FluBlok, a recombinant hemagglutinin influenza vaccine

Protein Sciences Corporation, 1000 Research Parkway, Meriden, CT 06450, USA.
Influenza and Other Respiratory Viruses (Impact Factor: 2.2). 12/2008; 2(6):211-9. DOI: 10.1111/j.1750-2659.2008.00053.x
Source: PubMed


FluBlok, a recombinant trivalent hemagglutinin (HA) vaccine produced in insect cell culture using the baculovirus expression system, provides an attractive alternative to the current egg-based trivalent inactivated influenza vaccine (TIV) manufacturing process. FluBlok contains three times more HA than TIV and does not contain egg-protein or preservatives. This review discusses the four main clinical studies that were used to support licensure of FluBlok under the 'Accelerated Approval' mechanism in the United States.

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Available from: Peter Patriarca, Feb 16, 2015
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    • "Live attenuated influenza A vaccines (LAIV) are 0264-410X/Published by Elsevier Ltd. generated with the HA and NA genes from the vaccine target and the internal protein genes from a temperature sensitive (ts), coldadapted (ca), attenuated (att) master donor virus, either influenza A/Ann Arbor/6/60 ca (AA ca) [4] or influenza A/Leningrad/47/57 ca [5]. Recombinant HA vaccines are generated from baculovirus expressed HA [6]. At present, it takes several months from identifying a target strain to distributing a vaccine. "
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    ABSTRACT: Codon-pair bias de-optimization (CPBD) of viruses involves re-writing viral genes using statistically underrepresented codon pairs, without any changes to the amino acid sequence or codon usage. Previously, this technology has been used to attenuate the influenza A/Puerto Rico/8/34 (H1N1) virus. The de-optimized virus was immunogenic and protected inbred mice from challenge. In order to assess whether CPBD could be used to produce a live vaccine against a clinically relevant influenza virus, we generated an influenza A/California/07/2009 pandemic H1N1 (2009 pH1N1) virus with de-optimized HA and NA gene segments (2009 pH1N1-(HA+NA)(Min)), and evaluated viral replication and protein expression in MDCK cells, and attenuation, immunogenicity, and efficacy in outbred ferrets. The 2009 pH1N1-(HA+NA)(Min) virus grew to a similar titer as the 2009 pH1N1 wild type (wt) virus in MDCK cells (∼10(6)TCID50/ml), despite reduced HA and NA protein expression on western blot. In ferrets, intranasal inoculation of 2009 pH1N1-(HA+NA)(Min) virus at doses ranging from 10(3) to 10(5) TCID50 led to seroconversion in all animals and protection from challenge with the 2009 pH1N1 wt virus 28 days later. The 2009 pH1N1-(HA+NA)(Min) virus did not cause clinical illness in ferrets, but replicated to a similar titer as the wt virus in the upper and lower respiratory tract, suggesting that de-optimization of additional gene segments may be warranted for improved attenuation. Taken together, our data demonstrate the potential of using CPBD technology for the development of a live influenza virus vaccine if the level of attenuation is optimized.
    Full-text · Article · Dec 2015 · Vaccine
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    • "This process is iterative and often time-consuming, and occasionally requires selection of an HA that is less than optimally matched to the HA of predominantly circulating strains [5]. The development of recombinant HA-based vaccines offer the potential for overcoming these limitations [6], but some observers remain concerned that HA-based vaccines could be inadequately effective, especially in vulnerable populations such as the elderly, who appear to be a critical target population for A(H7N9)-mediated severe disease [7]. An A(H7N9) vaccine candidate was constructed from full length, unmodified influenza hemagglutinin (HA) and neuraminidase (NA) from the A/Anhui/1/2013 strain and the matrix 1 (M1) protein from the A/Indonesia/05/2005 (H5N1) strain. "
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    ABSTRACT: The recent emergence of severe human illness caused by avian-origin influenza A(H7N9) viruses in China has precipitated a global effort to rapidly develop and test vaccine candidates. To date, non-A(H7N9) H7 subtype influenza vaccine candidates have been poorly immunogenic and difficulties in production of A(H7N9) virus seed strains have been encountered. A candidate recombinant A(H7N9) vaccine consisting of full length, unmodified hemagglutinin (HA) and neuraminidase (NA) from the A/Anhui/1/2013 and the matrix 1 (M1) protein from the A/Indonesia/05/2005 (H5N1) were cloned into a baculovirus vector. Baculovirus infected Spodoptera frugiperda (Sf9) insect cells secreted virus like particles (VLP) composed of HA, NA, and M1 that resemble mature influenza virions. Genetic construction of vaccine from acquisition of an H7N9 genomic sequence to production of A(H7N9) VLP occurred in 26 days. The immunogenicity and efficacy of A/Anhui/1/2013 (H7N9) VLP vaccine administered on days 0 and 14 were evaluated in a lethal wild-type challenge Balb/c mouse model. Control groups included a non-homologous H7 vaccine (A/chicken/Jalisco/CPA1/2012 (H7N3)-VLP), and A/Indonesia/05/2005 (H5N1)-VLP, or placebo. All vaccines were administered with or without ISCOMATRIX. A(H7N9) VLP elicited hemagglutination-inhibition (HAI) antibody titers of ≥1:64 against the homologous virus, cross-reactive HAI against the heterologous A(H7N3), and 3- to 4-fold higher HAI responses in corresponding ISCOMATRIX subgroups. Similarly, all doses of H7N9 VLP elicited anti-neuraminidase (NA) antibody, with 3- to 4-fold higher responses measured in the corresponding ISCOMATRIX subgroups. The non-homologous H7 vaccine induced both H7N3 and H7N9 HAI but no N9 anti-NA antibodies. A lethal murine wild-type A/Anhui/1/2013 (H7N9) challenge demonstrated 100% survival of all animals receiving A(H7N9) and A(H7N3) vaccine, versus 0% survival in A(H5N1) vaccine and placebo groups. Together, the data demonstrate that recombinant H7N9 vaccine can be rapidly developed that was immunogenic and efficacious supporting testing in man as a pandemic influenza H7N9 vaccine candidate.
    Full-text · Article · Jul 2013 · Vaccine
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    • "The production of purified recombinant hemagglutinin (rHA) subunit vaccines via the baculovirus expression vector system (BEVS) is a leading alternative platform for influenza vaccine manufacture. The most advanced influenza vaccine candidate produced using this technology (under the trade name Flublok®) is a trivalent composition of three rHA proteins corresponding to the full length HA proteins of the seasonally circulating influenza strains [8-11]. Clinical trials of Flublok have demonstrated that the vaccine is well-tolerated, immunogenic (as assessed by the induction of hemagglutination inhibiting [HAI] antibodies), and provides protection against drifted influenza viruses [8-10]. "
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    ABSTRACT: Background The recent H1N1 influenza pandemic illustrated the shortcomings of the vaccine manufacturing process. The A/California/07/2009 H1N1 pandemic influenza vaccine or A(H1N1)pdm09 was available late and in short supply as a result of delays in production caused by low yields and poor antigen stability. Recombinant technology offers the opportunity to shorten manufacturing time. A trivalent recombinant hemagglutinin (rHA) vaccine candidate for seasonal influenza produced using the baculovirus expression vector system (BEVS) was shown to be as effective and safe as egg-derived trivalent inactivated vaccine (TIV) in human clinical studies. In this study, we describe the characterization of the A/California/07/2009 rHA protein and compare the H1N1 pandemic rHA to other seasonal rHA proteins. Results Our data show that, like other rHA proteins, purified A/California/07/2009 rHA forms multimeric rosette-like particles of 20–40 nm that are biologically active and immunogenic in mice as assayed by hemagglutination inhibition (HAI) antibody titers. However, proteolytic digest analysis revealed that A/California/07/2009 rHA is more susceptible to proteolytic degradation than rHA proteins derived from other seasonal influenza viruses. We identified a specific proteolytic site conserved across multiple hemagglutinin (HA) proteins that is likely more accessible in A/California/07/2009 HA, possibly as a result of differences in its protein structure, and may contribute to lower antigen stability. Conclusion We conclude that, similar to the recombinant seasonal influenza vaccine, recombinant A(H1N1)pdm09 vaccine is likely to perform comparably to licensed A(H1N1)pdm09 vaccines and could offer manufacturing advantages.
    Full-text · Article · Oct 2012 · BMC Biotechnology
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