Vidprevtyn is a protein subunit vaccine, which means it uses harmless protein fragments which teaches the immune system how to spot and fight SARS-CoV-2 virus. It is a more traditional type of vaccine than mRNA or adenovirus vector vaccines, which carry the genetic instructions to make the nail protein into cells, where they can then be built and displayed as mumps that the immune system can find and defend against.
These types of vaccines can be stored at refrigerator temperatures, making them easier to use in areas that do not have access to ultra-cold storage. Because they rely on more well-known technology, there is hope that people who have turned down other forms of Covid-19 vaccines may find these types of vaccines more palatable.
The vaccine is given in two doses about three weeks apart. The Phase 3 trials to test the vaccine enrolled more than 10,000 adults in the United States, Asia, Africa and Latin America. A separate study assesses a third dose of the vaccine as a booster.
After two doses given to individuals without antibodies to the SARS-CoV-2 virus, the vaccine was:
- 58% effective in preventing Co
- 75% effective for preventing moderate or severe Covid-19
- 100% effective against severe Covid-19 disease, including hospitalizations
The new vaccine had lower numbers against symptomatic disease than the mRNA vaccines from Pfizer and Moderna, but it was also tested under other conditions as the new variants circulated.
“We are very pleased with this data,” said Thomas Triomphe, executive vice president at Sanofi. “No other global Phase 3 efficacy study has been conducted during this period with so many variants of concern, including Omicron, and these efficacy data are similar to recent clinical data from authorized vaccines.”
The companies said the vaccine performed well on its own and as a mix-and-match booster that encounters neutralizing antibodies 18 to 30 times when given to people who had received Pfizer, Moderna or adenovirus vector vaccines such as Johnson & Johnson and AstraZeneca shot. The manufacturers say no safety issues were identified in the trials.
A spokesman for the company says the most likely role for the vaccine in the US and European markets – where so many people have completed their initial vaccine series – will be as a booster.
Millions of doses already released
The top-line survey results were published in the company’s news releases. The manufacturers say the full results of the trials will be announced this year.
The vaccine was developed with $ 2.1 billion in funding from Operation Warp Speed, the landmark effort to accelerate effective vaccines against Covid-19 for the United States and the rest of the world. The company says it has produced and released 100 million doses and plans to deliver up to 400 million more doses.
Vidprevtyn development was delayed after results from an initial formulation showed that it did not generate a robust immune response in older adults. The companies reformulated and started testing again. The latest results come from a Phase 3 trial that started in May 2021 and reflects real tests of the shots against several variants, including Delta and Omicron, according to a Sanofi spokesman.