COVID19 vaccine by Moderna Inc. has been to produce more than double the antibodies of a similar shot by Pfizer Inc. and BioNTech SE. This was found in a study conducted on about 2,500 workers at a major Belgium hospital system.

It revealed that antibody levels among individuals who had not been infected with the virus before getting two doses of the Moderna vaccine averaged 2,881 units of antibodies per milliliter, compared with 1,108 units/mL in an equivalent group who got two jabs of the Pfizer shot.

The study was published yesterday on August 30 in a letter to the Journal of the American Medical Association.

Moderna’s vaccine was associated with a two-fold risk reduction against breakthrough SARS-CoV-2 infections compared to Pfizer’s in a review of people in the Mayo Clinic Health System in the US from January to July.

The results suggested that the difference might be explained by the higher amount of active ingredient in the Moderna vaccine (100 micrograms, versus 30 micrograms in Pfizer-BioNTech) and longer interval between doses of the Moderna vaccine (four weeks, versus three weeks for Pfizer-BioNTech).

Meanwhile, recent data confirm that the Pfizer-BioNTech and Moderna COVID19 vaccines reportedly carry a small risk of rare heart problems, most common in adolescent boys and young men. Still, the benefits of vaccination outweigh the risks, scientists said.

Moderna’s COVID19 vaccine won an emergency use approval from the Indian government in June.

Last week, India also approved clinical trials for its first homegrown mRNA-based COVID19 vaccine developed by Gennova Biopharmaceuticals Ltd. Gennova is among a few pharmaceutical firms globally, including Moderna Inc and Pfizer Inc, to use mRNA technology. These vaccines do not use a live virus to generate an immune response. They prompt the human body to make a protein that triggers one.

So far, India has administered 639 million doses. Of these, about 87 per cent doses were of Covishield and 12 per cent were of Covaxin.