Project description:In June 2009, the World Health Organization declared the first influenza pandemic of the 21st century, due to the emergence and rapid spread of new swine origin H1N1 influenza A virus. In contrast to seasonal influenza infections, which typically cause morbidity and mortality in the elderly, this virus caused severe infection in young adults and not the elderly. This phenomenon was attributed to the presence of cross-neutralizing antibodies acquired by older individuals from previous exposure to swine origin influenza. However, this hypothesis could not be empirically tested using clinical data. To address this question, we investigated viral replication and the development of the immune response in naï12 years old) and aged (20 to 24 years old) female rhesus macaques infected with A/California/04/2009 (H1N1), one of the circulating pandemic strains in 2009. We compared viral loads as well as the kinetics and magnitude of the adaptive immune response in peripheral blood and bronchoalveolar lavage samples (BAL) collected longitudinally for 99 days post-infection. Although, adult animals exhibited earlier T cell responses in peripheral blood, aged animals generated a robust T cell response with comparable kinetics and magnitude as those observed in young animals in BAL. Moreover, aged animals generated a higher hemagglutination inhibition titer compared to young animals. We also measured the concentration of several cytokines in BAL supernatant. With the exception of IL-8, which was higher in aged animals, we found no differences in IFNa, IFNb, TNFa, IL-1r, IL-6, IL-15, IL-17, or MCP1 levels. Finally, we compared gene expression infection using microarray analysis of BAL samples taken on days 0, 4, 7, 10, and 14 pi. Our analyses revealed that the largest difference in host response between aged and young animals was detected day 4 post-infection, with significant enrichment for genes associated with inflammation, the innate immune response, and T cell activation in aged animals. The ability of aged animals to generate a robust immune response, especially antibody response, following infection with 2009 H1N1 virus could explain the lack of morbidity normally observed with seasonal influenza viruses in this vulnerable population.

Project description:In June 2009, the World Health Organization declared the first influenza pandemic of the 21st century, due to the emergence and rapid spread of new swine origin H1N1 influenza A virus. In contrast to seasonal influenza infections, which typically cause morbidity and mortality in the elderly, this virus caused severe infection in young adults and not the elderly. This phenomenon was attributed to the presence of cross-neutralizing antibodies acquired by older individuals from previous exposure to swine origin influenza. However, this hypothesis could not be empirically tested using clinical data. To address this question, we investigated viral replication and the development of the immune response in naï12 years old) and aged (20 to 24 years old) female rhesus macaques infected with A/California/04/2009 (H1N1), one of the circulating pandemic strains in 2009. We compared viral loads as well as the kinetics and magnitude of the adaptive immune response in peripheral blood and bronchoalveolar lavage samples (BAL) collected longitudinally for 99 days post-infection. Although, adult animals exhibited earlier T cell responses in peripheral blood, aged animals generated a robust T cell response with comparable kinetics and magnitude as those observed in young animals in BAL. Moreover, aged animals generated a higher hemagglutination inhibition titer compared to young animals. We also measured the concentration of several cytokines in BAL supernatant. With the exception of IL-8, which was higher in aged animals, we found no differences in IFNa, IFNb, TNFa, IL-1r, IL-6, IL-15, IL-17, or MCP1 levels. Finally, we compared gene expression infection using microarray analysis of BAL samples taken on days 0, 4, 7, 10, and 14 pi. Our analyses revealed that the largest difference in host response between aged and young animals was detected day 4 post-infection, with significant enrichment for genes associated with inflammation, the innate immune response, and T cell activation in aged animals. The ability of aged animals to generate a robust immune response, especially antibody response, following infection with 2009 H1N1 virus could explain the lack of morbidity normally observed with seasonal influenza viruses in this vulnerable population. 16 female rhesus macaques (Macaca Mulatta) 10-12 (Adult) and 20-24 years (Old/Aged) of age were used in these studies. Animals were infected with A/California/04/ 2009 H1N1 using a combinatory of intra-tracheal (4ml), intranasal (0.5 ml/nostril), and conjunctival (0.5 ml/eyelid) routes for a total dose of 7x106 TCID50 dose. Microarray analysis was performed on Bronchoalveolar lavage (BAL) samples collected on days 0, 4, 7, 10 and 14. Note: One of the Day 0 array did not pass QC metrics so for this animal the average of the other Day 0 samples from that group was utilized. At the end of the study animals were released back to the colony.

Project description:ImportanceData are limited on whether patients with breakthrough COVID-19 infection have the potential to significantly contribute to the spread of SARS-CoV-2.ObjectiveTo compare the secondary attack rate and infectious viral shedding kinetics of SARS-CoV-2 between fully vaccinated individuals (breakthrough infection group) and partially or unvaccinated individuals (nonbreakthrough infection group).Design, setting, and participantsThis cohort study assessed secondary transmission by analyzing the epidemiologic data of health care workers, inpatients, and caregivers diagnosed with COVID-19 during hospitalization or residence in a tertiary care hospital between March 1, 2020, and November 6, 2021. To evaluate viral shedding kinetics, the genomic RNA of SARS-CoV-2 was measured using polymerase chain reaction and performed virus culture from daily saliva samples of individuals with mild COVID-19 infected with the Delta variant who were isolated in a community facility in Seoul, South Korea, between July 20 and August 20, 2021.ExposuresCOVID-19 vaccination.Main outcomes and measuresThe secondary attack rate and infectious viral shedding kinetics according to COVID-19 vaccination status.ResultsA total of 173 individuals (median [IQR] age, 47 [32-59] years; 100 female [58%]) with COVID-19 were included in the secondary transmission study, of whom 50 (29%) had a breakthrough infection. Secondary transmission was significantly less common in the breakthrough infection group than in the nonbreakthrough infection group (3 of 43 [7%] vs 29 of 110 [26%]; P = .008). In the viral shedding kinetics study, 45 patients (median age, 37 years [IQR, 25-49 years]; 14 female [31%]) infected with the Delta variant were included, of whom 6 (13%) were fully vaccinated and 39 (87%) were partially or unvaccinated. Although the initial genomic viral load was comparable between the 2 groups, viable virus in cell culture was detected for a notably longer duration in partially vaccinated (8 days after symptom onset) or unvaccinated (10 days after symptom onset) individuals compared with fully vaccinated individuals (4 days after symptom onset).Conclusions and relevanceIn this cohort study, although the initial genomic viral load was similar between vaccinated and unvaccinated individuals, fully vaccinated individuals had a shorter duration of viable viral shedding and a lower secondary attack rate than partially vaccinated or unvaccinated individuals. Data from this study provide important evidence that despite the possibility of breakthrough infections, COVID-19 vaccinations remain critically useful for controlling the spread of SARS-CoV-2.

Project description:Antibodies play an important part in combating SARS‐CoV‐2 infection whether generated by the infection or vaccination. However, the many epitopes generated by infection have not been fully investigated with only a few epitopes known and these being mostly limited to the S protein’s receptor binding domain (RBD) and the N‐terminal domain which limits vaccine and drug design 1‐4. The difference between epitopes generated by infection and vaccination has also not been studied. To address this, we employed a SARS‐CoV‐2 proteome microarray to screen for linear epitopes recognized by antibodies present in COVID‐19 patients and individuals vaccinated with the Pfizer‐BioNTech mRNA COVID‐19 Vaccine. The proteome microarray consisted of S, N, and E proteins, as well as spotting peptides that were 15 amino acids in length with overlaps of 5‐amino acids, covering the entire SARS‐CoV‐2 proteome (MN908947.3) (Figure 1). Blood samples were incubated onto the arrays followed by an incubation of fluorescent secondary anti‐human antibodies. Fluorescent intensity data generated and normalized using the Z‐score method and then further analyzed for significance by parametric one‐way ANOVA with Dunnett's post hoc test (COVID‐19 cohort) and repeated measure ANOVAs with Dunnett's post hoc tests (vaccinated cohort). The full‐length S protein showed a significant increase in COVID‐19 patients at around 20‐23 days after symptom onset and vaccinated individuals over all time points in both IgM and IgG antibodies (Figure 2A). Linear mapping of the IgM epitopes revealed a degree of overlap between infected and vaccinated individuals (22.2%; 6/27 total) with both having epitopes in the RBD and fusion peptide (FP) (Figure 2B). Structural mapping on 3D models of the S protein showed that all epitopes where on the surface of the protein and that COVID‐19 generated epitopes have a different pattern than those generated by vaccination (Figure 2C). An Epitope identified in this study with future prospects is epitope S481‐495 from COIVD‐19 patients that partially overlapped the binding site of two neutralizing antibodies previously isolated from COVID‐19 patients, S2H135 and F2B‐2F61, and contacted amino acids that interact with ACE2 receptor6,7. One epitope of note from the vaccinated individuals is epitope S811‐825 which mapped adjacent to the fusion‐peptide proximal region. These epitopes may be helpful in future vaccine and antibody therapy development. 1 Ju, B. et al. Nature 584, 115‐119. 2 Robbiani, D. F. et al. Nature 584, 437‐442. 3 Seydoux, E. et al. bioRxiv. 4 Wu, Y. et al. Science 368, 1274‐1278. 5 Piccoli, L. et al. Cell 183, 1024‐1042 e1021. 6 Casalino, L. et al. ACS Cent Sci 6, 1722‐1734. 7 Wang, Q. et al. Cell 181, 894‐904 e899.

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Difference in immune response in vaccinated and unvaccinated Swedish individuals after the 2009 influenza pandemic.

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Difference in immune response in vaccinated and unvaccinated Swedish individuals after the 2009 influenza pandemic.

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