Our adjuvanted recombinant protein COVID-19 vaccine candidate is based on innovative and proven manufacturing technology. It is being developed in collaboration with the US BARDA and with GSK for its pandemic adjuvant platform.
On December 15th, Sanofi and GSK announced positive preliminary results of a study investigating the safety and immune response with their vaccine candidate as a booster regardless of primary vaccine received (mRNA or adenovirus vector based vaccines).
Sanofi continues its ongoing phase 3 trial of the vaccine following a recommendation from the Data Safety and Monitoring Board (DSMB), an independent data oversight body. The DSMB identified no safety concerns and recommended the trial continue into early 2022 to collect and provide the data necessary for regulatory submissions.
In addition to these clinical trials, recently published preclinical data indicated that the candidate vaccine has the potential to strongly boost immune responses following vaccination from many of the currently approved vaccines and against a broad range of variants.
How is the recombinant protein vaccine made?
Our recombinant protein COVID-19 vaccine candidate uses the SARS-CoV-2 virus spike protein as the vaccine antigen to help the body recognize and ideally fight off the real virus if a person becomes infected. The spike protein helps the coronavirus get into a person's cells, including those in the lungs.1 Here's how it works:
- 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 "recombinant DNA", 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 Clinical Trials Work for the Adjuvanted Recombinant protein COVID-19 vaccine candidate
When we seek to make a new vaccine, we look to answer one simple question: Can the vaccine do what we expect it to do? In other words, we aim to demonstrate that our COVID-19 vaccine meets the specific medical objectives set when given to the people who need it most. This is our process for study of our adjuvanted recombinant protein vaccine candidate.