Plant-based vaccine manufacturing for influenza, implications for future vaccines – medical bags

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Currently, the development of vaccines for influenza and other viruses usually depends on egg-based manufacturing. This approach, and the new technique of vaccine production in cell cultures, carries the risk of mutations that may decrease the efficacy and immunity of vaccines. Additionally, greater production speed and capacity are required to enable adequate epidemic and epidemic response.

An emerging body of research sheds light on plant-based vaccine manufacturing as a possible solution to some of these limitations. In a recent issue of KnifeInvestigators at the McGill University Health Center’s Research Institute in Montreal, Quebec, and Medicago Inc., a Quebec-based biopharmaceutical company, described the results of 2 randomized, observer-blind stage 3 evaluations of the efficacy of a recombinant quadrivalent virus . Like Particle (QVLP) Made in Influenza Vaccine Nicotiana BentamianaAs a relative of the common tobacco plant.1 These studies represent the first major trials of any plant-derived human vaccine.

One trial tested the vaccine in adults between the ages of 18–64 ( identifier: NCT03301051), While other trials included adults 65 and older. NCT03739112) In North America, Asia and Europe. Participants at both groups were generally required to be healthy at baseline. The studies were conducted during the 2017–2018 and 2018–2019 influenza seasons, respectively.

In the first trial, 5077 individuals were assigned to the QVLP vaccine group and 5083 to a placebo group. In the final per-protocol analysis, the groups consisted of 4814 and 4812 participants, respectively. The primary outcome was to prevent a vaccine of 70% complete efficacy, to prevent “laboratory-confirmatory, respiratory disease resulting from antigenically influenza strains,” which the study did not complete (35.1%; 95% CI, 17.9% –48.7%) Serious adverse events occurred in 1.1% of the QVLP group and 1.0% of the placebo group; 0.1% of each group experienced severe treatment-related or treatment-emergent adverse events.

In the second trial, 6396 participants were assigned to receive the QVLP vaccine and 6398 were assigned to receive the quadrivalent inactivated vaccine (QIV). The final per-protocol analysis included 5996 and 6026 participants, respectively. The primary outcome was the relative efficacy of the QVLP vaccine against laboratory-confirmed influenza-like disease caused by any strain of influenza, with a relative efficacy of 8.8% (95% CI, -16.7% to 28.7%). Was found. Serious adverse events occurred in 4.1% of the QVLP group and 8.2% of the QIV group; 0.1% of each group experienced severe treatment-related or treatment-emergent adverse events.

These results indicate that while the “QVLP vaccine did not meet the test of success for the primary endpoint at 18–64 years of age,” [the] The vaccine may provide protection against diseases such as respiratory disease and influenza. The vaccine efficacy estimate is similar to other licensed vaccines on the market. The findings also suggest that the vaccine was well tolerated, with a favorable safety profile in both studies.

In addition to influenza vaccines in these trials, Medicago Inc. recently reported promising Phase 1 results of a similar production Vaccination Candidate for severe acute respiratory virus coronavirus 2 (SARS-CoV-2). To combat the Coronavirus Disease 2019 (COVID-19) epidemic, Medicago Inc. stated that their vaccines “induced strong antibodies and cellular immune responses after 2 doses”, as stated in a press release.2 “The coronavirus-like particle COVID-19 vaccine candidate (CoVLP) is composed of recombinant spike (S) glycoproteins that are expressed as virus-like particles (VLPs).” The company is now conducting phase 2/3 trials of CoVLP, using the GlaxoSmithKline-owned epidemic and plans to submit the results for regulatory review in 2021.3,4

To learn more about plant-derived vaccine manufacturing, we interviewed Ed Rybicki, PhD, professor and director Biopharming Research Unit In the Department of Molecular and Cell Biology at the University of Cape Town in South Africa. His team has been investigating these techniques for almost 2 decades.

What is involved in plant-based manufacturing of vaccines, and what are some of the benefits of this method?

Dr. Rybiki: This is a big topic, but basically it involves using plants (usually) En bantamiana) To produce the protein required in a subunit vaccine. This is done either by making plants transgenic with a foreign gene inserted into the genome or – more recently – using a bacterium called Agrobacterium tomefaciens To transfer the recombinant DNA encoding gene (s) of interest in normal plants for transient expression.

The advantage of this technique is that one can go from having a gene sequence – for example, the SARS-CoV-2 S protein – to synthesize a gene, by cloning it into agro, while being very large, with a lot of it in it. Contains protein. Small amounts of agro, and are used to plant genes in large numbers (which can be kept as standby biomass, as they are cheap to grow) give you protein a week or so later. For. Medicago Inc. did so in 20 days for the SARS-2S.

The benefits include the fastest scale time for any production method, the much faster preparation of cloned DNA to do it, and the much cheaper upstream cost than any of the stainless steel fermentation methods. So, this is a good epidemic response technology!

What is the significance of the current findings by Ward, et al?

Dr. Rybiki: The findings suggest that a plant-derived candidate 4-valent seasonal influenza vaccine is at least on par with conventional egg-bound vaccines, and likely elicits cellular responses in the form of virus-like particles rather than sub-proteins. Better to do. There are no viable VLP-based flu vaccines available that are made any other way. Clinical trial results established the Medicago flu vaccine candidate as a viable alternative to traditional offerings, and in addition, one that may be too early for the transformation of influenza virus strains as opposed to egg production, Which includes a change of 6 months.

What are the potential implications of this technique for future vaccine formulation?

Dr. Rybiki: A possible implication is that subunit vaccines for hepatitis B, as well as papillomaviruses, which we have worked on here (HPV), can be produced more cheaply and conveniently in plants because the proof of concept is already in place. Have been made. In addition, flexible scaling of production volumes can have significant benefits in epidemic and pandemic response as compared to traditional production methods. Plant-based vaccine manufacturing could potentially expand the range of available human and animal vaccines and rapidly increase response capacity.

Disclosure: Ed Ribiki, PhD Announces Affiliation with Medicago Inc.

The reference

1. Ward BJ, Makarkov A, Segin A, et al. Efficacy, immunity, and protection of plant-derived, quadrupedal, virus-like particle influenza in adults (18–64 years) and older adults (years65 years): ic65 years: two multicultural, randomized phase 3 finalists. Knife. 2020; 396 (10261): 1491–1503. doi: 10.1016 / S0140-6736 (20) 32014-6

2. Medicago. Press release: Medicago announces positive Phase 1 results for its COVID-19 vaccine candidate. Published online on November 10, 2020. Accessed online 4 January 2021.

3. Medicogo. Press release: Medicago and GSK announced a 2/3 phase closure test, including COVID-19 vaccine candidates. Published online on November 12, 2020. Accessed online 4 January 2021.

4. Medicago. Medicago Development Program: COVID-19. Accessed online on 4 January 2021.

Additional Reading Tips

1. Ryabi EP. Molecular farming plants of virus-like nanoparticles as vaccines and reagents. Wiley Interdisciples Rev. Nanomed Nanobiotechol. 2020; 12 (2): e1587. doi: 10.1002 / wnan.1587

2. Rybki e. Plant-derived vaccines and reagents for SARS-CoV-2 in South Africa. Virology. Accessed online on 4 January 2021.

3. Rosels-Mendoza S, Merquez-Escobar VA, Gonzalez-Ortega O, Nieto-Gómez R, Arevalo-Villalobos G. What does plant-based vaccine technology provide for the fight against COVID-19? Vaccines (Basel). 2020; 8 (2): 183. doi: 10.3390 / vaccines8020183

4. Rockman S, Laurie KL, Parkes S, Wheatley A, Barr IG. New techniques for influenza vaccines. Microorganisms. 2020; 8 (11): 1745. doi: 10.3390 / microbe 8111745

5. Dhama K, Knutson S, Iqbal Yatu M, et al. Plant-based vaccines and antibodies to combat COVID-19: current status and prospects. We inoculate. 2020; 16 (12): 2913–2920. doi: 10.1080 / 21645515.2020.1842034

This article originally appeared on Infectious disease consultant

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