Johnson & Johnson has begun shipping out its newly approved COVID-19 vaccine and intends to ensure that the American public is able to get its hands on its shot within the next two days.

The Johnson & Johnson vaccine was approved by the FDA on Saturday and has proven to be the easiest of all three approved candidates to store. Unlike the vaccines provided by Pfizer-BioNTech and Moderna, it only requires individuals to take one shot as opposed to two shots.

While its competitors have an efficacy of over 90%, the Johnson & Johnson jab is only 66% effective overall against moderate to severe COVID-19 infections. Studies indicate that its effectiveness appeared to vary depending on one’s geographic locations, Stat News reported.

However, the vaccine was also found to have an 85% effectiveness against severe cases. Under clinical trials, officials further determined that individuals who received the Johnson & Johnson shot were not hospitalized and had not died from COVID-19 in the 28 days it took for them to develop an immunity against SARS-CoV-2, the deadly virus that causes COVID-19.

Trials for the Johnson & Johnson candidate were carried out between October 2020 and January 2021, a time when several variants of the COVID-19 strain began to emerge and prove much more contagious. Officials have underscored that the new variants are not believed to be deadlier.

Johnson & Johnson is next expected to undertake clinical trials to study the vaccine’s effect on pregnant women and children over the age of 12. The company will also take steps to examine the impact of a possible second dose.

The latest figures by the US Centers of Disease Control and Prevention indicate 96.4 million vaccines have been delivered, but that only 76.8 million doses have actually been administered. Some 25.4 million Americans have been fully vaccinated against the novel coronavirus.