FDA Shortens Interval for Moderna COVID-19 Booster Based on Safety Data From Pfizer’s Booster Doses

A health worker checks a box of the Moderna COVID-19 vaccine donated by the United States, during a booster vaccination drive at the Zainoel Abidin hospital in Banda Aceh, Indonesia, on Aug. 9, 2021. Chaideer Mahyuddin/AFP via Getty Images

The Food and Drug Administration’s (FDA) decision to shorten the interval time for Moderna’s COVID-19 vaccine to five months was based on scientific evidence that included the safety data from Pfizer’s booster shots given in Israel, the health regulator wrote in its authorization letter to Moderna.

The health regulator announced Friday that it had amended its emergency use authorization for Moderna’s COVID-19 vaccine, shortening the six-month interval time between completing the two-dose series and the booster to five months. This change aligns with the FDA’s earlier revision for Pfizer’s COVID-19 vaccine.

The FDA argues that the change is necessary because of the “highly contagious Omicron variant, which spreads more rapidly” than the original virus and other variants so far.

The FDA claims to have reviewed various publications that weren’t cited in the letter along with data of Israel’s 4.1 million citizens who have received the Pfizer vaccine booster.

“For the Jan. 7, 2022, authorization revising the authorized dosing interval of the homologous booster dose to at least 5 months after completion of the primary series, the FDA reviewed: prepublications; accepted publications; published publications; and real world evidence on the safety of booster doses provided by the Israeli Ministry of Health, which includes data from approximately 4.1 million third (booster) doses of the Pfizer-BioNTech COVID-19 Vaccine given to individuals 16 years of age and older at least 5 months after the primary series, and which did not raise new safety concerns associated with the booster dose,” the FDA wrote (pdf).

The federal health regulator acknowledged that the overall composition of the two messenger RNA vaccines differed, but because “both are mRNA vaccines,” they “are relatively similar.”

“Acknowledging the differences, it is reasonable to make the inference that the safety data on the [five] month interval for booster doses obtained in the population in Israel can apply to the Moderna COVID-19 Vaccine,” the FDA said.

Revision to Moderna’s booster dose drew criticism from Dr. Vinay Prasad, a hematologist-oncologist and an associate professor of epidemiology at the University of California–San Francisco, who argued that the FDA’s decision was not based on scientific evidence and that “it is NOT REASONABLE to make a Moderna determination from Pfizer data.”

“FDA is not even trying anymore; The decision is based on PFIZER data not MODERNA data, which they acknowledge in today’s letter,” Prasad said in a tweet. “There is literally have [sic] NO EVIDENCE for boosting MODERNA at month 5.”

He also compared the doses of the two mRNA vaccines, saying “Moderna’s dose is 100, 100, and 50 for booster; Pfizer is 30, 30, 30,” adding that “Moderna has Way more myocarditis.”

According to the Centers for Disease and Prevention (CDC), “since April 2021, increased cases of myocarditis [heart inflammation] and pericarditis [inflammation of the tissue surrounding the heart] have been reported in the United States after mRNA COVID-19 vaccination (Pfizer-BioNTech and Moderna), particularly in adolescents and young adults.”

The increase in myocarditis and pericarditis after receiving an mRNA vaccine prompted the FDA to update its patient and provider fact sheets in June 2021, warning of the increased risk of the severe side effects following vaccination.

When asked about why the FDA based their decision on Pfizer’s safety data instead of Moderna’s vaccine booster data, a spokesperson from the FDA, in an email to The Epoch Times, provided a link to the authorization letter and said that a “memo outlining our decision should be posted in the very near future.”

The Epoch Times has reached out to Moderna for comment.