A study comparing individual immune responses to two major COVID-19 vaccines has shown that Moderna’s created more than double the antibodies than that of Pfizer and BioNTech.
The study involving 2,499 Belgian health-care workers who were vaccinated with two doses of either company’s vaccine was published on Monday in the Journal of the American Medical Association.
The research showed that previously infected participants had higher antibody levels than those who had not been infected, but Moderna’s
vaccine came out ahead for both groups. For those without previous infections, the antibody levels were 2881 units per milliliter among the Moderna candidates and 1108 for those who had the Pfizer
The study suggested a couple of reasons for the antibody level differences between vaccines, including a longer interval between shots for Moderna’s vaccine — 4 weeks — compared to Pfizer’s 3 weeks. As well, the researchers said the Moderna shot had a higher concentration of the key active ingredient used in both vaccines.
Antibody levels were also negatively correlated with age among previously uninfected participants, with highest levels found among those under 35, the study showed.