CHICAGO (CBS Chicago/CBS News/AP) — Promising results were announced Tuesday for a possible COVID-19 vaccine with ties to Chicago.

The company that makes it, Moderna, announced late Tuesday that the mRNA-1273 vaccine has induced immune responses in all volunteers in this Phase 1 study, just the way scientists would hope.

“No matter how you slice this, this is good news,” Dr. Anthony Fauci, the U.S. government’s top infectious disease expert, told The Associated Press.

“It’s a promising result. We are very excited about it,” said Dr. Richard Novak, chief of infectious diseases at the University of Illinois at Chicago Medical Center, where part of a broader Phase 3 trial will take place.

The vaccine induced binding antibodies to the coronavirus spike protein after the first vaccination, a Moderna news release said.

The vaccine requires two doses, a month apart. It was given 28 days apart beginning in March, in three dose levels to 45 healthy participants between the ages of 18 and 55.

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The early volunteers developed what are called neutralizing antibodies in their bloodstream — molecules key to blocking infection — at levels comparable to those found in people who survived COVID-19, the research team reported in the New England Journal of Medicine.

“This is an essential building block that is needed to move forward with the trials that could actually determine whether the vaccine does protect against infection,” said Dr. Lisa Jackson of the Kaiser Permanente Washington Research Institute in Seattle, who led the study.

There’s no guarantee, but the government hopes to have results around the end of the year — record-setting speed for developing a vaccine.

“Our goal is to have a vaccine available for broad distribution by year-end or early next year,” Moderna president Stephen Hoge told “CBS This Morning” in May, after seeing preliminary data on the Phase 1 trial. “If we and others build data that shows that the vaccine has a potential for benefit, that it’s safe and has a potential for efficacy, then, of course, there are circumstances where the vaccine could be deployed to high-risk populations earlier under something called an Emergency Use Authorization. Really though, that’s a decision that regulators, in particular the FDA, have to make.”

Moderna said the vaccine was “generally safe and well-tolerated.”

“The most commonly reported systemic adverse events following second vaccination at the 100 µg (microgram) dose were fatigue (80%), chills (80%), headache (60%) and myalgia (53%), all of which were transient and mild or moderate in severity,” Moderna said in the news release. “The most common solicited local adverse event at the 100 µg dose was pain at the injection site (100%), which was also transient and mild or moderate in severity.”

For three participants given the highest dose, those reactions were more severe, but that dose isn’t being pursued.

Some of the reactions at the dose that is being pursued are similar to coronavirus symptoms, but they’re temporary, lasting about a day and occur right after vaccination, researchers noted.

“Small price to pay for protection against COVID,” said Dr. William Schaffner of Vanderbilt University Medical Center, a vaccine expert who wasn’t involved with the study.

He called the early results “a good first step,” and is optimistic that final testing could deliver answers about whether it’s really safe and effective by the beginning of next year.

“It would be wonderful. But that assumes everything’s working right on schedule,” Schaffner cautioned.

Tuesday’s results only included younger adults. The first-step testing later was expanded to include dozens of older adults, the age group most at risk from COVID-19. Those results aren’t public yet but regulators are evaluating them, and Fauci said final testing will include older adults, as well as people with chronic health conditions that make them more vulnerable to the virus — and Black and Latinx populations likewise affected.

The next step will be a 30,000-participant Phase 3 study set to start July 27. Some of the volunteers for that study will be in Chicago.

UIC will be one of the institutions conducting the study at the end of the month.

Jean Tsai is one of those who signed up for the UIC clinical trial.

“I signed up right before 4th of July, and hopefully I’ll get into it. I’m really excited,” Tsai told CBS 2’s Charlie De Mar. “It would be a great way to participate in helping us get back to normal.”

Dr. Novak will oversee the Phase 3 trial at UIC. The 1,000 participants in Chicago will either receive the vaccine or a placebo, and be monitored throughout.

Like in the Phase 1 trial, the will receive one injection at the start and again after a month.

In all, 30,000 people will be studied for Phase 3 at dozens of hospitals.

“It’s unprecedented in its size and speed, so there’s a lot of preparation involved,” Novak said.

As cases of COVID-19 continue to climb, this next testing phase is a possible step closer to a vaccine.

“You never know until you do the study,” Novak said.

Some of the criteria to be part of the study are being more likely to get COVID-19 – people who work in warehouse factory settings, people 65 and older, and those with pre-existing conditions.

UIC focus on hard-hit communities, like Pilsen, Little Village, and Englewood for people to take part in the trial. They’ll be given a placebo or the vaccine to determine if the vaccine works.

The study at UIC had been set to begin July 9, but was delayed until July 23 as it awaited Food and Drug Administration approval and researchers made sure they have enough doses of the vaccine and the placebo.

If the Phase 3 trial goes well, regulators would have to give final approval. Moderna said it will have as many as a billion doses beginning next year.

Nearly two dozen possible COVID-19 vaccines are in various stages of testing around the world. Candidates from China and Britain’s Oxford University/a> also are entering final testing stages.

The NIH-developed shot from Moderna isn’t the only one set for such massive U.S. testing, crucial to spot rare side effects. The government plans similar large studies of the Oxford candidate and another by Johnson & Johnson; separately, Pfizer Inc. is planning its own huge study.

Already, people can start signing up to volunteer for the different studies.

People think “this is a race for one winner. Me, I’m cheering every one of them on,” said Fauci, who directs NIH’s National Institute of Allergy and Infectious Diseases. “We need multiple vaccines. We need vaccines for the world, not only for our own country.”

Around the world, governments are investing in stockpiles of hundreds of millions of doses of the different candidates, in hopes of speedily starting inoculations if any are proven to work.

CBS 2’s Charlie De Mar contributed to this report.

(© Copyright 2020 CBS Broadcasting Inc. All Rights Reserved. CBS News and The Associated Press contributed to this report.)