Massachusetts-based organization Moderna announced on Monday that its Coronavirus vaccine was 94.5 percent effective, joining Pfizer as a front-runner in the global race to keep the pandemic under control. The United States government gave $1 billion in aid to the planning and testing of the Moderna Covid vaccine.

Several leading coronavirus vaccine stocks were sinking after Moderna (NASDAQ: MRNA) announced interim efficacy results for its COVID-19 vaccine candidate mRNA-1273.

Shares of Pfizer (NYSE: P.F.E.) were down 3.9% as of 11:19 AM EST on Monday.

Meanwhile, BioNTech (NASDAQ:BNTX) and Novavax (NASDAQ:NVAX) stocks were falling 13.2% and 10.6%, respectively. Moderna says it is a "great day".

Alex Azar, US Health and Human Services secretary, praised the Moderna coronavirus vaccine trial news on Good Morning America. There's more work to be done before they'll know if the vaccine really is safe and effective. The company is now expected to apply for emergency authorization from the F.D.A. Meanwhile, the United States is enduring an overwhelming blast of new cases of Covid-19.

Political bodies are not immune from this either. Several weeks ago, President Donald Trump was hospitalized with COVID-19. Senator Grassley has also tested positive for COVID-19.

More than 30,000 people in the U.S. aged 18 and over are taking part in the Moderna vaccine phase III trial. Half of the participants were given a placebo rather than the actual vaccine. The company reported that 11 people in the trial's placebo arm developed severe cases of COVID-19, whereas no one in the vaccinated group did.

Covid vaccines might be available as early as next month, says Fauci: "Towards the latter part of December, rather than the early part of December." Moderna says it expects to ask The U.S. Food and Drug Administration to authorize use by early December.

What about those who became ill?

For most, the disease is mild; however, some people die. Covid-19 is a mild infection for eight out of 10 people among adults aged 65 years and older who get it, reports CDC. The core symptoms are a fever and a cough.

Body aches, sore throat, and a headache are all possible. Out of the 95 individuals who became ill in the Moderna study, 11 experienced a severe infection. The five immunized individuals who became sick experienced just gentle manifestations, and the entirety of the severe cases were members of the placebo treatment.

Natalie Dean, a biostatistician at the University of Florida, told The New York Times: "It couldn't be a more favorable split."

The vaccines deliver messenger R.N.A., or mRNA, a genetic recipe for making the spikes that sit atop the coronavirus.

Once injected, the body's immune system produces antibodies to the spikes. If a vaccinated person is later exposed to the coronavirus, those antibodies should be ready to attack the virus.

Who participated in Moderna's vaccine trial?

Moderna enlisted 30,000 volunteers from all over the United States to take part in its trial. Twenty-five percent of the members are 65 years or older. White individuals make up 63 percent. In a recent press release, Moderna said: "Preliminary analysis suggests a broadly consistent safety and efficacy profile across all evaluated subgroups."

Moderna's results vs. Pfizer's

On November 9, New York City-based drug company Pfizer announced that it now offers the first compelling evidence that a vaccine can prevent COVID-19 — and bodes well for other COVID-19 vaccines in development.

Although the company did strike a deal worth $1.95 billion for the U.S. government to purchase 100 million doses of the vaccine, it emphasized that it received no federal funding for vaccine research and development.

However, Pfizer gave less detail in its declaration a week ago on November 9 than Moderna did on Monday, November 16. Pfizer's information does not answer key questions that will determine whether its vaccine and others like it can prevent the most severe cases or quell the coronavirus pandemic.

Pfizer tested 94 volunteers and assessed that the adequacy of its vaccine was "95% effective and safe." One of the main differences between the two vaccine candidates is how they are stored.

Both require two doses, but Pfizer's vaccine has to be stored at minus 94 degrees Fahrenheit or colder, which has raised practical concerns about how they could be shipped and disseminated. Moderna's vaccine does not require ultracold storage and can remain stable at regular refrigeration levels — between roughly 36 to 46 degrees Fahrenheit — for 30 days.

Both Pfizer and Moderna far surpass the F.D.A.'s requirement that Covid-19 vaccines have more than 50% viability.

Pfizer didn't report the number of volunteers who had extreme Covid-19 or how many of those individuals got the vaccine. More details are expected to be released in the next upcoming weeks.

Other vaccine candidates in the race

Although they have their differences, Pfizer and Moderna vaccines are quite comparative.

Both shots rely on a technology called messenger R.N.A. that has never been used before to develop an approved vaccine. The approach is designed to transform the body's own cells into vaccine-making factories. The vaccines instruct cells to make copies of the coronavirus's spike protein, stimulating the creation of protective antibodies.

Different groups have made coronavirus vaccines that are dependent on another infection called an adenovirus, for example. Researchers have announced positive results for the final human stages of a coronavirus vaccine trial. This time, the results are from the Russian vaccine trial, dubbed Sputnik V., and it was proven to be more than 90% successful.

AstraZeneca and Johnson & Johnson have restarted their late-stage trials after finding that serious illnesses in a few volunteers appeared not to be related to the vaccines.

Both companies are using adenoviruses, which typically cause harmless colds.

The vaccine candidate of Novavax, a U.S. company, is also composed of the spike protein.

How long will the Covid vaccines last?

We don't have a clue. Both Moderna and Pfizer began their trials on July 27, thus they have had the option to follow their volunteers for a couple of months up until this point.

It's possible that the antibodies give durable security or blur away in less than a year and require a sponsor.

What happens now?

Both the Moderna and Pfizer trials are proceeding to assemble more information from enormous investigations. Since both organizations hope to apply to the Food and Drug Administration in the following weeks to begin providing vaccines to the general population, it hangs in the balance about what will happen then.

The F.D.A. will survey the applications and talk with its own outer advisory group of specialists before settling on a decision.

Following the F.D.A.'s review of a new indication license application, the sponsor and the F.D.A. may present their findings to F.D.A.'s Vaccines and Related Biological Products Advisory Committee (VRBPAC). This non-FDA expert committee (scientists, physicians, biostatisticians, and a consumer representative) provides advice to the Agency regarding the vaccine's safety and efficacy for the proposed indication.

Is it safe to travel for the holidays this year?

The end of the year is sneaking up, and people are weighing travel plans to join friends and family for the holidays against the backdrop of a surge of the Covid-19 pandemic.

Health and government officials are increasingly urging people to stay home and avoid nonessential travel. The US Centers for Disease Control and Prevention says that travel increases contracting and spreading Covid-19: "Staying home is the best way to protect yourself and others," the C.D.C. says.