FDA approves Novavax Covid vaccine for adults

In this photo illustration, the Food and Drug Administration (FDA) and Novavax logos are visible behind the medical syringe and vials.

Pavel Gonchar | Light rocket | Getty Images

The Food and Drug Administration approved Novaxtwo-dose vaccine for adults aged 18 years and over, the fourth Covid shot to receive emergency US approval with pandemic began.

The FDA’s decision comes weeks after its committee of independent vaccine expertsHighly voted in favor of throwing Novavax in early June, after an all-day open meeting where they weighed in on the safety of the vaccine and its effectiveness in preventing Covid.

The Centers for Disease Control and Prevention still needs to sign the Novavax vaccine before pharmacies and other health care providers can start giving shots. FDA approval for the Novavax vaccine has been delayed by several weeks as the agency considered changes in the company’s production process.

Novavax was an early entrant in the US government’s 2020 Covid vaccine race, having received $1.8 billion in taxpayer funding through Operation Warp Speed. However, the small Maryland biotech company struggled to get production up and running quickly, and its clinical trial data came out much later than Pfizer or Moderna.

Novavax vaccines received FDA approval at a time when almost 77% of adults aged 18 years and over are already fully vaccinated. However, 27 million adults still have not received a single shot. Dr. Peter Marks, a senior FDA official, said the Novavax vaccine could potentially appeal to unvaccinated people who would prefer a vaccine not based on messenger RNA technology used by Pfizer and Moderna.

What makes Novavax different

Novavax is based on 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 force 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 real virus.

Novavax makes copies of the virus spike outside of human cells. The spike’s genetic code is inserted into an insect virus that infects the moth’s cells, which produce copies that are then purified and extracted during the manufacturing process. Ready-made spike copies are injected into the human body, causing 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. Injections consist of 5 µg spike copy and 50 µg adjuvant.

Efficacy and safety

Two doses of the Novavax vaccine were 90% effective in preventing Covid disease across the board and 100% effective in preventing severe disease, according to clinical trials conducted in the US and Mexico. However, the trial was conducted from December 2020 to September 2021, a few months before the omicron variant became dominant.

Novavax did not provide data on the effectiveness of the vaccine against this variant at the June FDA committee meeting. However, the vaccine is likely to be less effective against omicrons, 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 a hard time recognizing and attacking the variant.

In December, Novavax published data showing that the third injection boosted the immune response to a level comparable to the first two doses, which were 90 percent effective against the disease. The company plans to ask the FDA to approve a third dose of its vaccine.

FDA approval for Novavax vaccines comes as the US prepares to update its Covid shots to target omicron BA.4 and BA.5 variants to boost 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 illness has declined substantially as the virus has evolved, although they still generally protect against severe illness.

Novavax presented data on FDA committee meeting at the end of June demonstrating that the third dose of his vaccine elicited a strong immune response against Omicron and its sub-variants. Committee members were impressed with the company’s omicron data.

The Novavax vaccine also appears to carry a risk of heart inflammation in young men, known as myocarditis and pericarditis, similar to the Pfizer and Moderna vaccines. Myocarditis is an inflammation of the heart muscle, while pericarditis is an inflammation of the outer lining of the heart.

FDA officials noted four cases of myocarditis and pericarditis in Novavax clinical trials in young men aged 16 to 28 years. 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 a fact sheet to healthcare professionals warning that clinical trial data indicate an increased risk of myocarditis with the Novavax vaccine. According to the FDA, people who experience chest pain, shortness of breath, and a feeling of fluttering or palpitations should seek immediate medical attention.

in case of mRNA shotsThe CDC has found that the risk of myocarditis from Covid infection is higher than from vaccination. Myocarditis is usually caused by viral infections.

CNBC Health & Science

Read the latest CNBC Global Health Review: