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

The fourth Covid shot to get emergency approval in the US has been authorized by the Food and Drug Administration.

After an all-day public meeting in which they weighed data on the vaccine's safety and its effectiveness from Covid, the FDA decided to approve Novavax's shot.

The CDC needs to sign off on the vaccine before it can be given to patients. Changes to the company's manufacturing process caused the FDA to delay approval of the vaccine.

One of the original participants in the US government's race to develop a Covid vaccine in 2020 was Novavax. The small Maryland company struggled to get manufacturing in place and read out its clinical trial data much later than other companies.

The FDA authorized Novavax's shots at a time when more than 75% of adults over the age of 18 already have their vaccinations. 27 million adults have not received a vaccine yet. According to Dr. Peter Marks, a senior FDA official, Novavax's vaccine could appeal to unvaccinated people who prefer a shot that is not based on messenger RNA technology.

The Novavax shot and Pfizer and Moderna are the first FDA approved vaccines to use a type of messenger riboflavin, also known as messenger riboflavin.

Moderna and Pfizer use a molecule called messenger RNA, or mRNA, to tell human cells to make a copy of a virus. The human body is trained to attack the actual viruses by the immune system.

The virus spikes outside human cells. During the manufacturing process, the genetic code for the spike is put into an insect virus that attacks moth cells, which produce copies of the genetic code. The human body has an immune response to Covid.

The bark of a tree in South America is used as an ingredient in the vaccine. The shots contain 5 and 50 micrograms of the same substance.

According to data from the U.S. and Mexico, the Novavax vaccine was effective at preventing illness from Covid across the board and at preventing severe illness. The trial took place from December 2020 to September 2021.

Data on the shot's effectiveness against the variant was not presented at the FDA committee meeting in June. The vaccine will likely have less effectiveness against omicron than Pfizer and Moderna did. Omicron is so different from the original strain of Covid that the vaccines can't recognize it.

In December, Novavax published data showing that a third shot boosted the immune response to levels similar to the first two shots. The FDA will be asked to approve a third dose of the vaccine.

As the U.S. prepares to update Covid shots to target the omicron BA.4 and BA.5 variant, the FDA has authorized Novavax's vaccine. The original version of the virus that first appeared in China is the basis of Novavax's vaccine. The effectiveness of Covid vaccines against mild illness has fallen as the virus has evolved.

At an FDA committee meeting in June, Novavax showed that a third dose of its vaccine produced a strong immune response against omicron. The committee was impressed by the data the company provided.

Myocarditis and pericarditis are similar to Pfizer and Moderna's shots and appear to be caused by the Novavax vaccine. Myocarditis and pericarditis are inflammations of the heart muscle.

Four cases of myocarditis and pericarditis were flagged by the FDA. People who develop heart inflammation as a side effect of Covid vaccines are usually hospitalized for a few days as a precautionary measure, but then recover.

There is a risk of myocarditis with the Novavax vaccine according to the FDA. According to the FDA, people who experience chest pain, shortness of breath, and feeling of a fluttering or pounding heart should immediately seek medical attention.

The risk of myocarditis is higher when the vaccine is used than when the shot is taken. The most common causes of myocarditis are viral infections.