A study showed that the Moderna COVID-19 vaccine, which the company says was recently demonstrated to have 94 percent efficacy, causes the human immune system to produce potent antibodies that endure for at least three months.

Researchers at the National Institute for Allergies and Infectious Diseases (NIAID), which co-developed the drug, studied the immune response of 34 adult participants, young and old, from the first stage of a clinical trial.

Writing in the New England Journal of Medicine, they said that the antibodies, which stop the SARS-CoV-2 virus from invading human cells, “declined slightly over time, as expected, but they remained elevated in all participants 3 months after the booster vaccination.”

Even though the number of antibodies in the study subjects faded over time, it is not necessarily a cause for concern.

NIAID director Anthony Fauci and other experts have said it is very likely that the immune system will remember the virus if re-exposed later on, and then produce new antibodies.