People who received the Moderna COVID-19 vaccine reported more side effects than those who got the Pfizer/BioNTech shot, according to a recent study by the Centers for Disease Control and Prevention (CDC).

Of those who received one dose of the messenger RNA vaccine, 74 percent of Moderna recipients reported injection site reactions of pain, swelling, redness, and itching, as opposed to 65.4 percent of the Pfizer/BioNTech recipients.

Furthermore, 52 percent of those who received the Moderna vaccine said they had a generalized reaction like fatigue, headache, and body pain, compared to 48 percent of recipients who had the Pfizer/BioNTech vaccine.

Both local and systemic reactions occurred more frequently after the second dose for both vaccines: Moderna recipients reported 82 percent and 74 percent, while Pfizer/BioNTech recipients reported 69 percent and 64.2 percent, respectively.

Two days after the publication of the CDC study, the NIAID announced that it was funding a Phase 2 trial to examine whether people with a history of allergic reactions or who have a mast cell disorder are at increased risk of an immediate, systemic allergic reaction to the Moderna or Pfizer/BioNTech COVID-19 vaccines.

“The public understandably has been concerned about reports of rare, severe allergic reactions to the Moderna and Pfizer-BioNTech COVID-19 vaccines,” Fauci said in a statement.