WASHINGTON: An American biotech company, Moderna, announced on Monday that initial human trials of its coronavirus vaccine produced Covid-19 antibodies in all 45 participants.

“With today’s positive interim Phase 1 data and the positive data in the mouse challenge model, the Moderna team continues to focus on moving as fast as safely possible to start our pivotal Phase 3 study in July and, if successful, file a license application,” said Moderna’s Chief Executive Officer Stéphane Bancel.

“We are investing to scale up manufacturing so we can maximize the number of doses we can produce to help protect as many people as we can from SARS-CoV-2.”

The announced sent the company’s shares surging more than 39 per cent in premarket trading. Moderna is one of seven companies conducting human trials and the first in the United States to start doing so, on March 16.

But The New York Times, while reviewing the announcement, warned that “limited data from the early phase leaves much uncertainty around the vaccine’s potential success.” In a statement issued by its headquarters in Cambridge, Massachusetts, the company said each participant received a 25 microgram, 100 mcg or 250 mcg dose, with 15 people in each dose group. All received two doses of the potential vaccine via intramuscular injection in the upper arm approximately 28 days apart.

At day 43, following the second dose, levels of binding antibodies in the 25-mcg cohort were at the levels generally seen in blood samples from people who recovered from the disease. Antibodies in the 100 mcg had antibodies that “significantly exceeded levels” in recovered patients. Data on a second dose was not available for the 250-mcg group.

The vaccine — mRNA-1273 — “was generally safe and well tolerated” and “provided full protection against viral replication in the lungs,” the company said. The levels of antibodies in the mice, which was sufficient to block the virus, was also the same as in the humans dosed with the vaccine.

Anticipated dose for Phase 3 study, expected to start in July, is between 25 µg and 100 µg.

The company said that three patients at the highest dose level experienced some discomfort, including fever, after receiving their second dose of the vaccine. That dose level will not be given in the Phase 2 trial. One patient at a lower dose level experienced redness at the injection site.

Antibodies collected from the volunteers were tested in human cells in the lab and were able to stop the virus from replicating. The announcement represents the first positive data on human trials of a Covid-19 vaccine and raised hopes for finding a vaccine to prevent a second wave of the pandemic, which has already killed more than 300,000 people across the globe. The US National Institute of Allergy and Infectious Diseases (NIAID) worked with Moderna while the US Department of Health provided funds for the project.

Published in Dawn, May 19th, 2020