Modern coronavirus vaccine shows ‘promising’ results in published Phase 1 study

“We think the immune responses look promising, but we don’t know if the levels we are seeing would really protect against infection. It is really difficult to know until the efficacy trial is done,” he said. “So we are laying the groundwork for the judgment that will provide those answers.”

Moderna hopes to begin the company’s largest study of the Covid-19 mRNA-1237 vaccine candidate on July 27, according to details released separately on Tuesday. It is expected to be the first in the United States to begin Phase 3 trials.

For now, the new study “quickly provided information that could be used to determine what dose to go through with the Phase 2 and Phase 3 trials. That’s a critically important decision to make and have that information available as soon as the Vaccine trial is quite remarkable, “Jackson said.

A Phase 1 study generally studies a small number of people and focuses on whether a vaccine is safe and elicits an immune response.

“We want to know if the vaccine is safe and effective”

The Phase 1 study included 45 healthy adults, ages 18 to 55, who received two shots from the mRNA-1237 vaccine candidate 28 days apart. Some of the volunteers enrolled in the trial at Kaiser Permanente in Seattle and others at Emory University in Atlanta.

The volunteers were separated into groups where they received the vaccine in a dose of 25, 100 or 250 micrograms. They received their first vaccine between March 16 and April 14.

“The first dose establishes the immune system, it’s called priming,” said Jackson. “So when you do the same thing again, there is a booster response. There is an increased response. So we didn’t think a vaccine would be enough to get the level of response we wanted to see.”

The researchers found “safety concerns not limited by trials” after the volunteers received their two doses of vaccine, but there were some mild to moderate side effects, such as some pain at the injection site, and there were more of them the higher the dose of the vaccine. the vaccine

After the first vaccination, five participants reported adverse events in the 25 microgram group, 10 in the 100 microgram group, and eight in the 250 microgram group. Then, after the second vaccination, such events occurred in seven of 13 participants in the 25 microgram group, 15 in the 100 microgram group and 14 in the 250 microgram group, and three of those participants reported “one or more serious events, “according to the study.

The most commonly reported systemic adverse events after the second vaccination at the 100 microgram dose were fatigue, among 80%; chills, between 80%; headache, between 60%; and myalgia or muscle pain, between 53%; all of which were transitory and of mild or moderate severity, as noted in the Moderna press release.

The study data also showed that the vaccine induced an antibody response. Antibodies are proteins that the body produces to fight infection.

Specifically, according to the study, all participants developed neutralizing antibodies to the virus at levels similar to those seen in people who naturally recovered from Covid-19. Neutralizing antibodies bind to the virus, preventing it from attacking human cells.

The researchers measured two types of immune responses, Jackson said.

“These two types of responses are mutually supportive. We know that the antibodies are being produced and it appears that after vaccination there is a function that serves to block the virus’s ability to enter cells. Therefore, it neutralizes the activity of the virus “, said. said.

But more research is needed.

“What do we really want to know? We want to know if the vaccine is safe and effective, that’s what we want to know,” said Dr. Paul Offit, a member of the NIH panel that is establishing a framework for vaccine studies. in the United States, which was not involved in the new study.

With the study, “we know it is safe for 45 people, that it will not be the 20 million or 200 million people who will get it here in the United States,” said Offit, who is also director of the Vaccine Education Center and a treating physician at the Division of Infectious Diseases at Children’s Hospital of Philadelphia.

“So we know that you don’t have a very common side effect problem, that’s what we know,” he said. “So we don’t know anything about efficacy, which is what we really want to know. Is this vaccine going to work? The only way to find out is to do a so-called Phase 3 trial.”

Moderna hopes to start a large trial of the Covid-19 vaccine in the US in late July

The results of the Phase 1 study can help guide the look of the Phase 3 study.

“These Phase 1 data demonstrate that vaccination with mRNA-1273 elicits a robust immune response at all dose levels and clearly supports the choice of 100 μg in a prime and boost regimen as the optimal dose for the Phase 3 study. “Dr. Tal Zaks, Moderna’s medical director, said in the company’s press release on Tuesday.

“We look forward to beginning our Phase 3 study of mRNA-1273 to demonstrate the ability of our vaccine to significantly reduce the risk of COVID-19 disease,” he said.

For the Phase 3 study, the researchers plan to enroll 30,000 adult participants, including people whose locations or circumstances put them at high risk for infection. One group will receive 100 micrograms of the vaccine on Day 1 and again on Day 29. A second group will receive two doses of a placebo to compare.

Fourteen days after the participants receive their second dose, the researchers will analyze whether they develop Covid-19. Participants will be followed for two years after receiving their second dose.

The study will be conducted at 87 locations in the United States.

Moderna’s vaccine candidate is one of 23 in clinical trials worldwide, according to the World Health Organization.

Overall, “the safety and immunogenicity data in this preliminary report are promising and support the continued development of this vaccine. However, we must take into account the complexity of vaccine development and the work that remains to be done before Covid-19 vaccines are widely available, “wrote Dr. Penny Heaton, executive director of the Bill and Melinda Gates Foundation, in an editorial accompanying the Phase 1 study in the New England Journal of Medicine on Tuesday.

“Accelerating the development of Covid-19 vaccine candidates beyond phase 1 depends on continuous parallel monitoring of abundant activities and resources. The world has witnessed the compression of 6 years of work in 6 months,” wrote Heaton. . “Can the multiverse vaccine do it again, leading to the reality of a safe and effective Covid-19 vaccine for the most vulnerable in the next 6?”