Americans now have a fourth COVID shot option as the Centers for Disease Control and Prevention authorized a new vaccine from Novavax on Tuesday.

The shot is different from the current COVID vaccine offerings as it is a protein-based shot that fights against the virus in a more traditional form of a vaccine.

The move to get the vaccine signed off by the CDC is a hopeful effort from the agency to get the millions of Americans who are hesitant to get inoculated with the shot.

“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,” Dr. Rochelle Walensky, director of the CDC, said in a statement.

Currently, 67.1% of Americans are fully vaccinated against COVID-19, with 48.1% receiving at least one booster dose, the CDC said.

Unlike the Pfizer, Moderna, and Johnson & Johnson shots, the Novavax vaccine uses a spike protein to train the body to produce antibodies that are immune to the virus. It also uses adjuvant, an ingredient taken from the bark of a South American tree, which is designed to increase immune response.

With the Pfizer and Moderna vaccines, the body is taught to make copies of the spike protein to fight the virus using mRNA technology, while the Johnson & Johnson vaccine uses a cold virus to combat COVID.

The technology behind the Novavax vaccine has been in existence for more than 30 years and is used in other shots that prevent diseases such as the flu, whooping cough, and hepatitis B. The shot has been recommended by the CDC for those aged 18 and older.

The effectiveness of the Novavax vaccine, which is given in two doses three weeks apart, is about 90% in the prevention of illness and 100% effective at preventing disease, with mild reactions that include arm pain and fatigue. It is unclear how effective the Novavax shot would be against new variants such as Omicron’s BA.5 and BA.2.75.

But like the Pfizer and Moderna vaccines, there is a rare risk of heart inflammation, particularly in teenage boys and young men. However, the CDC has said the risk of contracting COVID-19 is greater than myocarditis, as reported by CNBC.

The government has purchased 3.2 million doses of the Novavax vaccine, which is expected to roll out in the next few weeks. The Novavax vaccine is also administered in other countries such as Canada, Australia, South Korea, as well as in Europe, with the company saying it expects to request authorization for a booster shot of the vaccine from the Food and Drug Administration.

Vials labelled "VACCINE Coronavirus COVID-19" and a syringe are seen in front of a displayed Novavax logo in this illustration taken December 11, 2021.
Vials labelled "VACCINE Coronavirus COVID-19" and a syringe are seen in front of a displayed Novavax logo in this illustration taken December 11, 2021. Reuters / DADO RUVIC