asthma
IL-5 antagonist showed efficacy in chronic rhinosinusitis with nasal polyps
Treatment according to genotype: The future of asthma therapy?
COPD – The Beat Goes On
The role of chronic symptoms as early biomarkers of COPD development
Urgent call for studies in COPD patients aged 40-60 years
Nasal high-flow therapy: a novel treatment option for hypercapnic COPD patients
Exacerbation history is a reliable predictor of future exacerbations
Singing training effective as physical rehabilitation in COPD
Current prediction tools underestimate exacerbation risk of severe COPD patients
Exercise and Sleep: From Impaired Function to New Therapeutic Strategies
CPAP withdrawal has negative consequences for sleep apnoea patients
Physical activity improves AHI in sleep apnoea patients
The Tobacco Epidemic: From Vaping to Cannabis
Poly-use of nicotine products and cannabis: a deadly combination
E-cigarettes: A source of chronic lung inflammation
Social smoking: Do not underestimate the risks
Chronic Cough – State of the Art
LEAD study shows multiple phenotypes in many chronic cough patients
First-in-class P2X3 receptor antagonist shows promise for chronic cough treatment
Lung Cancer Detection
Lung cancer screening: Most patients not eligible 1-2 years prior to diagnosis
Biomarkers: a novel tool to improve lung nodule classification
Distinct changes in lung microbiome precede clinical diagnosis of lung cancer
Best of Posters
Smartphone-based cough detection helpful in predicting asthma deterioration
Reduced lung function associated with cognitive decline in the elderly
Longer hospital stay and fewer transplants for frail ILD patients
Mild asthma: A fundamental change in management
Impact of COVID-19 on the dynamics of respiratory viruses
Novel P2X3 antagonist can SOOTHE chronic cough