Developing Plant-Based Vaccines and Therapeutics for COVID-19 and Beyond
In an interview withTechnology Networks,Dr.Kathleen Hefferon, a microbiologist from Cornell University, highlighted how and why plant-derived vaccines are being designed to prevent diseases including Ebola, Middle East respiratory syndrome (MERS) and coronavirus disease (COVID-19).
“Traditional vaccines can be very expensive and in short supply,” Dr. Hefferon pointed out.
In contrast to traditional vaccines, plant-based vaccines do not require needles, syringes or specialized training for theiradministration. Quite often, they can be stored ambiently, reducing the need for expensive cold storage systems. As such, they can help to remove some of the roadblocks associated with large-scale vaccination programs in developing countries.
Hefferon highlighted how “plants can be used to enhance the availability of inexpensive pharmaceuticals to even the most remote of places”. With only10.6% of peoplein low-income countries having received at least their first dose of a COVID-19 vaccine (as of February 2022), initiating vaccine rollout to remote locations is crucial.
“Plant-made vaccines and other pharmaceuticals can provide a unique opportunity to make an impact on global health,”–Dr. Kathleen Hefferon.
Hefferon’s latest work involves producing the SARS-CoV-2 spike protein in plants for use as a vaccine or as a diagnostic. The spike protein is the “major antigen capable of producing a robust immune response” against the virus.1The team modified the spike protein to ensure its stability when expressed in plants and to enable it to be purified. “We’ve added some prolines into a furin domain, which helps stabilize the [spike protein] trimer,” she explains. “We replaced [the transmembrane domain] with a KDEL motif, which is an endoplasmic reticulum retainer.”
The spike protein open reading frame was then inserted into a geminivirus, which is used to infect plants and causes transient expression of the virus transgene.
The spike protein produced by the plants can then be used to “make a cheap vaccine for people around the world”.
At the time of writing, two biopharma companies have enteredplant-based COVID-19 vaccinesinto clinical trials.
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DuringTechnology Networks’2021Advances in Drug Discovery & Developmentonline symposium,Hefferon讨论她的最近的研究集中在德西gning plant virus nanoparticles to target cancer cells and highlighted how plant viruses can be used as expression vectors to produce pharmaceuticals. You can watch her presentation below.
Ebola virus disease (EVD)in humans can be caused by four different viruses from theEbolavirusgenus. The majority of Ebola outbreaks and cases have been in Africa. The largestoutbreaksoccurred in 2014 and 2018 in West Africa and the eastern Democratic Republic of the Congo, respectively. The virus spreads through direct contact with blood or bodily fluids of a person who is sick with or has died from EVD. There are currently two monoclonal antibody-based treatments available,InmazebandEbanga. Both treatments are designed for use in patients withZaire ebolavirusinfection. Ebanga is a single monoclonal antibody that prevents virus binding to the cell receptor. Inmazeb is a combination of three monoclonal antibodies that simultaneously bind to the virus glycoprotein. A vaccine that protects against the most lethal species of ebolavirus hasbeen approvedfor use in the US.
Middle East respiratory syndrome (MERS)is caused by a coronavirus infection and was first reported in Saudi Arabia in 2012. Since then, cases have been reported in 27 countries across the Arabian Peninsula.2The largest outbreak outside of the Peninsula occurred in theRepublic of Korea, in 2015. Transmission is through close contact with an infected person. There are currently no specifictreatmentsfor MERS, and vaccines are inclinical trials.
有限公司ronavirus disease (COVID-19)is caused by infection with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Thefirst casesof COVID-19 were reported in China in 2019 and the virus has since spread worldwide.Numerous vaccineshave been developed and administered, with WHO emphasizing the importance ofvaccine equity.
References:
- Venkataraman S, Hefferon K, Makhzoum A, Abouhaidar M. Combating human viral diseases: Will plant-based vaccines be the answer?Vaccines.2021;9(7):761. doi:10.3390/vaccines9070761
- Xu J, Jia W, Wang P, et al. Antibodies and vaccines against Middle East respiratory syndrome coronavirus.Emerg Microbes Infect. 2019;8(1):841-856. doi:10.1080/22221751.2019.1624482
