Ma MJ, et al. Characterization of antibody and memory T cell response in H7N9 survivors: A cross-sectional analysis. Clin Microbiol Infect. 2019 Jun 20
Despite the importance of immunological memory for protective immunity against viral infection, whether H7N9-specific antibodies and memory T-cell responses remain detectable years after the original infection is unknown.
A cross-sectional study was conducted to investigate the immune memory responses of H7N9 patients who contracted the disease and survived during the 2013-2016 epidemics in China. Sustainability of antibodies and T-cell memory to H7N9 virus were examined. Healthy subjects receiving routine medical examination in physical examination center were recruited as control.
A total of 75 survivors were enrolled and classified into four groups based on the time elapsed from illness onset to specimen collection: three months (n=14), 14 months (n=14), 26 months (n=28), and 36 months (n=19). Approximately 36 months after infection, the geometric mean titers of virus-specific antibodies were significantly lower than titers in patients of three months after infection, but 16 of 19 (84.2%) survivors in the 36-month interval had microneutralization (MN) titer > 40. Despite the overall declining trend, the percentages of virus-specific cytokines-secreting memory CD4+ and CD8+ T-cells remained higher in survivors at nearly all time points in comparison with control subjects. Linear regression analysis showed that severe disease (mean titer ratio 2.77, 95%CI 1.17-6.49) was associated with higher hemagglutination inhibition (HI) titer, and female sex for both HI (1.92, 1.02-3.57) and MN (3.33, 1.26-9.09) antibody, whereas female sex (mean percentage ratio 1.69, 95%CI 1.08-2.63), underlying medical conditions (1.94, 95%CI 1.09-3.46), and lack of antiviral therapy (2.08, 95%CI 1.04-4.17) were predictors for higher T-cell responses.
Survivors from H7N9 virus infection produced long-term antibodies and memory T-cells responses. Our findings warrant further serological investigation in general and high-risk populations and have important implications for vaccine design and development.
- A Homeostasis Hypothesis of Avian Influenza Resistance in Chickens 1 days ago
- The Val430Ile neuraminidase (NA) substitution, identified in influenza B virus isolates, impacts the catalytic 116Arg residue causing reduced susceptibility to NA inhibitors 1 days ago
- New antibody-based prevention and treatment options for influenza 1 days ago
- Interventions in live poultry markets for the control of avian influenza: A systematic review and meta-analysis 1 days ago
- Continuous evolution of influenza A viruses of swine from 2013 to 2015 in Guangdong, China 1 days ago