CHICAGO – Moderna Inc’s experimental vaccine for COVID-19 has been shown to be safe and elicited immune responses in 45 healthy volunteers in an early-stage study, American researchers reported on Tuesday. reported mild or moderate reactions such as fatigue, headache, chills, muscle pain or pain at the injection site, which were more likely to occur after the second dose and in people who received the higher dose, The team reported in the New England Journal of Moderna stocks jumped more than 15% in after-hours trading on Tuesday. Moderna was the first to begin human testing for a vaccine against the new coronavirus. March 16, some 66 days after the genetic sequence of the virus was released. say that a vaccine is needed to end the pandemic that has made millions of people sick and has caused nearly 575,000 deaths worldwide. “The world urgently needs vaccines to protect themselves from COVID-19,” said Dr. Lisa Jackson of Kai Ser Permanente Washington Health Research Institute in Seattle and lead author of the study. The federal government is supporting the vaccine Moderna with almost half a billion dollars and chose it as one of the first to enter large-scale human trials. A successful vaccine could be a turning point for Moderna, based in Cambridge, Massachusetts, which has never had a licensed product.The Moderna vaccine, mRNA-1273, uses ribonucleic acid (RNA) – a chemical messenger that contains instructions for making proteins. When injected into people, the vaccine instructs cells to make proteins that mimic the outer surface of the coronavirus, which the body recognizes as a foreign invader, and mounts an immune response against it. Results released Tuesday involved three doses of the vaccine, tested in groups of 15 volunteers aged 18 to 55 who received two shots, 28 days apart. The groups tested 25, 100 or 250 micrograms of the vaccine, and the team reported that people who received two doses of the vaccine had high levels of neutralizing antibodies that killed the viruses that exceeded the average levels seen in people who had recovered from COVID-19. Adverse events after the second dose occurred in seven of the 13 volunteers who received the 25 microgram dose, the 15 participants who received the 100 microgram dose, and the 14 who received the 250 microgram dose. In the highest dose group, three patients experienced severe reactions such as fever, chills, headache or nausea. One of them had a fever of 103.28 degrees Fahrenheit (39.6 ° C). “We have not seen any event that qualifies as a serious adverse event,” said Jackson, referring to reactions requiring hospitalization or resulting in death. In June, Moderna said it selected the 100-microgram dose for its advanced stage study to minimize side effects. At that dose, Moderna said the company is on track to deliver approximately 500 million doses per year, and possibly up to 1 billion doses per year, starting in 2021, of the company’s internal manufacturing site. company in the United States and strategic collaboration with the Swiss drug manufacturer Lonza. “It’s a good first step,” said Dr. William Schaffner, a vaccine expert from Vanderbilt University Medical Center who was not involved in the study. “There is nothing here that would prevent moving on to phase 2 / phase 3 trials,” he said. “A little tiredness and headache and myalgia (muscle pain) and pain at the injection site is a small price to pay for protection against COVID-19.” In April, Moderna expanded the Phase 1 trial to include adults over 55, who are at higher risk for serious illness, with the goal of recruiting 120 volunteers. Moderna said it will follow the study volunteers for a year after the second shot, to look for side effects and check the duration of immunity.