Covid-19: Moderna soars 18% as vaccine gives promising early results

Moderna’s Covid-19 vaccine produced antibodies to the coronavirus in all patients tested in an initial safety trial, federal researchers said, clearing an important milestone as the US continues to grapple with a surge in new infections.

The US biotech firm’s breakthrough is one of the most promising developments yet in the race to develop a vaccine against the virus that has paralysed the world’s economy. Yet the road to a successful shot is filled with hurdles, and some patients in the trial experienced severe side effects.

Moderna’s shares gained about 18 per cent in US on Wednesday, as stocks of other companies researching vaccines for the virus also rose. Moderna’s stock has almost quadrupled in value this year on hopes that the company’s vaccine will gain rapid approval. The vaccine will move into a much larger late-stage trial later this month that’s likely to determine whether it’s fit for commercial use.

“The good news is that this vaccine induced antibodies,” said Anthony Fauci, director of the National Institute of Allergy and Infectious Diseases. “Not just any kind of antibodies, but neutralising antibodies.”

Fauci called the Moderna data “really quite promising”. Though he said the side effects seen were not alarming and were typical of those experienced with other vaccines, some experts sounded a note of caution.

More than half of participants who got the middle of three doses administered in the trial suffered mild to moderate fatigue, chills, headache, and muscle pain. Also, 40 per cent of people in the middle-dose group experienced a fever after the second vaccination. Three of 14 patients given the highest dose experienced severe side effects, but that dose is not being used in larger trials.