Medical device company Johnson & Johnson on Friday announced the results of the third phase clinical trial of its coronavirus vaccine candidate, which was found to be 66% effective in preventing moderate to severe infections. The company also said that the vaccine was 85% effective in preventing severe diseases, regardless of the variations, 28 days after inoculation in all adults.

In its study, severe coronavirus disease was defined as confirmed cases of the coronavirus along with one or more symptoms, including admission to an intensive care unit, respiratory failure, shock, organ failure or death, among other factors. Moderate coronavirus disease was defined as a confirmed case of the infection with symptoms including evidence of pneumonia, deep vein thrombosis, shortness of breath or abnormal blood oxygen saturation above 93%, abnormal respiratory rate, among others.

It said that the efficacy of the vaccine, developed by its Belgian pharmaceutical company Janssen, increased over time with no cases of the coronavirus being reported among those inoculated after day 49.

“The Janssen Covid-19 vaccine candidate demonstrated complete protection against Covid-related hospitalisation and death, 28 days post-vaccination,” the company said in a statement. “There was a clear effect of the vaccine on Covid-19 cases requiring medical intervention [hospitalisation, ICU admission, mechanical ventilation, extracorporeal membrane oxygenation], with no reported cases among participants who had received the Janssen Covid-19 vaccine, 28 days post-vaccination.”

The protection against moderate to severe Covid-19 infection was 72% in the United States, 66% in Latin America and 57% in South Africa, 28 days following the vaccination.

Paul Stoffels, chief scientific officer at Johnson & Johnson, said that the results using a single-shot vaccine represents a promising moment. “A one-shot vaccine is considered by the World Health Organization to be the best option in pandemic settings, enhancing access, distribution and compliance,” he said. “Eighty-five percent efficacy in preventing severe Covid-19 disease and prevention of Covid-19-related medical interventions will potentially protect hundreds of millions of people from serious and fatal outcomes of Covid-19.”

The company said that it was studying whether giving two doses will give either stronger or longer-lasting protection. The vaccine candidate is also consistent with standard distribution channels. Johnson & Johnson said the vaccine can remain stable for two years at -20 degree Celsius with it being kept at a temperature of 2-8 degree Celsius for at least three months.

A concurrent review of the phase 3 trial by the Data and Safety Monitoring Board, an independent group of experts, showed that the vaccine did not report any significant safety concerns.

The company said that it will file for Emergency Use Authorisation in the United States in early February and expects to have the product shipped immediately after the vaccine gets approved. The third phase trial involved 43,783 participants.

The United Kingdom has pre-ordered 30 million (3 crore) doses of the Janssen vaccine, while the US has ordered 100 million (10 crore) doses and Canada 38 million (3.8 crore), reported BBC.