A box of the Novavax Covid-19 vaccine is held at a pharmacy in Schwenksville, Pennsylvania, US, Monday, August 1, 2022.
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The biotechnology company Novavax announced on Friday that its Covid-19 vaccine has been authorized for emergency use by the US Food and Drug Administration for adolescents between the ages of 1[ads1]2 and 17.
In July, Novavax received its emergency approval from the FDA for its two-dose Covid-19 vaccine for adults aged 18 and over.
Having more vaccine options for adults and children will “hopefully help increase vaccination rates, especially as we prepare for ongoing waves of Covid-19 with the start of fall and the back-to-school season,” Stanley C. Erck, president and CEO of Novavax, said in a statement.
Novavax was one of the original participants 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 biotechnology company in Maryland struggled to quickly get production in place and data from clinical trials was read out much later than competitors Pfizer or Moderna.
Dr. Peter Marks, a senior FDA official, has said that Novavax’s vaccine would potentially appeal to unvaccinated people who would prefer a shot that is not based on the messenger RNA technology used by Pfizer and Moderna.
How Novavax is different
The Novavax shot is based on 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.
Pfizer and Moderna’s vaccines use mRNA, a molecule encoded with genetic instructions, to tell human cells to produce copies of a virus particle called the spike protein. The immune system reacts to these copies of the spike, which prepares the human body to attack the virus itself.
Novavax makes copies of the virus outside of human cells. The genetic code for the spike is inserted into an insect virus that infects moth cells, which produce copies that are then purified and extracted during the production process. The finished spike copies are injected into the human body, and induce an immune response against Covid.
The Novavax vaccine also uses an additional ingredient called an adjuvant, which is 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.
Efficiency and safety
Two doses of the Novavax vaccine were 90% effective in preventing illness from Covid across the board and 100% effective in preventing severe illness, according to data from clinical trials from 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 shot’s effectiveness against the variant at the FDA committee meeting in June. However, the vaccine is likely to be less effective against omicron, as is the case with Pfizer and Moderna’s shots. 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 shot boosted the immune response to levels comparable to the first two doses, which were 90% effective against disease. The company plans to ask the FDA to approve a third dose of the vaccine.
FDA approval of Novavax’s vaccines comes as the US prepares to update the Covid shots to target the omicron BA.4 and BA.5 variants to boost protection against the virus. Novavax’s vaccine, like all the other shots, 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 committee meeting in late June demonstrating that a third dose of the vaccine produced 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 for younger men, known as myocarditis and pericarditis, similar to Pfizer and Moderna’s shots. Myocarditis is an inflammation of the heart muscle and pericarditis is inflammation of the heart’s outer lining.
FDA officials flagged four cases of myocarditis and pericarditis from Novavax’s 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 fact sheet for healthcare professionals warning that clinical trial data indicate an increased risk of myocarditis with the Novavax vaccine. People who experience chest pain, shortness of breath and feelings of a fluttering or pounding heart should seek immediate medical attention, according to the FDA.
As for the mRNA shots, the CDC has found that the risk of myocarditis is higher from Covid infection than vaccination. Myocarditis is usually caused by viral infections.