| 1. |
- Wallensten, Anders, et al.
(författare)
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Surveillance of influenza A virus in migratory waterfowl in northern Europe
- 2007
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Ingår i: Emerging Infectious Diseases. - 1080-6040 .- 1080-6059. - 1080-6040 ; 13:3, s. 404-411
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Tidskriftsartikel (refereegranskat)abstract
- We conducted large-scale, systematic sampling of influenza type A virus in migratory waterfowl (mostly mallards [Anas platyrhynchos]) at Ottenby Bird Observatory, southeast Sweden. As with previous studies, we found a higher prevalence in fall than spring, and among juveniles compared with adults. However, in contrast to other studies, we found that prevalence in spring was sometimes high (mean 4.0%, highest 9.5%). This finding raises the possibility that ducks are capable of perpetuating influenza A virus of different subtypes and subtype combinations throughout the year and from 1 year to the next. Isolation of the H5 and H7 subtypes was common, which suggests risk for transmission to sensitive domestic animals such as poultry. We argue that wild bird screening can function as a sentinel system, and we give an example of how it could have been used to forecast a remote and deadly outbreak of influenza A in poultry.
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| 2. |
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| 3. |
- de Sandt, Carolien E. van, et al.
(författare)
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Novel G3/DT adjuvant promotes the induction of protective T cells responses after vaccination with a seasonal trivalent inactivated split-virion influenza vaccine
- 2014
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Ingår i: Vaccine. - : Elsevier BV. - 0264-410X .- 1873-2518. ; 32:43, s. 5614-5623
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Tidskriftsartikel (refereegranskat)abstract
- Vaccines used against seasonal influenza are poorly effective against influenza A viruses of novel subtypes that may have pandemic potential. Furthermore, pre(pandemic) influenza vaccines are poorly immunogenic, which can be overcome by the use of adjuvants. A limited number of adjuvants has been approved for use in humans, however there is a need for alternative safe and effective adjuvants that can enhance the immunogenicity of influenza vaccines and that promote the induction of broad-protective T cell responses. Here we evaluated a novel nanoparticle, G3, as an adjuvant for a seasonal trivalent inactivated influenza vaccine in a mouse model. The G3 adjuvant was formulated with or without steviol glycosides (DT, for diterpenoid). The use of both formulations enhanced the virus-specific antibody response to all three vaccine strains considerably. The adjuvants were well tolerated without any signs of discomfort. To assess the protective potential of the vaccine-induced immune responses, an antigenically distinct influenza virus strain, A/Puerto Rico/8/34 (A/PR/8/34), was used for challenge infection. The vaccine-induced antibodies did not cross-react with strain A/PR/8/34 in HI and VN assays. However, mice immunized with the G3/DT-adjuvanted vaccine were partially protected against A/PR/8/34 infection, which correlated with the induction of anamnestic virus-specific CD8(+) T cell responses that were not observed with the use of G3 without DT. Both formulations induced maturation of human dendritic cells and promoted antigen presentation to a similar extent. In conclusion, G3/DT is a promising adjuvant formulation that not only potentiates the antibody response induced by influenza vaccines, but also induces T cell immunity which could afford broader protection against antigenically distinct influenza viruses.
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| 4. |
- van Boheemen, Sander, et al.
(författare)
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A family-wide RT-PCR assay for detection of paramyxoviruses and application to a large-scale surveillance study.
- 2012
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Ingår i: PLOS ONE. - : Public Library of Science (PLoS). - 1932-6203. ; 7:4
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Tidskriftsartikel (refereegranskat)abstract
- Family-wide molecular diagnostic assays are valuable tools for initial identification of viruses during outbreaks and to limit costs of surveillance studies. Recent discoveries of paramyxoviruses have called for such assay that is able to detect all known and unknown paramyxoviruses in one round of PCR amplification. We have developed a RT-PCR assay consisting of a single degenerate primer set, able to detect all members of the Paramyxoviridae family including all virus genera within the subfamilies Paramyxovirinae and Pneumovirinae. Primers anneal to domain III of the polymerase gene, with the 3' end of the reverse primer annealing to the conserved motif GDNQ, which is proposed to be the active site for nucleotide polymerization. The assay was fully optimized and was shown to indeed detect all available paramyxoviruses tested. Clinical specimens from hospitalized patients that tested positive for known paramyxoviruses in conventional assays were also detected with the novel family-wide test. A high-throughput fluorescence-based RT-PCR version of the assay was developed for screening large numbers of specimens. A large number of samples collected from wild birds was tested, resulting in the detection of avian paramyxoviruses type 1 in both barnacle and white-fronted geese, and type 8 in barnacle geese. Avian metapneumovirus type C was found for the first time in Europe in mallards, greylag geese and common gulls. The single round family-wide RT-PCR assay described here is a useful tool for the detection of known and unknown paramyxoviruses, and screening of large sample collections from humans and animals.
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| 5. |
- Fouchier, Ron A M, et al.
(författare)
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Characterization of a novel influenza A virus hemagglutinin subtype (H16) obtained from black-headed gulls.
- 2005
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Ingår i: J Virol. - : ASM International. - 0022-538X .- 1098-5514. ; 79:5, s. 2814-22
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Tidskriftsartikel (refereegranskat)abstract
- In wild aquatic birds and poultry around the world, influenza A viruses carrying 15 antigenic subtypes of hemagglutinin (HA) and 9 antigenic subtypes of neuraminidase (NA) have been described. Here we describe a previously unidentified antigenic subtype of HA (H16), detected in viruses circulating in black-headed gulls in Sweden. In agreement with established criteria for the definition of antigenic subtypes, hemagglutination inhibition assays and immunodiffusion assays failed to detect specific reactivity between H16 and the previously described subtypes H1 to H15. Genetically, H16 HA was found to be distantly related to H13 HA, a subtype also detected exclusively in shorebirds, and the amino acid composition of the putative receptor-binding site of H13 and H16 HAs was found to be distinct from that in HA subtypes circulating in ducks and geese. The H16 viruses contained NA genes that were similar to those of other Eurasian shorebirds but genetically distinct from N3 genes detected in other birds and geographical locations. The European gull viruses were further distinguishable from other influenza A viruses based on their PB2, NP, and NS genes. Gaining information on the full spectrum of avian influenza A viruses and creating reagents for their detection and identification will remain an important task for influenza surveillance, outbreak control, and animal and public health. We propose that sequence analyses of HA and NA genes of influenza A viruses be used for the rapid identification of existing and novel HA and NA subtypes.
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| 6. |
- Munster, Vincent J., et al.
(författare)
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Spatial, temporal, and species variation in prevalence of influenza A viruses in wild migratory birds
- 2007
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Ingår i: PLoS Pathogens. - : Public Library of Science (PLoS). - 1553-7366 .- 1553-7374. ; 3:5, s. 630-638
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Tidskriftsartikel (refereegranskat)abstract
- Although extensive data exist on avian influenza in wild birds in North America, limited information is available from elsewhere, including Europe. Here, molecular diagnostic tools were employed for high-throughput surveillance of migratory birds, as an alternative to classical labor-intensive methods of virus isolation in eggs. This study included 36,809 samples from 323 bird species belonging to 18 orders, of which only 25 species of three orders were positive for influenza A virus. Information on species, locations, and timing is provided for all samples tested. Seven previously unknown host species for avian influenza virus were identified: barnacle goose, bean goose, brent goose, pink-footed goose, bewick's swan, common gull, and guillemot. Dabbling ducks were more frequently infected than other ducks and Anseriformes; this distinction was probably related to bird behavior rather than population sizes. Waders did not appear to play a role in the epidemiology of avian influenza in Europe, in contrast to the Americas. The high virus prevalence in ducks in Europe in spring as compared with North America could explain the differences in virus–host ecology between these continents. Most influenza A virus subtypes were detected in ducks, but H13 and H16 subtypes were detected primarily in gulls. Viruses of subtype H6 were more promiscuous in host range than other subtypes. Temporal and spatial variation in influenza virus prevalence in wild birds was observed, with influenza A virus prevalence varying by sampling location; this is probably related to migration patterns from northeast to southwest and a higher prevalence farther north along the flyways. We discuss the ecology and epidemiology of avian influenza A virus in wild birds in relation to host ecology and compare our results with published studies. These data are useful for designing new surveillance programs and are particularly relevant due to increased interest in avian influenza in wild birds.
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| 7. |
- Latorre-Margalef, Neus, et al.
(författare)
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Heterosubtypic Immunity to Influenza A Virus Infections in Mallards May Explain Existence of Multiple Virus Subtypes
- 2013
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Ingår i: PLoS Pathogens. - : Public Library of Science (PLoS). - 1553-7366 .- 1553-7374. ; 9:6, s. e1003443-
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Tidskriftsartikel (refereegranskat)abstract
- Wild birds, particularly duck species, are the main reservoir of influenza A virus (IAV) in nature. However, knowledge of IAV infection dynamics in the wild bird reservoir, and the development of immune responses, are essentially absent. Importantly, a detailed understanding of how subtype diversity is generated and maintained is lacking. To address this, 18,679 samples from 7728 Mallard ducks captured between 2002 and 2009 at a single stopover site in Sweden were screened for IAV infections, and the resulting 1081 virus isolates were analyzed for patterns of immunity. We found support for development of homosubtypic hemagglutinin (HA) immunity during the peak of IAV infections in the fall. Moreover, re-infections with the same HA subtype and related prevalent HA subtypes were uncommon, suggesting the development of natural homosubtypic and heterosubtypic immunity (p-value = 0.02). Heterosubtypic immunity followed phylogenetic relatedness of HA subtypes, both at the level of HA clades (p-value = 0.04) and the level of HA groups (p-value = 0.05). In contrast, infection patterns did not support specific immunity for neuraminidase (NA) subtypes. For the H1 and H3 Clades, heterosubtypic immunity showed a clear temporal pattern and we estimated within-clade immunity to last at least 30 days. The strength and duration of heterosubtypic immunity has important implications for transmission dynamics of IAV in the natural reservoir, where immune escape and disruptive selection may increase HA antigenic variation and explain IAV subtype diversity.
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| 8. |
- Latorre-Margalef, Neus, et al.
(författare)
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Long-term variation in influenza A virus prevalence and subtype diversity in migratory mallards in northern Europe.
- 2014
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Ingår i: Proceedings of the Royal Society of London. Biological Sciences. - : The Royal Society. - 0962-8452 .- 1471-2954. ; 281:1781, s. 20140098-
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Tidskriftsartikel (refereegranskat)abstract
- Data on long-term circulation of pathogens in wildlife populations are seldom collected, and hence understanding of spatial-temporal variation in prevalence and genotypes is limited. Here, we analysed a long-term surveillance series on influenza A virus (IAV) in mallards collected at an important migratory stopover site from 2002 to 2010, and characterized seasonal dynamics in virus prevalence and subtype diversity. Prevalence dynamics were influenced by year, but retained a common pattern for all years whereby prevalence was low in spring and summer, but increased in early autumn with a first peak in August, and a second more pronounced peak during October-November. A total of 74 haemagglutinin (HA)/neuraminidase (NA) combinations were isolated, including all NA and most HA (H1-H12) subtypes. The most common subtype combinations were H4N6, H1N1, H2N3, H5N2, H6N2 and H11N9, and showed a clear linkage between specific HA and NA subtypes. Furthermore, there was a temporal structuring of subtypes within seasons based on HA phylogenetic relatedness. Dissimilar HA subtypes tended to have different temporal occurrence within seasons, where the subtypes that dominated in early autumn were rare in late autumn, and vice versa. This suggests that build-up of herd immunity affected IAV dynamics in this system.
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| 9. |
- Munster, Vincent J, et al.
(författare)
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Mallards and highly pathogenic avian influenza ancestral viruses, northern Europe
- 2005
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Ingår i: Emerging Infectious Diseases. - Atlanta : Center of disease control. - 1080-6040 .- 1080-6059. ; 11:10, s. 1545-1551
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Tidskriftsartikel (refereegranskat)abstract
- Outbreaks of highly pathogenic avian influenza (HPAI), which originate in poultry upon transmission of low pathogenic viruses from wild birds, have occurred relatively frequently in the last decade. During our ongoing surveillance studies in wild birds, we isolated several influenza A viruses of hemagglutinin subtype H5 and H7 that contain various neuraminidase subtypes. For each of the recorded H5 and H7 HPAI outbreaks in Europe since 1997, our collection contained closely related virus isolates recovered from wild birds, as determined by sequencing and phylogenetic analyses of the hemagglutinin gene and antigenic characterization of the hemagglutinin glycoprotein. The minor genetic and antigenic diversity between the viruses recovered from wild birds and those causing HPAI outbreaks indicates that influenza A virus surveillance studies in wild birds can help generate prototypic vaccine candidates and design and evaluate diagnostic tests, before outbreaks occur in animals and humans.
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| 10. |
- Munster, Vincent J, et al.
(författare)
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Towards improved influenza A virus surveillance in migrating birds.
- 2006
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Ingår i: Vaccine. - : Elsevier BV. - 0264-410X .- 1873-2518. ; 24:44-46, s. 6729-33
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Tidskriftsartikel (refereegranskat)abstract
- The last decade has seen a marked increase in highly pathogenic avian influenza (HPAI) outbreaks around the world. This increase and the zoonotic potential of some of the HPAI viruses are of great concern to animal and public health as well as biodiversity. It is now well recognized that global influenza virus surveillance in wild birds can play a key role in the early recognition of and preparation for these threats. Here we summarize the most important results from our wild bird surveillance studies in Northern Europe over the last 8 years and conclude that surveillance studies in wild birds are indeed useful to generate prototypic vaccine candidates and to design and evaluate diagnostic tests, prior to the occurrence of outbreaks in animals and humans. Through this 8-year experience we also identified gaps in our knowledge on influenza A viruses and their natural hosts which may help to assist in the design of improved surveillance studies. This is particularly relevant if wild bird surveillance studies are used as an "early warning system" for the arrival of the H5N1 HPAI virus in a country or region and to assess the risk posed by these viruses in general.
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| 11. |
- Olsen, Björn, et al.
(författare)
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Global patterns of influenza A virus in wild birds
- 2006
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Ingår i: Science. - : American Association for the Advancement of Science (AAAS). - 0036-8075 .- 1095-9203. ; 312:5772, s. 384-388
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Tidskriftsartikel (refereegranskat)abstract
- The outbreak of highly pathogenic avian influenza of the H5N1 subtype in Asia, which has subsequently spread to Russia, the Middle East, Europe, and Africa, has put increased focus on the role of wild birds in the persistence of influenza viruses. The ecology, epidemiology, genetics, and evolution of pathogens cannot be fully understood without taking into account the ecology of their hosts. Here, we review our current knowledge on global patterns of influenza virus infections in wild birds, discuss these patterns in the context of host ecology and in particular birds' behavior, and identify some important gaps in our current knowledge.
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| 12. |
- Verhagen, Josanne H., et al.
(författare)
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Avian influenza a virus in wild birds in highly urbanized areas.
- 2012
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Ingår i: PLOS ONE. - : Public Library of Science (PLoS). - 1932-6203. ; 7:6
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Tidskriftsartikel (refereegranskat)abstract
- Avian influenza virus (AIV) surveillance studies in wild birds are usually conducted in rural areas and nature reserves. Less is known of avian influenza virus prevalence in wild birds located in densely populated urban areas, while these birds are more likely to be in close contact with humans. Influenza virus prevalence was investigated in 6059 wild birds sampled in cities in the Netherlands between 2006 and 2009, and compared with parallel AIV surveillance data from low urbanized areas in the Netherlands. Viral prevalence varied with the level of urbanization, with highest prevalence in low urbanized areas. Within cities virus was detected in 0.5% of birds, while seroprevalence exceeded 50%. Ring recoveries of urban wild birds sampled for virus detection demonstrated that most birds were sighted within the same city, while few were sighted in other cities or migrated up to 2659 km away from the sample location in the Netherlands. Here we show that urban birds were infected with AIVs and that urban birds were not separated completely from populations of long-distance migrants. The latter suggests that wild birds in cities may play a role in the introduction of AIVs into cities. Thus, urban bird populations should not be excluded as a human-animal interface for influenza viruses.
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| 13. |
- Verhagen, Josanne H., et al.
(författare)
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Discordant detection of avian influenza virus subtypes in time and space between poultry and wild birds : Towards improvement of surveillance programs
- 2017
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Ingår i: PLOS ONE. - : Public Library of Science. - 1932-6203. ; 12:3
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Tidskriftsartikel (refereegranskat)abstract
- Avian influenza viruses from wild birds can cause outbreaks in poultry, and occasionally infect humans upon exposure to infected poultry. Identification and characterization of viral reservoirs and transmission routes is important to develop strategies that prevent infection of poultry, and subsequently virus transmission between poultry holdings and to humans. Based on spatial, temporal and phylogenetic analyses of data generated as part of intense and large-scale influenza surveillance programs in wild birds and poultry in the Netherlands from 2006 to 2011, we demonstrate that LPAIV subtype distribution differed between wild birds and poultry, suggestive of host-range restrictions. LPAIV isolated from Dutch poultry were genetically most closely related to LPAIV isolated from wild birds in the Netherlands or occasionally elsewhere in Western Europe. However, a relatively long time interval was observed between the isolations of related viruses from wild birds and poultry. Spatial analyses provided evidence for mallards (Anas platyrhynchos) being more abundant near primary infected poultry farms. Detailed year-round investigation of virus prevalence and wild bird species distribution and behavior near poultry farms should be used to improve risk assessment in relation to avian influenza virus introduction and retarget avian influenza surveillance programs.
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| 14. |
- Verhagen, Josanne H., et al.
(författare)
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Epidemiology of influenza A virus among black-headed gulls, the Netherlands, 2006-2010.
- 2014
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Ingår i: Emerging Infectious Diseases. - : Centers for Disease Control and Prevention (CDC). - 1080-6040 .- 1080-6059. ; 20:1, s. 138-141
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Tidskriftsartikel (refereegranskat)abstract
- We sampled 7,511 black-headed gulls for influenza virus in the Netherlands during 2006-2010 and found that subtypes H13 and H16 caused annual epidemics in fledglings on colony sites. Our findings validate targeted surveillance of wild waterbirds and clarify underlying factors for influenza virus emergence in other species.
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| 15. |
- Wallensten, Anders, 1974-, et al.
(författare)
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Mounting evidence for the presence of influenza A virus in the avifauna of the Antarctic region
- 2006
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Ingår i: Antarctic Science. - New York : Cambridge University Press. - 0954-1020 .- 1365-2079. ; 18:3, s. 353-356
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Tidskriftsartikel (refereegranskat)abstract
- Penguin blood samples collected at Bird Island, sub-Antarctic South Georgia, and faecal samples taken from penguins at several localities along the Antarctic Peninsula were analysed in order to investigate if influenza A virus is present in penguin populations in the South Atlantic Antarctic region. Serology was performed on the blood samples while the faecal samples were screened by a RT-PCR method directed at the matrix protein gene for determining the presence of influenza A virus. All faecal samples were negative by PCR, but the blood samples gave serologic indications that influenza A virus is present amongst these penguin species, confirming previous studies, although the virus has still not been isolated from any bird in the Antarctic region.
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| 16. |
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| 17. |
- Maltais, Anna-Karin, et al.
(författare)
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Intranasally administered Endocine™ formulated 2009 pandemic influenza H1N1 vaccine induces broad specific antibody responses and confers protection in ferrets
- 2014
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Ingår i: Vaccine. - : Elsevier BV. - 0264-410X .- 1873-2518. ; 32:26, s. 3307-15
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Tidskriftsartikel (refereegranskat)abstract
- Influenza is a contagious respiratory disease caused by an influenza virus. Due to continuous antigenic drift of seasonal influenza viruses, influenza vaccines need to be adjusted before every influenza season. This allows annual vaccination with multivalent seasonal influenza vaccines, recommended especially for high-risk groups. There is a need for a seasonal influenza vaccine that induces broader and longer lasting protection upon easy administration. Endocine™ is a lipid-based mucosal adjuvant composed of endogenous lipids found ubiquitously in the human body. Intranasal administration of influenza antigens mixed with this adjuvant has been shown to induce local and systemic immunity as well as protective efficacy against homologous influenza virus challenge in mice. Here we used ferrets, an established animal model for human influenza virus infections, to further investigate the potential of Endocine™ as an adjuvant. Intranasal administration of inactivated pandemic H1N1/California/2009 split antigen or whole virus antigen mixed with Endocine™ induced high levels of serum hemagglutination inhibition (HI) and virus neutralization (VN) antibody titers that were also cross reactive against distant swine viruses of the same subtype. HI and VN antibody titers were already demonstrated after a single nasal immunization. Upon intratracheal challenge with a homologous challenge virus (influenza virus H1N1/The Netherlands/602/2009) immunized ferrets were fully protected from virus replication in the lungs and largely protected against body weight loss, virus replication in the upper respiratory tract and pathological changes in the respiratory tract. Endocine™ formulated vaccines containing split antigen induced higher HI and VN antibody responses and better protection from body weight loss and virus shedding in the upper respiratory tract than the Endocine™ formulated vaccine containing whole virus antigen.
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| 18. |
- Veldhuis Kroeze, Edwin J. B., et al.
(författare)
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Consecutive CT in vivo lung imaging as quantitative parameter of influenza vaccine efficacy in the ferret model
- 2012
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Ingår i: Vaccine. - : Elsevier. - 0264-410X .- 1873-2518. ; 30:51, s. 7391-7394
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Tidskriftsartikel (refereegranskat)abstract
- Preclinical vaccine efficacy studies are generally limited to certain read out parameters such as assessment of virus titers in swabs and organs, clinical signs, serum antibody titers, and pathological changes. These parameters are not always routinely applied and not always scheduled in a logical standardized way. We used computed tomography (CT) imaging as additional and novel read out parameter in a vaccine efficacy study by quantifying alterations in aerated lung volumes in ferrets challenged with the 2009 pandemic A/H1N1 influenza virus.Vaccination protected from marked variations in aerated lung volumes compared to naive controls. The vaccinated group showed a daily gradual mean reduction with a maximum of 7.8%, whereas the controls showed a maximum of 14.3% reduction. The pulmonary opacities evident on CT images were most pronounced in the placebo-treated controls, and corresponded to significantly increased relative lung weights at necropsy.This study shows that consecutive in vivo CT imaging allows for a day to day read out of vaccine efficacy by quantification of altered aerated lung volumes.
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