Advance warning of pathogen outbreaks has not been possible heretofore. A new class of genomic peptides associated with rapid replication was discovered and named replikins. Software was designed to analyze replikins quantitatively. Replikin concentration changes were measured annually prior to, and “real time” every few days during, the 2009 H1N1 influenza pandemic. Replikins were seen by both linear sequence representation and three-dimensional X-ray diffraction, and found to expand on the virus hemagglutinin surface prior to and during the H1N1 pandemic.A highly significant increased concentration of virus replikins was found a) retrospectively in three pandemics from 1918 to 1999 (14,227 sequences)(p<0.001), and b) prospectively before the H1N1 2009 pandemic (12,806 sequences) (in the hemagglutinin gene (N=8,046), p values by t-test = 1/10130, by linear regression = 1/1024 and 1/1029, by Spearman correlation < 2/1016, by Wilcoxon rank sum<1/1016, by multiple regression adjusting for correlation between consecutive years = 2/1022. Rising replikin concentration in H1N1 from 2006 to 2008, predicted one year in advance the H1N1 outbreak of 2009; and in H5N1, predicted the lethal outbreaks of H5N1 1997-2010.The possible combination of influenza strains H1N1 (high infectivity) and H5N1 (high lethality) is a matter of global concern (1,2). The risk of a combined H1N1 (high infectivity) - H5N1 (high lethality) outbreak may have increased because first, the Replikin Counts of the two virus strains have risen simultaneously, not seen previously; second, the rise is to the highest levels recorded since 1918 for H1N1, in Mexico (16.7), and since 1957 for H5N1, in Egypt (23.3); and third, clinical outbreaks of each strain are occurring in 2011. These simultaneous conditions may increase the risk that the two virus strains might come into contact with each other more frequently, facilitating transfer of genomic material to form a hybrid.
In this study, the sequence of the H5 and PB1 genes of the low-pathogenic avian influenza virus (LPAI) A/Black Duck/NC/674-964/06 isolate were determined for replikin peptides and used to design and chemically synthesize a vaccine. The vaccine was used to immunize specific-pathogen-free (SPF) leghorn chickens held in Horsfall isolation units, by the upper respiratory route, at 1, 7, and 14 days of age. The birds were challenged at 28 days of age with 1 x 10(6) 50% embryo infective dose of the LPAI Black Duck/NC/674-964/06 H5N1 virus per bird. Oropharyngeal and cloacal swabs were collected at 2, 4, and 7 days postinoculation (PI) for virus detection by real-time RT-PCR. Serum was collected at 7, 14, and 21 days PI and examined for antibodies against avian influenza virus by the enzyme-linked immunosorbent assay and hemagglutination inhibition (HI) tests. Tissue samples for histopathology were collected from three birds per group at 3 days PI. The experimental design consisted of a negative control group (not vaccinated and not challenged) and a vaccinated group, a vaccinated and challenged group, and a positive control group (challenged only). None of the nonchallenged birds, the vaccinated birds, or the vaccinated and challenged birds showed overt clinical signs of disease during the study. A slight depression was observed in the nonvaccinated challenged birds on day 2 postchallenge. Although the numbers of birds per group are small, no shedding of the challenge virus was detected in the vaccinated and challenged birds, whereas oropharyngeal and cloacal shedding was detected in the nonvaccinated and challenged birds. HI antibodies were detected in the vaccinated and nonchallenged group as well as in the vaccinated and challenged group, but rising antibody titers, indicating infection with the LPAI challenge virus, were not detected. Rising HI titers were observed in the nonvaccinated and challenged group. In addition, no antibodies were detected in the nonchallenged birds. Noteworthy microscopic lesions were not observed in the vaccinated and challenged birds, whereas nonvaccinated-challenged birds had microscopic lesions consistent with infection with LPAI viruses. Taken together, these data indicate that a replikin peptide vaccine, specifically made against the H5N1 Black Duck/NC/674-964/06 isolate, and administered three times to the upper respiratory tract, was capable of protecting chickens from infection and from shedding of the homologous virus, which is extremely important because reduced virus shedding and transmission decreases the potential for H5 LPAI viruses to become HPAI viruses. The study is also important because it shows that the vaccine can be effectively mass-delivered to the upper respiratory tract.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
customersupport@researchsolutions.com
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.