As of now, three COVID-19 vaccines are available in the U.S., including those developed by Moderna, Pfizer-BioNTech and Johnson & Johnson. According to the Centers for Disease Control and Prevention (CDC), the Moderna shots, given 28 days apart, can only be given to people 18 years and older currently. Side effects may include pain, redness and swelling at the injection site, chills, muscle pain, fever and nausea. Based on clinical trials by the Food and Drug Administration, the Moderna vaccine was proven to be 94.1 percent effective after two doses at preventing symptomatic disease in those who were not previously infected with COVID-19.
The Pfizer shots, given 21 days apart, can be given to people ages 16 years and older. “Pfizer has also recently completed a study in 12-16 year olds, which has shown promise,” said Dr. Mimi Vanoyan with Atlanta Obstetrics and Gynecology Associates. The same side effects of Moderna also apply to the Pfizer vaccine. As reported in The Washington Post, Pfizer and Moderna were found to reduce the risk of infection by 80% just after one shot. With the second dose, Pfizer’s efficacy rate jumps to 95%.
Despite its initial approval, the Johnson & Johnson vaccine use has been asked to be suspended by federal health officials until they can investigate the six extremely rare but troubling cases of blood clots, according to the New York Times. Blood clotting seems to affect one out of every million people injected with the vaccine, and it is not yet clear if the vaccine is the cause. According to NPR, the CDC has recommended a pause in the use of the Johnson & Johnson vaccine while it is in review. But, it only requires one shot and is available to those 18 years and older. It may also produce the same side effects as Moderna and Pfizer. The vaccine’s efficacy rate is 72% overall and 86% effective at preventing serious illness.
Storage plays a large role when differentiating between the three vaccines. According to Yale Medicine, Pfizer has strict requirements involving how the vaccine is stored. The vaccine needs to be shipped in ultra-cold temperature controlled units (-94 degrees Fahrenheit). Pfizer submitted new data to the FDA in mid-February, revealing stability of the vaccine at temperatures more commonly found in pharmaceutical refrigerators and freezers, allowing for easier distribution. Pfizer is awaiting FDA approval on revised storage requirements. The Moderna vaccine, authorized for emergency use in the U.S., can be shipped and kept in long term storage in standard freezer temperatures.
Both the Moderna and Pfizer vaccines have a new and similar approach to preventing COVID-19. They are messenger RNA vaccines. Unlike traditional vaccines that deposit a weakened or inactivated disease germ into the body, the Pfizer and Moderna vaccines insert a lipid wrapped mRNA into human cells. This gives the cells instructions for making spike proteins that alert the immune system to recognize the virus and stimulate an immune response.
The Johnson & Johnson Vaccine, as reported in Yale Medicine, is much easier to store, as it can be held at standard refrigerator temperatures. In November, Johnson & Johnson announced that it would launch a second clinical trial to study two doses, two months apart, comparing the protection rates. “It is called a viral vector vaccine,” said Dr. Vanoyan. “Johnson & Johnson uses a modified version of a different virus for our body to build immunity.”