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The race to develop the first widely distributed coronavirus vaccine might be the most hotly pursued scientific frontier since the space race.

At least 147 potential COVID-19 vaccines are currently in development, according to the World Health Organization (WHO). The people and entities looking to fund a vaccine include world governments, such as the United States and its Operation Warp Speed plan; pharmaceutical firms, big and small; and even wealthy philanthropists like Bill Gates and Dolly Parton. So far, at least 17 have created potential vaccines that have reached human trials.

President Donald Trump and his new vaccine czar, Moncef Slaoui, have said that a vaccine could be ready for widespread distribution by the end of the year. But most public health experts have predicted a less optimistic timeline.

Dr. Marie-Paule Kieny, the director of research at the French National Institute of Health and Research (INSERM) and a former top WHO official, told VICE News that mid-2021 is more realistic to expect the hundreds of millions of doses that would need to be available for herd protection.

The WHO has even warned that the virus may never go away entirely.

“Although it is absolutely possible that a vaccine against COVID-19 can be developed, it is not impossible that the virus will continue to circulate and that we might need to be regularly immunized, like against flu,” Kieny said. “For the moment, all of this is hypothetical.”

How do clinical trials work?

In addition to various companies working on a vaccine, different kinds of vaccines are also being tested, including some that have never been approved for use in humans before.

Most commonly used vaccines are either inactivated, such as the flu shot, or live-attenuated, which is used for the measles and mumps. Some companies, however, are racing to develop genetic-based mRNA vaccines, which introduce a sort of code into the body’s cells to fool it into reproducing molecules of the virus, so the immune system can learn to fight it. No mRNA vaccine has ever been approved for use in humans, but if one is ultimately approved, it’ll be faster and cheaper to produce than conventional vaccines.

“The flu and measles vaccine, they’ve been tested thoroughly for a long time before we have the product,” University of North Carolina research associate Long Ping Victor Tse told VICE News. “We have a very good idea of what to do, but every virus and pathogen is different. Is it safe? Is it effective? All of this costs time and money to test.”

Before a vaccine is approved and widely distributed, it must go through preclinical animal trials and then several phases of human trials. A remarkably small number of vaccines make it to the final stage, so some developers are testing multiple vaccine candidates at once to find their best option.

The process, as described by the Food and Drug Administration (FDA), goes like this:

  • Phase I: Twenty to 100 either healthy or infected participants are given the vaccine to make sure it’s safe for human consumption and what dosage works best. Phase I takes several months, and roughly 70% of the drugs move on to the next stage.
  • Phase II: The vaccine is tested on up to several hundred infected people to make sure it’s efficient and that the side effects don’t outweigh the benefits. Phase II can take up to two years, and only about a third of the drugs reach Phase III.
  • Phase III: Also known as “pivotal studies,” Phase III trials aim to “demonstrate whether or not a product offers a treatment benefit to a specific population,” according to the FDA. Due to the breadth and span of the study, Phase III trials can also catch side effects that went unnoticed during the first two trial phases. The process usually takes between one and four years, and only about a quarter of the drugs make it through.
  • Phase IV: The product is continuously tested on thousands of people who have the disease to study effectiveness and long-term side effects. These trials are carried out after the FDA has approved the vaccine.

In some cases, companies are conducting combined Phase I/II or Phase II/III, in which they test for safety and for efficacy in hundreds or thousands of people.

A vast majority of what’s known about the various stages of these vaccines also comes from the developers, which have a vested interest (stock prices, funding, etc.) in being seen at the front of the pack. While many companies have said their results are promising, most of their vaccines aren’t being examined in peer-reviewed studies. Essentially, the world is just supposed to take their word for it until the data gets released.

After the developer has enough data from two large-scale vaccine trials where up to thousands of people are tested, they have to go through a number of other steps — such as filing a marketing application, obtaining licensing for manufacturing and transportation, and undergoing inspections of the facility where the vaccine is manufactured — before the FDA approves their vaccine for distribution.

The 17 entities below have already started or received approval to begin testing their vaccine candidates on humans.

Oxford University/AstraZeneca

County: United Kingdom

Trial stage: Phase III

In April, one of the biggest global pharmaceutical companies signed an agreement with the oldest university in the predominantly English-speaking world to develop a vaccine. The type of vaccine being tested has never been approved for use in humans before, but AstraZeneca’s CEO told a Belgian radio station last month that the company believes it would protect the user from coronavirus for up to a year.

The company started enrolling participants for its Phase II/III trials in May, while the Phase III U.S. trial will begin in August, according to the National Institute for Allergy and Infectious Diseases.

In late June, AstraZeneca reached a nine-figure deal with Brazil to produce tens of millions of doses beginning in August if it receives full regulatory approval, and the WHO’s chief scientist recently called the company the “leader” in the vaccine race.

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Screen grab taken from video issued by Britain's Oxford University, showing microbiologist Elisa Granato, being injected as part of the first human trials in the UK for a potential coronavirus vaccine, untaken by Oxford University, England, Thursday April 23, 2020. (Oxford University Pool via AP)

Sinopharm

Country: China

Trial stage: Phase III

China’s state-owned pharmaceutical company said its vaccine — developed by an institute based in Wuhan, where the virus was first discovered— “was found to have induced high-level antibodies in all inoculated people without serious adverse reaction,” after early results from a 1,120-person clinical trial conducted in April.

In June, Sinopharm became the first in the world to start Phase III trials in the United Arab Emirates.

The company has also reported positive results from animal trials and has said its facilities in Beijing and Wuhan will be able to produce a combined 220 million doses of the vaccine annually.

Moderna/National Institutes of Health

Country: U.S.

Trial stage: Phase II

In May, the Cambridge, Massachusetts-based firm announced positive results from its Phase I trial (about 8 patients) for its coronavirus vaccine, which is the novel mRNA variety. Phase II results haven’t been released yet, but the company had aimed to start its Phase III trial in July.

After STAT News reported on July 2 that the 30,000-person Phase III trial had been delayed, the company released a statement insisting the trial would still begin in July.

Prior to that, Dr. Anthony Fauci, the director of the National Institute for Allergy and Infectious Diseases, who serves on the Trump administration’s coronavirus task force, called the company’s early results “impressive,” and in late June, the WHO’s chief scientist said Moderna was “not far behind” AstraZeneca in the vaccine race.

But there’s a catch: Moderna’s history of delivering on its promises is shaky at best, and the company has been compared to Theranos, the notorious blood-testing company run by Elizabeth Holmes, for its practice of not publishing its scientific data for peer review.

CanSino/Beijing Institute of Biotechnology (Academy of Military Medical Sciences)

Country: China

Trial stage: Phase II

Working with a branch of the Chinese military, CanSino became the first company in the world to begin a clinical trial for a vaccine back in March, but the May results of its Phase I trial — the first peer-reviewed study completed for a vaccine — were mixed, particularly because older patients were less likely to develop neutralizing antibodies.

In June, however, CanSino got a surge of good news when the Chinese government authorized usage of the vaccine, which has only been through the first two phases of clinical trials so far. It’s the first coronavirus vaccine approved for use in any of the world’s armed forces, according to the South China Morning Post.

The approval means the vaccine can be used to try to stymie major outbreaks within the military. CanSino said the vaccine has gone through the first two phases of clinical trials so far, according to SCMP.

Novavax

Country: U.S.

Trial stage: Phase I/II

The Maryland-based company, which has secured hundreds of millions in funding from Bill Gates’ Coalition for Epidemic Preparedness Innovations, announced in May that it was beginning Phase I of human trials, with results expected in July.

Though Novovax is still in the early stages of testing, it’s already ramping up manufacturing. The company’s CEO told the Wall Street Journal that it hopes to produce 100 million doses this year and more than a billion next year.

Pfizer

Country: U.S. & Germany

Trial stage: Phase I/II

U.S. pharmaceutical giant Pfizer and German partner BioNTech are in the early stages of human clinical trials to develop an mRNA vaccine. In May, the company began testing four vaccine candidates on roughly 360 participants.

Pfizer CEO Albert Bourla told CNBC in May that the company expects to find out which vaccine performs the best in June or July and hopes to launch a trial with thousands of participants in September, with the hopes of delivering “millions of vaccines in the October timeframe.”

In early July, the company released a promising study from one of its vaccines, which had been tested on 45 participants.

“It’s the first positive data I’ve seen coming out of Operation Warp Speed,” Baylor College of Medicine’s Peter Jay Hotez told the Washington Post. “I’m really happy Pfizer took the initiative to publish it, whereas the others haven’t. I think we need to see more of this.”

Sinovac

Country: China

Trial stage: Phase I/II

Sinovac said in mid-June that 90% of its 600 volunteers in its Phase II trial showed an immune response to the virus. One of the company’s executives claimed in June that the developer could wrap up trials by the fall.

One local approval is obtained, the company’s Phase III trial is set to run on 9,000 volunteers at 12 sites in Brazil, which has seen the worst coronavirus rates in the world outside of the United States.

Imperial College London

Country: United Kingdom

Trial stage: Phase I/II

This vaccine candidate began a trial on about 300 people in the United Kingdom last week, with an mRNA vaccine similar to the one pursued by Pfizer and Moderna.

"We've been able to produce a vaccine from scratch and take it to human trials in just a few months,” Professor Robin Shattock told the BBC. "If our approach works and the vaccine provides effective protection against disease, it could revolutionise how we respond to disease outbreaks in the future."

Inovio

Country: U.S.

Trial stage: Phase I

The Pennsylvania-based company entered the clinical trial stage in April and has said it hopes to enter Phases II and III later this summer. A study released by the company showed that all but two of the 36 participants from Phase I had an immune response, but the results haven’t been examined in a peer-reviewed study.

The company had identified a coronavirus vaccine just three hours after it received access to the genetic sequencing in January, according to Inovio’s CEO Joseph Kim. But the company later admitted it had created a vaccine construct (essentially a precursor) and not a complete vaccine. After the company’s stock tanked, a class of shareholders sued in March.

Notably, the company has never brought a product to market in its nearly four decades of existence.

1593785681785-AP_20063753840024

Inovio Pharmaceuticals CEO Dr. J. Joseph Kim attends a meeting with President Donald Trump, members of the Coronavirus Task Force, and pharmaceutical executives in the Cabinet Room of the White House, Monday, March 2, 2020, in Washington. (AP Photo/Andrew Harnik)

Institute of Medical Biology at the Chinese Academy of Medical Sciences

Country: China

Trial stage: Phase I

Not much is known about the Institute of Medical Biology’s vaccine candidate except that it has reportedly moved into Phase II testing. The institute is, however, the country’s “largest production and research base” for the polio vaccine, according to the Chinese Academy of Sciences.

Genexine Consortium

Country: South Korea

Trial stage: Phase I

Genexine recently said it’s moving into a Phase I trial for its DNA-based vaccine, which is the first that’s been approved for testing by the South Korean government, according to BioWorld.com.

If Phase I goes well, Phase II is set to begin in the second half of the year in multiple countries.

Gamaleya Research Institute

Country: Russia

Trial stage: Phase I

Gamaleya is perhaps best known in the vaccine race because the head of the institute injected himself with the potential vaccine, a move that was met with mixed reactions in Russia and among the scientific community.

But in mid-June, the vaccine began trials in liquid and powder-based forms on about 38 human participants each.

Clover Biopharmaceuticals

Country: China

Trial stage: Phase I

The China-based company is collaborating with both U.K.-based GlaxoSmithKline and California-based Dynavax Technologies in trying to find a vaccine. Phase I human trials began in Australia in June, with results expected in July.

Anhui Zhifei Longcom

Country: China

Trial stage: Phase I

The Chinese government approved Zhifei’s vaccine candidate for testing in June, but little else is known about the company’s coronavirus vaccine effort thus far.

CureVac

Country: Germany

Trial stage: Phase I

The German government recently invested $338 million (300 million euros), or a 23% stake, into this company, which was once rumored to be in talks to be sold to the United States. The company said it wanted to start Phase I trials in June but hasn’t given any updates since the end of the month.

In early July, Tesla CEO Elon Musk said that his company was working with “CureVac and possibly others” on the vaccine race “as a side project.”

People’s Liberation Army Academy of Medical Sciences/Walvax

Country: China

Trial stage: Phase I

The military-run research institute got approval from the Chinese government on June 19 to begin human trials of its mRNA vaccine, becoming the eighth Chinese-developed vaccine to reach clinical trials.

Vaxine

Country: Australia

Trial stage: Phase I

The first Australian-developed candidate to reach human trials, Vaxine began a Phase I trial in early July in Adelaide. The trial will test 40 healthy candidates and results are expected in six to eight weeks, according to the Australian Financial Review.

"From there we will look to commence phase II and III trials straight away,” the company’s chairman told the paper. “The follow-on trials will need to go broader into the elderly and people with chronic disease, because they’re the most vulnerable to COVID infection.”

Cover: Unprecedented efforts from hundreds of laboratories around the world could help find a vaccine against Covid-19 before the end of the year, pharmaceutical industry leaders hope. (Sipa via AP Images)