A box of the Novavax Covid-19 vaccine is lined up at a pharmacy in Schwenksville, Pennsylvania, U.S., Monday, Aug. 1, 2022.
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Biotech company Novavax announced Friday that its Covid-19 vaccine has been approved for emergency use by the US Food and Drug Administration for adolescents between the ages of 12 and 17.
In July, Novavax’s two-dose Covid-19 vaccine for adults 18 and older received emergency approval from the FDA.
Having more vaccine options for adults and children “will hopefully help increase vaccination rates, especially as we prepare for continued spikes in Covid-19 as fall and the back-to-school season begin,” Stanley S. Erk , president and CEO of Novavax, said in a statement.
Novavax was one of the early entrants in the US government’s 2020 race to develop a Covid vaccine, receiving $1.8 billion in taxpayer funding from Operation Warp Speed. However, the small Maryland biotech company struggled to get into production quickly, and data from its clinical trials was read much later than rivals Pfizer or Moderna.
Dr. Peter Marks, a senior FDA official, said Novavax’s vaccine would potentially appeal to unvaccinated people who would prefer an injection that is not based on the messenger RNA technology used by Pfizer and Moderna.
How Novavax is different
The Novavax injection is based on a more conventional protein technology used for decades in hepatitis B and HPV vaccines, while Pfizer and Moderna are the first FDA-approved vaccines to use mRNA.
The Pfizer and Moderna vaccines use mRNA, a molecule encoded with genetic instructions, to tell human cells to make copies of a viral particle called a spike protein. The immune system reacts to these copies of the spike, which prepares the human body to attack the actual virus.
Novavax makes copies of the virus outside of human cells. The genetic code for the spike is placed into an insect virus that infects moth cells that produce copies that are then purified and extracted during the production process. The finished spikes are injected into the human body, triggering an immune response against Covid.
The Novavax vaccine also uses an additional ingredient called an adjuvant that is extracted and purified from the bark of a tree in South America to induce a broader immune response. The injections consisted of 5 micrograms of spiked lance and 50 micrograms of adjuvant.
Efficiency and safety
Two doses of the Novavax vaccine were 90% effective in preventing Covid disease everywhere and 100% effective in preventing severe disease, according to data from clinical trials in the US and Mexico. However, the trial was conducted from December 2020 to September 2021, months before the omicron variant became dominant.
Novavax did not present any data on the injection’s effectiveness against the variant at an FDA committee meeting in June. However, the vaccine is likely to be less effective against omicron, as is the case with the Pfizer and Moderna vaccines. Omicron is so different from the original strain of Covid that the antibodies produced by the vaccines have trouble recognizing and attacking the variant.
Novavax published data in December showing that a third injection boosted the immune response to levels comparable to the first two doses, which were 90 percent effective against disease. The company plans to ask the FDA to authorize a third dose of its vaccine.
The FDA approval of Novavax’s vaccines comes as the US prepares to update its Covid vaccines to target the omicron BA.4 and BA.5 variants to increase protection against the virus. The Novavax vaccine, like all other vaccines, is based on the original version of the virus that first appeared in Wuhan, China. The effectiveness of Covid vaccines against mild disease has declined significantly as the virus has evolved, although they still generally protect against severe disease.
Novavax presented data at an FDA panel meeting in late June demonstrating that a third dose of its vaccine elicited a strong immune response against omicron and its subvariants. Committee members were impressed with the company’s omicron data.
The Novavax vaccine appears to carry a risk of heart inflammation in younger men known as myocarditis and pericarditis, similar to the Pfizer and Moderna injections. Myocarditis is an inflammation of the heart muscle and pericarditis is an inflammation of the outer lining of the heart.
FDA officials noted four cases of myocarditis and pericarditis from a clinical trial of Novavax in young men ages 16 to 28. People who develop heart inflammation as a side effect of Covid vaccines are usually hospitalized for a few days as a precaution, but then recover.
The FDA has issued an information sheet for healthcare providers warning that clinical trial data show an increased risk of myocarditis with the Novavax vaccine. People who experience chest pain, shortness of breath, and a fluttering or pounding heart should seek immediate medical attention, according to the FDA.
In the case of the mRNA shots, the CDC found that the risk of myocarditis was higher from Covid infection than vaccination. Myocarditis is usually caused by viral infections.