There’s a long list of coronavirus vaccine candidates in development right now, but it’s too early to say which will enter production. Investors have been quick to jump on any public companies that have COVID-19 vaccine candidates in development, although it’s still very early in the process.

Here are some of the coronavirus vaccine candidates

The World Health Organization is keeping a list of coronavirus vaccine candidates in development here. Toward the top of the list, you'll see the RNA COVID-19 vaccine candidate from Moderna and the National Institute of Allergy and Infectious Diseases.

Also on the list are Sinovac's effort, the non-replicating viral vector candidate from the University of Oxford, Inovio Pharmaceuticals' DNA vaccine, and the RNA vaccine candidate in development by Pfizer with BioNTech and Fosun Pharma. The Wuhan Institute of Biological Products is also working on a coronavirus vaccine candidate with Sinopharm, and the Beijing Institute of Biological Products is also working on one with Sinopharm.

Other companies listed on the list of COVID-19 vaccine candidates are Janssen Pharmaceutical, Altimmune, GeoVax and BravoVax, Valo Therapeutics, Sanofi Pasteur and GlaxoSmithKline, and Novavax.

The WHO's list of coronavirus vaccine candidates is five pages long, illustrating just how much effort is being put into finding a vaccine for the deadly virus.

Types of vaccines

Researchers are looking into four different approaches for creating a vaccine. The process usually takes years, but they are combining trial phases and taking other steps to shorten the process due to the severity of the pandemic right now. Over 100 different teams of scientists around the world are trying their hand at developing a vaccine for the coronavirus, which has sickened nearly 5 million people and taken about 325,000 lives.

Nature explained what questions scientists must ask as they test each coronavirus vaccine candidate. The most obvious question is about what kind of immune response the vaccine will cause and whether it effectively prevents COVID-19. Another question is whether each vaccine is safe, while another is how to know if it will actually work.

Finally, researchers must determine that if immunity does develop from any vaccine, how long will it last?

Here's what's happening now in the COVID-19 vaccine candidate effort

The U.S. Department of Health is providing up to $1.2 billion to speed up the development of AstraZeneca's coronavirus vaccine candidate. The money will also secure 300 million doses of the vaccine for the U.S. The vaccine candidate is being developed by the University of Oxford and licensed to AstraZeneca.

The deal allows for a late-stage Phase 3 clinical trial of the vaccine involving 30,000 people in the U.S. AstraZeneca said it has secured agreements for at least 400 million doses of the vaccine and arranged manufacturing for 1 billion doses. Deliveries of the vaccine are set to start in September, according to Reuters. The U.S. government also has deals with Johnson & Johnson, Moderna and Sanofi.

In other parts of the world, preparations are also being made to manufacture vaccines. The Serum Institute of India is the biggest vaccine maker by volume, and it has set aside one of its facilities to produce up to 400 million doses of Oxford's vaccine per year.

Next steps

About 100 different coronavirus vaccine candidates are in the works, so it will be some time before researchers know which candidate will be the best one to put into mass production. At lease six of those COVID-19 vaccine candidates are now being tested for safety in humans. The next step will be to determine which vaccines actually do what they're supposed to do, which is prevent infection with the novel coronavirus.

Nature explained that the vaccine trials involve giving thousands or tens of thousands of people the vaccine candidate or a placebo and then watching over months or years whether there is a difference in the number of people who get infected between the two groups. The trials are also focused on ensuring that the vaccines are safe.

Due to the COVID-19 pandemic, officials are speeding up the rate of vaccine development because it's thy only way to fully protect the world's population. Despite the fact that millions of people have been infected, many still haven't been exposed to it, so the human race is a long way from herd immunity.

Which coronavirus vaccine candidates to test first

The World Health Organization is planning a trial to test multiple COVID-19 vaccine candidates in a single study. Such an undertaking has never been attempted before, and vaccines have never been tested in such a short timeframe. The WHO's study will allow for more vaccine candidates to be added to the trial on a regular basis. Candidates that don't appear to work can be easily dropped from the trials.

As far as which coronavirus vaccine candidates will be tested first, researchers will look at production capacity and the amount of immune response generated in early trials and animal studies. Nature notes that some of the types of vaccines that are being developed, like RNA vaccines, which Bill Gates is excited about, haven't been tested widely in humans. The RNA method also hasn't been used in any vaccine that has previously won approval by regulators.

One other issue with testing multiple vaccine candidates is figuring out how each of them compares to each other. The WHO's trial could allow vaccines to be compared to each other, but some developers might not want to do it because such a trial could impact their vaccine's commercial prospects.

Another way to accelerate coronavirus vaccine candidates

Mass-scale trials will play an important role in the development of each coronavirus vaccine candidate, but there is a possibility that regulators could approve emergency deployment of them. Nature said one possibility is to look for signs in early-state trials that a vaccine candidate works in hundreds of patients and then seek approval from regulators to administer the vaccine to high-risk groups like healthcare workers.

The U.S. Food and Drug Administration can grant such emergency deployment measures while more data is being collected to license a particular vaccine. So far, no vaccine has ever been given out under emergency provisions. If the coronavirus vaccine does follow that path, regulators will want to be sure that it's safe before issuing emergency approval.

Believe it or not, some are advocating a more radical approach to getting COVID-19 vaccine candidates approved faster. This would involve intentionally infecting volunteers who are young and healthy, which would mean that study administrators wouldn't need to wait and see if trial participants become infected naturally. This process is already being used for diseases like dengue fever and malaria. However, without an effective treatment, such a process would be extremely risky because there would be no way to know which young, healthy volunteers will develop life-threatening symptoms from the disease.