CDC signs off on Novavax COVID-19 vaccine for adults

(CNN) -- Dr. Rochelle Walensky, director of the US Centers for Disease Control and Prevention, said Tuesday that she has endorsed the recommendation of the agency's vaccine advisers to use the Novavax Covid-19 vaccine as a two-dose primary series in adults.

It's the fourth coronavirus vaccine available in the United States, and it uses a different type of vaccine technology than the other shots.

"Novavax's COVID-19 vaccine, which will be available in the coming weeks, is an important tool in the pandemic and provides a more familiar type of COVID-19 vaccine technology for adults," the CDC said in a news release. "Having multiple types of vaccines offers more options and flexibility for the public, jurisdictions, and vaccine providers."

Earlier in the day, the CDC's Advisory Committee on Immunization Practices voted 12-0 to recommend the vaccine. Walensky's signoff was the final step in the process before shots can be given.

In a statement, President Biden applauded the move, calling it "another step forward in our nation's fight against the virus."

"The science and data are clear: vaccines continue to protect people from serious illness, hospitalizations, and death -- and with BA.5 increasing infections, it is essential that people get themselves and their kids vaccinated and stay up to date on their COVID-19 vaccinations," Biden said, encouraging Americans to get vaccinated or boosted if eligible.

"While we know COVID-19 isn't over, we can manage this moment and continue to minimize COVID-19's impact on our daily lives."

The Gaithersburg-based company's vaccine is made using small laboratory-built pieces of the coronavirus to stimulate immunity. Overall, the vaccine relies on recombinant nanoparticle technology and Novavax's adjuvant, called Matrix-M, to stimulate an immune response and high levels of neutralizing antibodies.

This protein-based approach is a more traditional one for vaccine development than the mRNA vaccines from Pfizer/BioNTech and Moderna.

Protein-based vaccines like Novavax's work by getting the body's immune system to recognize little modified pieces of the virus it's targeting. In this case, that means pieces of the coronavirus spike protein.

When the genetic sequence for the virus that causes Covid-19 was published, scientists around the world quickly identified it as a coronavirus because of the "spike proteins" on its surface. These spikes form large protrusions, giving coronaviruses the appearance of wearing crowns, and "corona" is the Latin word for "crown."

Novavax scientists identified the gene for the spike protein and created a modified version of that gene. The researchers cloned the genes into a baculovirus that infects insects. They then infected moth cells -- specifically, cells from the fall armyworm -- prompting them to produce the coronavirus spike protein. These virus-like nanoparticles were harvested to make Novavax's vaccine.

"If you have been waiting for a COVID-19 vaccine built on a different technology than those previously available, now is the time to join the millions of Americans who have been vaccinated," Walensky said in the news release. "With COVID-19 cases on the rise again across parts of the country, vaccination is critical to help protect against the complications of severe COVID-19 disease."

As of Monday, about two-thirds of the US population, 67%, is fully vaccinated with at least their initial series of Covid-19 vaccine. But less than a third, 32%, of the population has received a booster dose of vaccine.