According to a study, Covid-19 infected patients who were inoculated with a novel antibody had demonstrated fewer symptoms of the virus and were less likely to be severely infected than those who did not receive the antibody.

The study was published in The New England Journal of Medicine.

The study noted that the multisite, Phase II clinical trial tested three different doses of LY-CoV555, a monoclonal antibody derived from the blood of a recovered Covid-19 patient.

The preliminary findings of the ongoing trials indicated a reduced viral load in outpatients with mild to moderate cases of Covid-19 along with reduced rates of hospitalisation and emergency medical care. The patients were given the 2,800-milligram dosage of antibodies.

The study’s co-first author, Peter Chen, MD, professor of Medicine and director of the Division of Pulmonary and Critical Care Medicine at Cedars-Sinai, said the results are promising.

Chen said: “For me, the most significant finding was the reduction in hospitalizations. Monoclonal antibodies like this have the potential to reduce the severity of Covid-19 for many patients, allowing more people to recover at home.”

Monoclonal antibodies work by attaching themselves to a virus to prevent its multiplication. LY-CoV555 binds to a particular protein, called a spike protein, which SARS-CoV-2 needs in order to enter human cells and replicate.

By preventing the virus from replicating, the antibody slows down the viral process, allowing the patient’s own immune system time to kick into gear.

Chen added: “What we’re doing is preventing the virus from causing too much damage early on in the process. We’re buying the patients’ time so that their bodies can start developing their own immunity to fight the virus.”

For the experiment, patients who participated in the study were given intravenous doses of either 700, 2,800, or 7,000 milligrams of the antibody, or a placebo.

Investigators used a nasopharyngeal swab to test patients’ viral load before administering the antibody and again at several points after administering the drug.

Approximately, 300 patients received the treatment (100 patients per dosage level) and approximately 150 patients received the placebo.

The results revealed that of the three dosage levels, the 2,800-milligram dosage was shown to be effective in reducing viral load. By day 11, viral load was substantially diminished for most patients, including those in the placebo arm.

Reduction in hospitalisation

The study added that on day 29, hospitalisation rates were only 1.6 per cent in the antibody-treated group, compared with 6.3 per cent in the group that received the placebo.

Notably, the reduction in hospitalisations was seen even in high-risk categories: adults older than 65 and those with a high body mass index (greater than 35).

For high-risk patients, hospitalisation rates were 4.2 per cent in patients treated with the antibody, compared with 14.6 per cent in placebo-treated patients, the study noted.

“We know that Covid-19 is especially hard on the elderly, the obese, and people with certain pre-existing health conditions. Antibody treatments like this may have the most benefits for people in these higher-risk categories,” Chen added.