Sanofi’s adjuvanted recombinant protein 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.
Sanofi and GSK announced on May 27 the start of a pivotal phase 3 clinical trial for their COVID-19 recombinant vaccine candidate which, in phase 2 initial results shared May 17, demonstrated strong immune responses across all adult age groups. In parallel, Sanofi and GSK intend to conduct booster studies to assess the ability of a lower dose of the vaccine to generate a strong booster response regardless of the initial vaccine platform received. For more information, see our initial phase 2 results press release and phase 3 press release. Pending positive phase 3 outcomes and regulatory reviews, the vaccine is expected to be approved in the fourth quarter of 2021.
How is Sanofi’s candidate COVID-19 recombinant protein vaccine made?
Sanofi’s recombinant protein COVID-19 vaccine candidate uses the same technology as one of Sanofi’s seasonal influenza vaccines. The new 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 the process 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 Sanofi teams seek to make a new vaccine, they look to answer one simple question: Can the vaccine do what they expect it to do? In other words, they 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.