Drugmaker Moderna has asked the Food and Drug Administration to authorise the fourth shot of its Covid-19 vaccine as a booster dose for all adults.
Modern said the request to the US FDA would, "allow for the fourth dose of our #COVID19 vaccine in adults 18 years of age and older who have received an initial booster" of any approved Covid jab".
The request to include adults over 18 years of age was made to provide flexibility for the US CDC and healthcare providers to determine the appropriate use of an additional booster dose of mRNA-1273, including for those at higher risk of Covid-19, the company added.
Moderna's request comes days after Pfizer-BioNTech, makers of the other Covid mRNA vaccine, also requested emergency approval for a second booster shot, but their request was limited to adults aged 65 and older.
The request was based partly on recent data from the United States and Israel about how well the Moderna shot protected against the Omicron variant of the coronavirus, according to the AFP news agency.
Pfizer also based its request off two Israeli studies, which it said in a press statement show "an additional mRNA booster increases immunogenicity and lowers rates of confirmed infections and severe illness."
The first Israeli study showed that "rates of confirmed infections were two times lower and rates of severe illness were 4 times lower among individuals who received an additional booster dose," compared to those who only had one.
The analysis was limited to people age 60 and older who received their second booster four months after their first.
The second analysis on Israeli health care workers 18 and up showed that antibody levels in those who received a second booster were significantly higher than those who did not.
Since the initial regimen of both the Pfizer-BioNTech and Moderna vaccines is two doses, a second booster would be most individuals' fourth jab.
(With AFP inputs)
