(Reuters) - Johnson & Johnson said its single-dose vaccine was 72% effective in preventing COVID-19 in the United States but a lower rate of 66% was observed globally in the large trial conducted across three continents and against multiple variants. In the trial of nearly 44,000 volunteers, the level of protection against moderate and severe COVID-19 was just 57% in South Africa, where a particularly worrying variant of the novel coronavirus is circulating. Following are initial reactions to the report: Moncef Slaoui, Ph.D. Collaborator on the trial and Former Chief Scientific Advisor to Operation Warp Speed: “This is very important, and impactful data in terms of public health and intervention in the setting of a raging pandemic” “The ease of immunisation - completing immunisation with one shot vaccine - with a vaccine that can be transported and kept stable for a period of two or three months at fridge temperature, is going to be super important” Michael Breen, Director of Infectious Diseases and Ophthalmology, GlobalData “The reason JNJ’s vaccine may be ideal for stemming the tide of the outbreak is because it provides strong, if comparatively lower, protection against COVID-19 but with a single dose. For now, most countries are still desperate to get their hands on doses, regardless of whether or not the vaccine is considered highly effective, moderately effective will do just fine for now.” Dr Gregory Poland, a virologist and vaccine researcher with the Mayo Clinic in Rochester, Minnesota: “It is a needed weapon in fighting this pandemic, especially in a world with an insufficient supply of vaccine and especially given its one-dose format and ability to remain stable for long periods of time at refrigeration temps.” “At lower efficacy, we don’t yet know about the durability of protection.” Mark Siedner, infectious disease clinician at Massachusetts General Hospital and associate professor of medicine at Harvard Medical School: “We’re preliminarily thrilled. We want these vaccines to do two things. The most important of which is stop people from getting sick and this this vaccine almost very clearly appeared to do that pretty similarly to the Moderna and Pfizer vaccines.” “It’s a one dose regimen. It has a lower price point, it’s stable in standard refrigerators and when we’re talking about global epidemic control I think these are precisely the words that if you really want to hear. It’s going to be welcome news for the global COVID-19 response.” Dr. William Schaffner, professor of infectious diseases at the Vanderbilt University Medical Center: “We’re trying to get to 80 plus percent of people vaccinated in order to generate the herd immunity, this vaccine would certainly help us get there.” “Down the road we’re, having to prepare people already. They may have to get a booster dose of a new vaccine, at some point in the future. Because it’s this virus that’s playing the tune we’re having to dance to.” Dr. Walid Gellad, a health policy associate professor at the University of Pittsburgh: “Right now, any protection and additional vaccine is great. The “South Africa” strain is still uncommon in the U.S. and obviously we would want to see higher efficacy, but the key is not only overall efficacy but specifically efficacy against severe disease, hospitalization, and death. It’s unlikely we’re going to completely eliminate Covid anytime soon, but the key is to make it a minor nuisance instead of a deadly disease. This is one shot in the arm and good efficacy. Great news.” Glenda Gray, the joint lead investigator of the South African vaccine trial. “I am overwhelmed by the fact that this vaccine protected against severe disease even in South Africa.” Gray, who is the chief executive of the South African Medical Research Council said this is by far the best vaccine for South Africa and can prevent a large number of hospitalisations and deaths in the country. Linda-Gail Bekker, the other joint lead investigator on the vaccine trial in South Africa. “We are hoping the vaccine could be approved in the country by mid February as the regulator has said it will fast-track the approval process.”