scholarly journals Evidence for Persistence of and Antiviral Resistance and Reassortment Events in Seasonal Influenza Virus Strains Circulating in Cambodia: FIG. 1.

2009 ◽  
Vol 48 (1) ◽  
pp. 295-297 ◽  
Author(s):  
Mathieu Fourment ◽  
Sek Mardy ◽  
Mey Channa ◽  
Philippe Buchy
2017 ◽  
Vol 114 (38) ◽  
pp. 10172-10177 ◽  
Author(s):  
Jad Maamary ◽  
Taia T. Wang ◽  
Gene S. Tan ◽  
Peter Palese ◽  
Jeffrey V. Ravetch

The main barrier to reduction of morbidity caused by influenza is the absence of a vaccine that elicits broad protection against different virus strains. Studies in preclinical models of influenza virus infections have shown that antibodies alone are sufficient to provide broad protection against divergent virus strains in vivo. Here, we address the challenge of identifying an immunogen that can elicit potent, broadly protective, antiinfluenza antibodies by demonstrating that immune complexes composed of sialylated antihemagglutinin antibodies and seasonal inactivated flu vaccine (TIV) can elicit broadly protective antihemagglutinin antibodies. Further, we found that an Fc-modified, bispecific monoclonal antibody against conserved epitopes of the hemagglutinin can be combined with TIV to elicit broad protection, thus setting the stage for a universal influenza virus vaccine.


2019 ◽  
Vol 147 ◽  
Author(s):  
Lin-Lei Chen ◽  
Wai-Lan Wu ◽  
Wan-Mui Chan ◽  
Carol H. Y. Fong ◽  
Anthony C. K. Ng ◽  
...  

Abstract Seasonal influenza virus epidemics have a major impact on healthcare systems. Data on population susceptibility to emerging influenza virus strains during the interepidemic period can guide planning for resource allocation of an upcoming influenza season. This study sought to assess the population susceptibility to representative emerging influenza virus strains collected during the interepidemic period. The microneutralisation antibody titers (MN titers) of a human serum panel against representative emerging influenza strains collected during the interepidemic period before the 2018/2019 winter influenza season (H1N1-inter and H3N2-inter) were compared with those against influenza strains representative of previous epidemics (H1N1-pre and H3N2-pre). A multifaceted approach, incorporating both genetic and antigenic data, was used in selecting these representative influenza virus strains for the MN assay. A significantly higher proportion of individuals had a ⩾four-fold reduction in MN titers between H1N1-inter and H1N1-pre than that between H3N2-inter and H3N2-pre (28.5% (127/445) vs. 4.9% (22/445), P < 0.001). The geometric mean titer (GMT) of H1N1-inter was significantly lower than that of H1N1-pre (381 (95% CI 339–428) vs. 713 (95% CI 641–792), P < 0.001), while there was no significant difference in the GMT between H3N2-inter and H3N2-pre. Since A(H1N1) predominated the 2018–2019 winter influenza epidemic, our results corroborated the epidemic subtype.


2018 ◽  
Vol 92 (22) ◽  
Author(s):  
Nicole Darricarrère ◽  
Svetlana Pougatcheva ◽  
Xiaochu Duan ◽  
Rebecca S. Rudicell ◽  
Te-Hui Chou ◽  
...  

ABSTRACT The efficacy of current seasonal influenza vaccines varies greatly, depending on the match to circulating viruses. Although most vaccines elicit strain-specific responses, some present cross-reactive epitopes that elicit antibodies against diverse viruses and remain unchanged and effective for several years. To determine whether combinations of specific H1 hemagglutinin (HA) antigens stimulate immune responses that protect against diverse H1 influenza viruses, we evaluated the antibody responses elicited by HA-ferritin nanoparticles derived from six evolutionarily divergent H1 sequences and two computationally optimized broadly reactive antigen (COBRA) HA antigens. Humoral responses were assessed against a panel of 16 representative influenza virus strains from the past 80 years. HAs from the strains A/NewCaledonia/20/1999 (NC99), A/California/04/2009 (CA09), A/HongKong/117/1977 (HK77), COBRA X6, or P1 elicited neutralization against diverse strains, and a combination of three wild-type HA or two COBRA HA nanoparticles conferred significant additional breadth beyond that observed with any individual strain. Therefore, combinations of H1 HAs may constitute a pan-H1 influenza vaccine. IMPORTANCE Seasonal influenza vaccines elicit strain-specific immune responses designed to protect against circulating viruses. Because these vaccines often show limited efficacy, the search for a broadly protective seasonal vaccine remains a priority. Among different influenza virus subtypes, H1N1 has long been circulating in humans and has caused pandemic outbreaks. In order to assess the potential of a multivalent HA combination vaccine to improve the breadth of protection against divergent H1N1 viruses, HA-ferritin nanoparticles were made and evaluated in mice against a panel of historical and contemporary influenza virus strains. Trivalent combinations of H1 nanoparticles improved the breadth of immunity against divergent H1 influenza viruses.


mBio ◽  
2015 ◽  
Vol 6 (5) ◽  
Author(s):  
Stacey Schultz-Cherry

ABSTRACT The best way to combat influenza virus infection is to prevent it. However, the continual evolution of circulating influenza virus strains and the constant threat of newly emerging viruses forces the public health community to annually update seasonal influenza vaccines while stockpiling potential pandemic virus vaccines. Thus, there is an urgent need to develop a “universal” influenza vaccine that affords protection against all strains. In their recent article, L. M. Schwartzman et al. (mBio 6:e01044-15, 2015, doi:10.1128/mBio.01044-15) demonstrated that intranasal immunization of mice with a cocktail of viral-like particles (VLPs) expressing distinct influenza virus hemagglutinin (HA) proteins can broadly protect against infection not only with the same viral strains but also with unrelated strains. These findings suggest a promising strategy for developing a broadly protective “universal” influenza vaccine.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
James D. Allen ◽  
Ted M. Ross

AbstractWhile vaccines remain the best tool for preventing influenza virus infections, they have demonstrated low to moderate effectiveness in recent years. Seasonal influenza vaccines typically consist of wild-type influenza A and B viruses that are limited in their ability to elicit protective immune responses against co-circulating influenza virus variant strains. Improved influenza virus vaccines need to elicit protective immune responses against multiple influenza virus drift variants within each season. Broadly reactive vaccine candidates potentially provide a solution to this problem, but their efficacy may begin to wane as influenza viruses naturally mutate through processes that mediates drift. Thus, it is necessary to develop a method that commercial vaccine manufacturers can use to update broadly reactive vaccine antigens to better protect against future and currently circulating viral variants. Building upon the COBRA technology, nine next-generation H3N2 influenza hemagglutinin (HA) vaccines were designed using a next generation algorithm and design methodology. These next-generation broadly reactive COBRA H3 HA vaccines were superior to wild-type HA vaccines at eliciting antibodies with high HAI activity against a panel of historical and co-circulating H3N2 influenza viruses isolated over the last 15 years, as well as the ability to neutralize future emerging H3N2 isolates.


2008 ◽  
Vol 15 (8) ◽  
pp. 1171-1175 ◽  
Author(s):  
Tjitske de Boer ◽  
Jaap T. van Dissel ◽  
Taco W. J. Kuijpers ◽  
Guus F. Rimmelzwaan ◽  
Frank P. Kroon ◽  
...  

ABSTRACT To investigate whether protective immune responses can be induced in the absence of normal interleukin-12/23/gamma interferon (IL-12/23/IFN-γ) axis signaling, we vaccinated with the seasonal influenza virus subunit vaccine two patients with complete IL-12/23 receptor β1 (IL-12/23Rβ1) deficiencies, two patients with partial IFN-γ receptor I (pIFN-γRI) deficiencies, and five healthy controls. Blood samples were analyzed before, 7 days after, and 28 days after vaccination. In most cases, antibody titers reached protective levels. Moreover, although T-cell responses in patients were lower than those observed in controls, significant influenza virus-specific T-cell proliferation, IFN-γ production, and numbers of IFN-γ-producing cells were found in all patients 7 days after the vaccination. Interestingly, influenza virus-specific IFN-γ responses were IL-12/23 independent, in striking contrast to mycobacterium-induced IFN-γ production. In conclusion, influenza virus vaccination induces IL-12/23-independent IFN-γ production by T cells and can result in sufficient humoral protection in both IL-12/23Rβ1- and pIFN-γRI-deficient individuals.


1982 ◽  
Vol 28 (7) ◽  
pp. 809-814 ◽  
Author(s):  
P. Diaz-Rodriguez ◽  
A. Boudreault

As reported previously, attenuated stable inhibitor-resistant influenza viruses can be screened by a 50% ciliary activity inhibition test in ferret tracheal organ cultures. This test was further applied to 5 attenuated cold-adapted influenza strains and to 11 strains with known a percentage of RNA–RNA hybridization with the parental A/PR/8/34 (H0N1) virus strain. Again, with one exception, attenuated strains could be clearly differentiated from virulent ones. It was concluded that virulence of influenza strains for man can be detected using this test regardless of the techniques used to prepare attenuated variants. A preliminary screening of attenuated candidates for live influenza vaccines can be achieved with confidence on ferret tracheal organ cultures.


Sign in / Sign up

Export Citation Format

Share Document