Novavax: what differentiates the new vaccine authorized in Europe from the previous ones

And five. The European Union authorized this Monday for people over 18 years of age the vaccine against Covid-19 developed by the American laboratory Novavax, a few hours after the approval of the European Medicines Agency. With this new serum, Member States now have five vaccines in their arsenal to combat the pandemic: Pfizer-BioNTech, Moderna, AstraZeneca, Johnson & Johnson and the latest Novavax. The European Commission has already signed a contract with Novavax for the advance purchase of 200 million doses of its vaccine once it has been approved by the EMA.

• Different technology

This is one of the characteristics that could change the rules of the game among the latest refractory to the Covid-19 vaccine. Novavax’s vaccine, called Nuvaxovid, is, like the widely used childhood vaccines, a so-called “subunit” vaccine, based on proteins that trigger an immune response, without viruses. The technology is similar to that used in the decades-old hepatitis B and pertussis vaccines that are widely used around the world.

Pfizer and Moderna are messenger RNA vaccines, an innovative technology that injects chains of genetic instructions into the body that tell a patient’s cells what to do to fight disease. One of the earliest arguments from vaccine and anti-vax rejects is that RNA technology is still in the experimental stage. AstraZeneca and Johnson & Johnson, meanwhile, use an innovative viral vector technology: they take as a carrier a very common type of virus called adenovirus, which has been modified to carry genetic information in the body to fight Covid.

• Easier transport and storage

Serum can be stored at 2-8 ° C, which could facilitate its distribution, especially in less developed countries. The Covax system got it right. Last February, the American company Novavax pledged to make 1,100 million doses of its vaccine available to the international vaccination program.

“This agreement allows the Covax Facility to move closer to its goal of delivering two billion doses by 2021 and expanding the range of vaccines available to us to constitute a portfolio of vaccines suitable for all situations and all contexts,” said Dr. Seth Berkley. executive director of the Vaccine Alliance (Gavi), which is a co-pilot with the World Health Organization (WHO) and the Coalition for Innovations in Epidemic Preparedness (Cepi), the Covax device.

• Promising results … but only with the original strain

In June, the pharmaceutical giant presented the results of clinical trials in some 30,000 people in the United States and Mexico, which showed an efficacy of 90.4% against the disease and 100% against severe to moderate cases. However, the study did not focus on the Delta variant, which was not yet widely used at the time. As for the Omicron variant, which has appeared in recent weeks, it has obviously not been discussed.

Nuvaxovid is given as two injections, usually into the muscle of the upper arm, 3 weeks apart. The side effects seen with serum in the studies were generally mild or moderate and resolved within a few days of vaccination.

• A more difficult adaptation to the variants.

Unlike the RNA vaccines, the Novavax vaccine will be more difficult to adapt to the variants. “Recombinant protein vaccines take longer to adapt to variants because the mutated protein must be recultured in vitro. In comparison, RNA vaccines simply rewrite the new mutated genetic code, which takes only a few weeks, ”explained Sandrine Sarrazin, an immunologist at the Marseille-Luminy Immunology Center in La Croix, a few months ago.