Just when you thought it couldn't get worse, along comes self-amplifying mRNA for use in "vaccination" programs

What could possibly go wrong?

On September 27 Gritstone bio (GRTS.O) secured a $433 million contract awarded by the Biomedical Advanced Research and Development Authority (BARDA) to conduct a mid-stage study of its self-amplifying mRNA (samRNA) COVID-19 genetic vaccine candidate.

Source: https://www.reuters.com/business/healthcare-pharmaceuticals/gritstone-bio-wins-433-million-us-award-covid-vaccine-study-2023-09-27/

And they are not the only company that has received funding to explore this technology for genetic vaccine development.

Source: https://www.businesswire.com/news/home/20221129006144/en/UTMB-and-HDT-Bio-awarded-prototype-project-funding-worth-up-to-87.4M-from-the-U.S.-government-to-develop-saRNA-vaccine-technology

The University of Texas Medical Branch (UTMB) has been awarded a project agreement worth up to $87.4 million by the U.S. Department of Defense’s (DOD) Joint Program Executive Office for Chemical, Biological, Radiological and Nuclear Defense (JPEO-CBRND) and the U.S. Department of Health and Human Services’ (HHS) Biomedical Advanced Research and Development Authority (BARDA) within the Administration for Strategic Preparedness and Response (ASPR), through the Medical CBRN Defense Consortium (MCDC) Other Transaction Authority (OTA), for the development of a vaccine technology against advanced and emerging viral threats. Two deadly viruses of significance to military personnel will be targeted for vaccine protection. These are Crimean-Congo hemorrhagic fever virus (CCHFV) and Nipah virus (NiV).

Who is Gritstone Bio?

Gritstone Bio was founded in August 2015 as Gritstone Oncology, Inc., and is based in Emeryville, California. It went public in September 2021 when it raised $55.0 million from the sale of 5,000,000 shares.

The company started with a focus on tumor-specific neoantigens. Gritstone is best known for its work in cancer vaccines, with its lead program, dubbed GRANITE, in phase 2/3 trials for metastatic, microsatellite-stable colorectal cancer. However, the GRANITE trial, is not expected to read out until the first quarter of 2024.

So like the previously unproven company Moderna, Gritstone Bio has never had a product to market and is therefore not only unproven in the market but does not have a focus on viral diseases.

Despite this, Gritstone Bio obtained patents for samRNA vaccine platform technology for application in cancer treatment and infectious diseases in December 2022.

Source: https://www.bloomberg.com/press-releases/2022-12-13/gritstone-bio-granted-two-new-u-s-patents-for-self-amplifying-mrna-samrna#:~:text=About%20Self%2Damplifying%20mRNA%20

U.S. Patent No. 11,510,973 includes
claims covering antigen-encoding samRNA vectors and has broad applicability
across Gritstone’s candidates in oncology and infectious disease.

“Self-amplifying mRNA (samRNA) is increasingly being recognized for its benefits over first-generation mRNA, and our new patents reflect the leadership position we believe we have established in this rapidly growing space,” said Andrew Allen, M.D., Ph.D., Co-founder, President, and Chief Executive Officer of Gritstone.

What is self-amplifying mRNA (samRNA)?

There are currently two different types of synthetic RNA genetic vaccines: conventional mRNA and self-amplifying mRNA (samRNA). Conventional mRNA strategies (also referred to as nonreplicating or non-amplifying mRNA) against infectious diseases and cancers has been investigated in several preclinical and clinical trials. This is the current type of genetic vaccine that was rolled out against COVID-19 in 2020.

According to researchers antigen expression is proportional to the number of conventional mRNA transcripts successfully delivered during injection. Given that immunity using the conventional mRNA genetic vaccines rapidly wanes, achieving adequate expression for protection or immunomodulation may thus require large doses or repeat administrations. samRNA vaccines, which are genetically engineered replicons derived from self-replicating single-stranded RNA viruses, address this limitation.

Like conventional mRNA genetic vaccines, samRNA vaccines use the host cell’s transcription system to produce target antigens to stimulate adaptive immunity. Unlike conventional mRNA, samRNA replicates once in the cell, creating copies of the original strand of RNA. samRNA vaccines—in which RNAs encode viral replicase genes in addition to antigen genes—promise improved potency and durability due to both the amplification of the RNA in vivo after delivery and the adjuvanting properties of dsRNA and replication intermediates. In other words, the samRNA are replication competent so they will continue to produce mRNA for further translation to protein. In addition, the dsRNA produced during replication can on their own induce an immune response.

Source: https://www.nature.com/articles/s41434-020-00204-y

As a result of their self-replicative activity, samRNAs can be delivered at lower concentrations than conventional mRNA vaccines to achieve comparable antigen expression. samRNAs have shown enhanced antigen expression at lower doses compared to conventional mRNA.

Source: https://www.biontech.com/int/en/home/research-and-innovation/drug-classes/mrna.html#accordion-89e0f1a6e9-item-51ff59971a

“Gritstone’s samRNA vectors enable extended duration and magnitude of antigen expression, in an immunostimulatory context, which together can drive more potent and durable induction of neutralizing antibodies and T cell immunity. In addition, Gritstone’s samRNA vectors allow for large cassettes, providing substantial target antigen capacity and flexibility.”

What could possibly go wrong?

Conventional and synthetic samRNA vaccines are essentially produced in the same manner. Briefly, an mRNA expression plasmid (pDNA) encoding a DNA-dependent RNA polymerase promoter (typically derived from the T7, T3, or SP6 bacteriophages) and the RNA vaccine candidate is designed as a template for in vitro transcription. Therefore, their use will induce similar issues.

Sequencing of bivalent Moderna and Pfizer mRNA vaccines reveals nanogram to microgram quantities of expression vector dsDNA per dose

Not only has it recently come to light that the the mRNA genetic vaccines are heavily contaminated with plasmid DNA (study showing this can be found here https://osf.io/b9t7m/) but, mRNA vaccination was shown to stimulate germinal centers in lymph nodes containing vaccine mRNA for up to 8 weeks post vaccination in some cases. NOTE: Researchers did not assess time points later than 60 days after vaccination so further studies are needed to determine how long the mRNA actually persists after injection.

Source: https://www.cell.com/cell/pdf/S0092-8674(22)00076-9.pdf

Histological analysis of draining LN shows marked impairment of GCs in severe COVID-19 compared with mRNA vaccination, higher quantities, and persistence of spike antigen accumulated in the GCs of mRNA vaccinees and detectable vaccine RNA in GCs for up to 2 months post-second dose.

Another study assessing immune activation after mRNA injection in healthy volunteers demonstrated that spike protein was circulating for at least 4 months after injection. In addition, mice immunized with circulating exosomes carrying spike protein isolated from vaccinated individuals demonstrated that these exosomes are immunogenic, meaning they were also able to induce an immune response. But again time points longer than 4 months were not assessed in this study so further studies are needed to know exactly how long the spike protein can circulate in vaccinated individuals.

So if the mRNA and spike protein from conventional mRNA genetic vaccines are persisting in the body for at least several months following injection, why would it be necessary to enable higher levels of protein expression and have it last even longer?

Persistent antigen stimulation is a problem

Chronic immune stimulation in the setting of uncleared viremia eventually results in a phenomenon known as immune exhaustion, wherein effector cells lose functions and proliferative capacity. Chronic antigenic stimulation causes effector cells to persist, but become unresponsive to further stimulation. In other words persistent stimulation with an antigen leads to immune tolerance where the immune system no longer responds to the antigen. T cell exhaustion is characterized by failure to respond to a persistent antigen and is a hallmark of chronic infections and cancer.

In addition, immune exhaustion is associated with chronic fatigue syndrome most recently renamed “long-COVID”. In fact, new data suggests genetic vaccines are making long COVID worse.

A recent study by Diexer et. al. demonstrated that the risk of developing long-COVID did not differ based on the vaccination status (among those who had been infected). The study determined that participants infected with the Omicron variant had the lowest risk of developing long-COVID, followed by the Delta, Alpha, and Wild-type variants. The lowest risk group was the unvaccinated who had their first infection with Omicron. There was strong evidence that the risk of developing long-COVID was substantially lower among those who had had previous infections and vaccination offered no meaningful protection against developing long-COVID upon subsequent infection.

Despite all this, researchers continue moving forward with samRNA genetic vaccine development

A phase I first-in-human dose-ranging trial of a samRNA COVID-19 vaccine candidate LNP-nCoVsaRNA, was conducted at Imperial Clinical Research Facility, and participating centers in London, UK, between 19 June to 28 October 2020. The trial evaluated six dose levels of LNP-nCoVsamRNA as two intramuscular injections given four weeks apart.

Adverse events (AEs) were collected for one week from enrolment, with follow-up at regular intervals (1-8 weeks). They claim the genetic vaccine was well tolerated with no serious adverse events related to vaccination. However, of the 137 (71%) participants reporting 394 AEs, 25 had a moderately severe event, and six had a severe or worse event with two of the six hospitalized. The study is on-going, and participants will be followed for 1 year so, time will tell.