The U.S. Centers for Disease Control and Prevention has recommended the use of Johnson & Johnson's single-dose coronavirus vaccine.
A 12-member panel recommended its use for people 18 years and older.
The endorsement will pave the way for the distribution and administration of the vaccine - expected to start this week. The Food and Drug Administration has already approved its emergency use.
"This vaccine is also another important tool in our toolbox to equitably vaccinate as many people as possible, as quickly as possible," centers director Rochelle Walensky said in a statement.
Johnson & Johnson's vaccine is the first single-dose vaccine authorized for distribution and use in the country. Unlike multidose vaccines offered by companies such as Pfizer and Moderna, Johnson & Johnson's treatment is easier to store and transport. The vaccine will be especially useful in rural communities and remote areas.
According to the administration, the vaccine has been proven to be 85% effective in preventing severe and critical COVID-19 symptoms and 66% effective in preventing moderate symptoms. The treatment's efficacy is lower than Pfizer and Moderna's vaccines at 95% and 94% effective, respectively.
The country's top infectious disease expert Anthony Fauci said the public shouldn't focus on the efficacy of the vaccines but be grateful that the U.S. now has three effective treatments.
"I think we need to pull away from this comparing and parsing of numbers until you compare them head-to-head. Just be really grateful that we have three vaccines," Fauci said.
Administration officials will be distributing up to 4 million doses of Johnson & Johnson's vaccine this week. Around 2 million doses will be given to states, while another 2 million doses will be distributed to community health centers and accredited pharmacies. State officials have been instructed to distribute all three vaccines evenly. Federal health officials said there should be enough doses to inoculate the populace through June.
