ALBANY, N.Y. (NEWS10)- The Janssen (Johnson and Johnson) COVID-19 vaccine is getting people’s attention for being administered in one shot as opposed to Pfizer and Moderna’s two-shot doses. However, that’s not the only difference.

Janssen Biotech Inc.’s version, approved for emergency use by the U.S. Food and Drug Administration (FDA) on February 27, uses a different delivery system than Pfizer’s or Moderna. Its efficacy is also lower than the two previously approved vaccines.

All vaccines work by teaching the body to form a response to the infection, said Associate Professor of Microbiology at Albany College of Pharmacy and Health Sciences (ACPHS), Dr. Eric Yager in a previous interview with NEWS10.

The Pfizer and Moderna COVID-19 vaccines were both manufactured using Messenger RNA (mRNA) technology. mRNA is delivered into the body with a mixture of lipids (fat droplets), salts, and sugars which help it get absorbed into cells, according to FDA briefing documents.

The Janssen COVID-19 vaccine uses an adenovirus (adenovirus type 26) to deliver the genetic material into cells. The virus is modified to prevent it from replicating in the body and cause illness. It does activate the immune system to produce a defense response against COVID-19, FDA briefing documents said.

Most commonly reported side effects

Injection site reaction- 84.1%Injection site pain- 91.6%Fatigue- 38.2%
Fatigue- 62.9%Fatigue- 68.5%Headache- 39%
Headache- 55.1%Headache- 63%Myalgia (muscle pain)- 33.2%
Muscle pain- 38.3%Muscle pain- 59.6%
Chills- 31.9%Joint pain- 44.8%
Joint pain- 23.6%Chills 43.4%
Fever- 14.2

When to call the doctor after getting vaccinated

  • If redness or tenderness at the injection site gets worse after 24 hours
  • If side effects don’t go away after a couple of days
  • If you’re experiencing any side effects that are worrisome

*Source: Centers for Disease Control and Prevention

Pfizer’s vaccine is 95% effective and Moderna’s is 94.5% effective after the second dose. Because it’s one dose, the efficacy for Janssen’s vaccine was scored differently. It is approximately 77% effective in the first 14 days after the shot and 85% effective at least 28 days post shot.

The Janssen vaccine can be stored at normal temperatures between 36-46 degrees Fahrenheit. Pfizer and Moderna vaccines both have to be stored at seriously low temperatures. Pfizer between -112 to -76 degrees Fahrenheit and Moderna between -13 to -5 degrees Fahrenheit.

As with Pfizer and Moderna’s COVID-19 vaccine, Janssens is approved for adults only. Both Moderna and Janssen’s versions are approved for use in people 18 years and older.

Pfizer’s is approved for use in people 16 years and older. The company has asked the FDA to approve its COVID-19 vaccine in children ages 12-15 after a clinical trial showed the efficacy rate to be 100% in this age group.