The news of a confirmed effective vaccine, while still many months away, has from the start of this pandemic been the awaited panacea for economic recovery — even though we are still probably a year away from it being deployable at scale. And the first really good news about one much-talked-about vaccine has just arrived.

The small-scale Phase 1 trial of a SARS-CoV-2 vaccine developed using new technology by Massachusetts-based biotech firm Moderna has produced extremely promising results in a group of eight healthy volunteers, as the New York Times reports. The volunteers who received doses of Moderna's vaccine all produced antibodies sufficient to fend off the coronavirus, researchers say — with two rounds of lower doses proving just as effective as higher doses. While only preliminary and still not proof that the vaccine will work in the real world against the live virus, the news has sent the stock market into giddy territory, with the Dow Jones Industrial Average up nearly 1,000 points since Monday morning trading began.

"This is a very good sign that we make an antibody that can stop the virus from replicating,” said Moderna CEO Stephane Bancel in an interview with the LA Times. He said the data "couldn’t have been better," and the company is now moving ahead in planning a broader third-phase trial — a second phase involving 600 volunteers already got the go-ahead from the FDA two weeks ago.

The third phase of the trial will be the crucial one, involving thousands of healthy volunteers, and that is now set to begin in July.

The first phase of the trial, which is ongoing, involves safety testing in healthy volunteers, looking for side effects and adverse effects from the vaccine itself. Per the New York Times, older volunteer groups will be getting test doses of the virus as part of the continuing initial phases, with groups aged 55 to 70, and 71 and over.

In the first group, aged 18 to 55 years old, 45 healthy people in the Seattle area volunteered to receive doses of the experimental vaccine in mid-March, in a trial done in collaboration with the National Institute of Allergy and Infectious Diseases — headed by Dr. Anthony Fauci. Of those, 25 of the participants received lower-dose levels of the vaccine (25 to 100 micrograms), and reactions were largely mild and "typical of vaccines," according to Bancel. Three volunteers who received higher doses of 250 micrograms experienced more severe side effects, according to this company presentation. And one who received a third, middle dose of the vaccine between the two doses given to the other patients showed redness around the injection site.

Side effects included fever, muscle aches, and fatigue, and all resolved themselves within in about a day.

Only eight of the 25 volunteers receiving the lower doses were able to participate in follow-up antibody testing because of the length of time it required. But of those eight, the volunteers who received the smallest vaccine doses of 25 micrograms showed antibody levels equivalent to patients who have recovered from COVID-19. The volunteers who received 100 micrograms had antibody levels that “significantly exceeded” recovered COVID patients, per New York Magazine.

Antibodies produced were also shown to be effective at fighting the virus in test tubes.

In upcoming phases of the trial, researchers will be trying to strike a balance around the effectiveness of the vaccine at lower doses — because the lowest effective dose will allow for greater production volume when the time comes. As chief medical officer Tal Zaks tells the NYT, the new vaccine, if proven effective and approved, could go into production by late 2020 or early 2021 — an aggressive timeline that President Trump was already quoting over the weekend, and one which some researchers say is irresponsible given the possibility of as-yet undiscovered adverse effects that can take lengthy human trials to find. After the results of the first phase, Moderna already knows it does not have to use the higher doses in the next phases.

"We’re doing our best to make it as many millions [of doses] as possible [when the time comes]," Zaks says to the Times. "The lower the dose, the more vaccine we’ll be able to make."

Moderna's vaccine, based on untested mRNA technology for vaccine production, is one of dozens currently in trials around the world. And experts say that because of the challenges of scaling up production for billions of doses, it is important that other countries attempt to develop their own vaccines as well.

The new technology depends on the body's own cells to produce viral proteins resembling the "spikes" of the real virus, using virus RNA to cause this protein production that then triggers the body to produce its own antibodies blocking the spike from doing its dirty work. Typical vaccines would use inactive pieces of a virus to do the same thing, hopefully creating long-lasting immunity.

Earlier reports have discussed how vaccine trials typically involve animal testing, and the ethical issues around intentionally exposing healthy volunteers to a potentially deadly virus in order to test a vaccine's true effectiveness — something called human challenge trials. The alternative is simply to give test subjects doses of the vaccine and see who ends up COVID-positive in the normal course of their lives — a process which is less controversial but requires much more time. The critical issue in testing the vaccine will be whether it causes disease enhancement — an uncommon but not unknown effect of some earlier experimental vaccines.

As the Wall Street Journal reported last week, the debate is raging in the medical community about whether the risks of a human challenge trial are worth it in the case of this virus, and the World Health Organization has already published a document outlining the "ethical acceptability" of such a trial. Experts say that an accelerated human challenge trial would only occur in order to produce an emergency vaccine for use only in high-risk groups, and no matter a broader, lengthier human trial as described above would still need to take place before global-scale vaccine production could commence.

It also remains unclear how long immunity will last from a vaccine when it comes to this virus — and whether mutations will require annual vaccinations as is the case with influenza.

Previously: Coronavirus Vaccine Begins Testing On Volunteers In Seattle