Specificity, kinetics and longevity of antibody responses to avian influenza A(H7N9) virus infection in humans

Abstract

s u m m a r yObjectives: The long-term dynamics of antibody responses in patients with influenza A(H7N9) virus infection are not well understood. Methods: We conducted a longitudinal serological follow-up study in patients who were hospitalized with A(H7N9) virus infection, during 2013-2018. A(H7N9) virus-specific antibody responses were assessed by hemagglutination inhibition (HAI) and neutralization (NT) assays. A random intercept model was used to fit a curve to HAI antibody responses over time. HAI antibody responses were compared by clinical severity. Results: Of 67 patients with A(H7N9) virus infection, HAI antibody titers reached 40 on average 11 days after illness onset and peaked at a titer of 290 after three months, and average titers of ≥80 and ≥40 were present until 11 months and 22 months respectively. HAI antibody responses were significantly higher in patients who experienced severe disease, including respiratory failure and acute respiratory distress syndrome, compared with patients who experienced less severe illness. Conclusions: Patients with A(H7N9) virus infection who survived severe disease mounted higher antibody responses that persisted for longer periods compared with those that experienced moderate disease. Studies of convalescent plasma treatment for A(H7N9) patients should consider collection of donor plasma from survivors of severe disease between 1 and 11 months after illness onset.

Treatment With Convalescent Plasma for Critically Ill Patients With Severe Acute Respiratory Syndrome Coronavirus 2 Infection

“…Patients who survive critical illness might mount higher antibody responses, which can persist for longer periods compared with those with nonsevere disease. 14 The antibody levels, however, are confounded by other treatments, such as antiviral drugs, steroids, and IV immunoglobulin. 15 A recent animal model indicated that antibodies produced from SARS-CoV-2 infection could protect from subsequent exposures.…”

Anti-SARS-CoV-2 virus antibody levels in convalescent plasma of six donors who have recovered from COVID-19

“…The weakness of the study should be noted that the clinical relevance of antibody titers in protecting against subsequent SARS-CoV-2 infection is uncertain. Compared to ELISAs, neutralization assays require virus culture, are much more labor-intensive, and need to be conducted in laboratories with higher biosafety levels [15,16]. We are currently conducting neutralization studies to further investigate whether ELISA results were correlated with neutralization results so far as to substitute for the neutralization test in resource-limited situations.…”

Analysis of the WHO ICTRP for novel coronavirus clinical trial registrations

“…Convalescent plasma therapy (CPT) is passive immunotherapy that works to neutralize the antibodies against pathogens and is obtained from the plasma of recovery patients. This treatment strategy has been used in the treatment of outbreaks of infectious diseases such as influenza, [ 24 ] measles, hemorrhagic fever in Argentina, Zika virus infection, [ 25 ] MERS, [ 26 ] and SARS. Research on plasma replacement antibodies containing highly potent anti-SARS-CoV-2, donated by recovered patients, has shown promising results, and these neutralizing antibodies have been used in the treatment of critically ill COVID-19 patients.…”