Early data on a possible COVID-19 vaccine show that it triggered an immune response in all 45 people tested, researchers announced Tuesday.
The preliminary results of the study, published in the New England Journal of Medicine, were cautiously viewed as a significant step to quickly develop a vaccine for a virus that has shut down countries and economies around the globe and killed more than 576,000 people so far, including more than 136,000 in the US.
The experimental drug, given in two doses, was developed by Cambridge, Massachusetts–based Moderna Therapeutics and supported by the National Institutes of Health, which began safety testing on 45 subjects in March.
The vaccine being developed by Moderna, mRNA-1273, is one of among more than 155 vaccines, 23 of which are in human clinical trials, being tested and developed around the globe in hopes of curbing the worldwide pandemic.
Moderna is one of six companies that have received significant funding from the federal government to develop a vaccine, part of a $4 billion initiative called "Operation Warp Speed." Moderna has received upward of $500 million as part of the effort.
The Phase 1 study showed that two doses of the vaccine were able to trigger the production of "neutralizing" antibodies that can help prevent future infections in all 45 people tested. While the study concluded that the virus was safe, some individuals experienced mild side effects including fatigue, chills, headaches, and muscle pains — common symptoms experienced by people with COVID-19.
On Tuesday, Moderna posted an announcement about their Phase 3 clinical trial, slated to begin on July 27. That trial, named the COVE study, will test 30,000 healthy individuals to see how effective the vaccine is at preventing coronavirus infections versus control subjects who receive a placebo. The study will also look more closely at whether the possible vaccine might affect older adults or those with chronic conditions.
Another Warp Speed effort spearheaded by Pfizer is also expected to begin Phase 3 trials in July.
"These positive Phase 1 data are encouraging and represent an important step forward in the clinical development of mRNA-1273, our vaccine candidate against COVID-19," Stéphane Bancel, chief executive officer of Moderna, said in a statement.
Although drug companies and governments across the world have been rushing to find an effective vaccine, the length of time that the vaccine is effective is also an important factor as health officials look to push back against the pandemic.
"What we're going to do is hope that when we do vaccinate individuals, that the vaccine would give protection that's at least long enough for one full seasonal cycle," Fauci said Tuesday while speaking at an event at Georgetown University. "Hopefully much more, but if it isn't, there's always the opportunity to give someone a booster."
It's unclear how long the drug developed by Moderna would continue to be effective in test subjects, but the company said subjects would continue to be monitored for one year after receiving the two doses.
"[Moderna} hopes to achieve a shared goal that the participants in the COVE study are representative of the communities at highest risk for COVID-19 and our diverse society," the statement from the company read.
Four other drugs have entered Phase 3 testing, according to the New York Times.
If the drug proves to be effective, Moderna said the company would be able to make between 500 million to 1 billion doses a year beginning in 2021 — reaffirming that even if an effective vaccine is developed, it could still be months before it is available to the public.