A box of the Novavax Covid-19 vaccine arranged at a pharmacy in Schwenksville, Pennsylvania, on Monday August 1, 2022.
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Biotechnology company Novavax announced on Friday that its Covid-19 vaccine has been approved by the U.S. Food and Drug Administration for emergency use for youth between the ages of 12 and 17.
In July, Novavax’s two-dose Covid-19 vaccine for adults ages 18 and older received its emergency use approval from the FDA.
Having more vaccine options for adults and children will “hopefully help increase vaccination rates, especially as we prepare for sustained waves of Covid-19 as fall and back-to-school season begin,” said Stanley C. Erck, President and CEO by Novavax, said in a statement.
Novavax was one of the original participants in the US government’s race to develop a Covid vaccine in 2020, receiving $1.8 billion in taxpayer dollars from Operation Warp Speed. However, the small Maryland biotech struggled to ramp up production quickly, and its clinical trial data was read much later than its competitors Pfizer or Moderna.
dr Peter Marks, a senior FDA official, said Novavax’s vaccine would appeal to potentially unvaccinated individuals who would prefer a syringe not based on the messenger RNA technology used by Pfizer and Moderna.
How Novavax is different
The Novavax vaccine is based on a more conventional protein technology that has been used in hepatitis B and HPV vaccines for decades, 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 the spike protein. The immune system responds to these copies of the spike, which primes the human body to attack the actual virus.
Novavax makes copies of the virus spike outside of human cells. The genetic code for the spike is put into an insect virus that infects moth cells that produce copies that are then purified and extracted during the manufacturing process. The finished Spike copies are injected into the human body and trigger an immune response against Covid.
The Novavax vaccine also uses an additional ingredient called an adjuvant, extracted and purified from the bark of a tree in South America, to induce a broader immune response. The injections consist of 5 micrograms of the spike copy and 50 micrograms of the adjuvant.
effectiveness and safety
Two doses of the Novavax vaccine were 90% effective in preventing disease from Covid and 100% effective in preventing major disease, according to clinical trial data from the United States and Mexico. However, the study was conducted from December 2020 to September 2021, months before the Omicron variant became dominant.
Novavax did not present data on the effectiveness of the shot against the variant at the FDA committee meeting in June. However, the vaccine will likely be less effective against Omicron than the Pfizer and Moderna vaccines. Omicron is so different from the original Covid strain that the antibodies produced by the vaccines have trouble recognizing and attacking the variant.
Novavax released data in December showing that a third injection boosted the immune response to levels comparable to the first two doses, which showed 90 percent efficacy against disease. The company plans to seek FDA approval for a third dose of its vaccine.
FDA approval of Novavax’s vaccines comes as the US prepares to update Covid vaccines to target the Omicron BA.4 and BA.5 variants to increase protection against the virus. Novavax’s vaccine, like all other vaccines, is based on the original version of the virus that first emerged in Wuhan, China. The effectiveness of Covid vaccines against mild illness has declined significantly as the virus has evolved, although they still generally protect against serious illness.
Novavax presented data at an FDA committee meeting in late June showing that a third dose of its vaccine elicited a strong immune response against Omicron and its subvariants. The committee members were impressed by the company’s data on omicron.
The Novavax vaccine also appears to carry a risk of heart inflammation in younger men known as myocarditis and pericarditis, similar to the Pfizer and Moderna vaccines. Myocarditis is inflammation of the heart muscle and pericarditis is inflammation of the outer lining of the heart.
FDA officials have reported four cases of myocarditis and pericarditis from the Novavax clinical trial in young men ages 16 to 28. People who develop heart inflammation as a side effect of Covid vaccines are usually hospitalized for several days as a precaution, but then recover.
The FDA has issued a factsheet for healthcare providers warning that clinical trial data suggest there is an increased risk of myocarditis with the Novavax vaccine. People who experience chest pain, shortness of breath, and a feeling of a fluttering or pounding heart should see a doctor right away, according to the FDA.
In the case of the mRNA shots, the CDC has found that the risk of myocarditis from Covid infection is higher than from vaccination. Myocarditis is usually caused by viral infections.