Moderna vaccine could create twice as many COVID antibodies as Pfizer vaccine, study says

Moderna’s COVID-19 vaccine created more than twice the antibodies than the Pfizer COVID-19 vaccine, according to a study comparing the immune responses to the inoculations.

The study of nearly 2,500 workers at a major Belgium hospital system discovered that the average antibody levels of those who took a full course of the Moderna vaccine was 3836 U/mL while those who took a full course of the Pfizer vaccine had antibody levels of 1444 U/mL.

Both vaccines have been shown to be highly effective against serious illness and death.

The study results, published Monday in a letter to the Journal of the American Medical Association, proposed that the differences in immune response might be explained by two things:

  • The Moderna vaccine contains more of an active ingredient than the Pfizer vaccine (100 micrograms vs. 30 micrograms).
  • There is a longer amount of time between the doses of the Moderna vaccine than the Pfizer vaccine. Moderna’s two shots are spread out by four weeks while Pfizer’s shots are spread out by three weeks.

Related stories about COVID-19:

When will the Moderna vaccine get FDA approval?

What does FDA approval mean for the COVID vaccine?

When will the Johnson & Johnson vaccine get FDA approval?

Is it safe to get a flu shot and COVID vaccine at the same time?

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Katherine Rodriguez can be reached at [email protected]. Have a tip? Tell us at