VACCINES AGAINST COVID-19 FROM JANSSEN (JOHNSON & JOHSONS) AND SANOFI/GSK:

 

THE VACCINES FROM JANSSEN AND SANOFI/GSK (currently still under development) TO PROTECT AGAINST SARS-Cov-2 are not mRNA VACCINES, IN CONTRAST TO THE OTHER VACCINES AGAINST COVID-19 THAT ARE CURRENTLY AVAILABLE.


1.Janssen (Johnson & Johnson):

One of the candidate vaccines, the adenovirus serotype 26 (Ad26) vector-based vaccine expressing an optimized SARS-CoV-2 spike (Ad26.COV2.S) or JNJ-78436735, is now in Phase 3 of human trials. Developed by Janssen Vaccines (Johnson & Johnson) and Beth Israel Deaconess Medical Center (BIDMC), the vaccine is a single-dose human adenovirus vector vaccine.

The Ad26.COV2.S vaccine was derived from the first clinical isolate of the Wuhan strain. The Ad26 vector is used in the Ebola vaccine that was approved by the European Medicines Agency. Ad26.COV2.S is a vector-based vaccine that uses genetically modified adenovirus to introduce the genetic code for the spike protein into the cell. The vector (adenovirus) can not replicate and thus not cause disease. Same method used for registered Ebola vaccine. Approved in the EU.

Ad26-based vaccines are safe and immunogenic since they are based on Janssen's AdVac technology platform, which was also used to develop and manufacture other vaccine candidates against the Ebola virus, the human immunodeficiency virus (HIV), the respiratory syncytial virus (RSV), and the Zika virus.

The vaccine is based on a human adenovirus that has been modified to contain the gene for making the spike protein of the SARS-CoV-2 virus that causes COVID-19. The vaccine requires only one dose and does not need to be stored frozen. COVID-19 Vaccine Janssen works by preparing the body to defend itself against COVID-19. It is made up of another virus (an adenovirus) that has been modified to contain the gene for making the SARS-CoV-2 spike protein. This is a protein on the SARS-CoV-2 virus which it needs to enter the body's cells.

The cells can then use the gene to produce the spike protein. The person's immune system will recognize the spike protein as foreign and produce antibodies and activate T cells (white blood cells) to target it.

Later, if the person comes into contact with SARS-CoV-2 virus, the person's immune system will recognize the spike protein on the virus and be ready to defend the body against it. The adenovirus in the vaccine cannot reproduce and does not cause disease.

COVID-19 Vaccine Janssen is now authorized across the EU. This follows the granting of a conditional marketing authorisation by the European Commission on 11 March 2021.

Content declaration
The active substance is adenovirus type 26 which encodes SARS-CoV-2 spike glycoprotein * (Ad26.COV2-S), with at least 8.92 log10 infectious units (Inf.E) per dose of 0.5 ml. * Produced in PER.C6 TetR cell line and by recombinant DNA technology. The product contains genetically modified organisms (GMOs).

The other ingredients (excipients) are 2-hydroxypropyl-?-cyclodextrin (HBCD), citric acid monohydrate, ethanol, hydrochloric acid, polysorbate-80, sodium chloride, sodium hydroxide, trisodium citrate dihydrate, water for injections (see section 2 Covidine-19 Vaccine).

Covid-19 Vaccine Janssen contains ethanol.
This medicine contains 2 mg of alcohol (ethanol) per dose of 0.5 ml. The amount of ethanol in this medicine corresponds to less than 1 ml of beer or wine. The low amount of alcohol in this medicine does not produce any noticeable effects.


How does the Janssen vaccine work? The Janssen vaccine is a viral vector vaccine. This means it uses a virus - in this case, a version of an adenoviruses, which causes mild cold or flu symptoms in people. The company has modified this virus to include DNA that codes for the spike protein on the SARS-CoV-2 virus. This spike protein is one of the virus' identifying features for immune cells, and what the virus uses to weasel its way into our cells.

The adenovirus works its way into our cells like a virus normally would, but then injects the genetic material for the spike protein instead. Our cells do what they do best and read that DNA to make copies of the spike protein, which then trigger an immune reaction. (This function is similar to an mRNA vaccine, except the process of making the spike protein starts at the DNA versus the mRNA stage in protein translation.) Janssen's vaccine is unique among the Covid-19 vaccine candidates in that it's been tested using a single dose. Every other vaccine in the pipeline so far requires two doses.

Method
The Janssen COVID-19 vaccine will be given to you as an injection into the muscle, as a single dose. Can be stored for 12 hours at room temperature, 3 months in the refrigerator and 2 years in a standard freezer.

Johnson & Johnson is committed to making its COVID-19 vaccine available on a not-for-profit basis for emergency pandemic use.

2.Sanofi/GSK:

Sanofi's candidate COVID-19 recombinant protein vaccine:

Recombinant protein adjuvanted vaccine.

How a protein-based COVID-19 vaccine is designed to work.
Sanofi is developing a vaccine to protect against COVID-19 disease. It uses the same technology developed to produce one of our seasonal influenza vaccines. The candidate vaccine is designed to raise an immune response that will help the body fight off the SARS-CoV-2 virus. It targets a protein on the surface of the virus called the spike.

The spike protein helps the virus gain entry into a person's cells, including those in the lungs. Once inside the cell the virus replicates. It can then enter many other cells in the body. In the response to the infections, the body's immune system produces antibodies against the SARS-CoV-2 virus, which stops the virus from multiplying. A vaccine that targets the Spike protein can help the body build this defense by stimulating an infection whiteout making the person sick.

How Sanofi's candidate COVID-19 recombinant protein vaccine is made
Sanofi's candidate recombinant protein coronavirus vaccine, currently under development, uses the same technology as one of Sanofi's seasonal influenza vaccines. The flu protein is simply switched to a protein from the surface of the SARS-CoV-2 virus-the spike protein. The spike protein is a key player in helping the coronavirus get into a person's cells, including those in the lungs.

The key steps to know how Sanofi's candidate recombinant protein vaccine is designed to work

  • In the lab, scientists copy the spike protein's DNA sequence, then insert it into a circular piece of DNA called a plasmid. (This is called &dquo;recombinant DNA&dquo;, because it re-combines different segments of DNA.)

  • The plasmid transports the spike DNA sequence into a specialized virus, called baculovirus, that is used to help manufacture the vaccine.

  • Meanwhile, specialized cells in the lab are on standby, ready to act as miniature factories. The baculovirus enters these cells, which then churn out copies of the spike protein.

  • Once the cells have generated enough spike proteins, Sanofi technicians extract them from the mixture, purify them, collect them in large batches, and formulate them before dispensing them into vials.

  • This candidate vaccine is designed to be used in combination with an adjuvant: a different component of the vaccine that helps alert the body's immune system to the spike's presence and helps stimulate it to create antibodies.

  • When the vaccine is injected into the body, the spike protein is detected by the immune system, which generates antibodies that can identify and bind to it.

  • These antibodies are then available to attack the spike protein on the virus surface, if it enters the body, and help stop COVID-19 disease. The immune system responds to the vaccine and commits the spike protein to memory, so that when the body encounters the full SARS-CoV-2 virus it will remember to generate new antibodies to counter the virus. This type of memory typically allows for a vaccine to generate longer-lasting protection from disease.
  • How vaccines work
    Indeed, vaccines essentially trigger the immune system to react as if there was a pathogen present, but without causing illness.

    About the GSK / Sanofi partnership
    In the partnership between the two Companies, Sanofi provides its recombinant antigen and GlaxoSmithKline (GSK) contributes its pandemic adjuvant, both established vaccine platforms that have proven successful against influenza.

    On February 22, Sanofi and GSK announced the start of a new phase 2 study of their adjuvanted recombinant protein COVID-19 vaccine candidate.

    New Phase 2 study assesses potential for refined antigen formulation to achieve optimal immune response, including in older adults. If results are positive, Phase 3 study to start in Q2 2021, with vaccine expected to be available in Q4 2021.

    March 27th 2021

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