Numerous pharmaceutical companies are racing to complete clinical trials and become the first to successfully get U.S. approval for a vaccine to fight the coronavirus, which has infected more than 50.5 million people worldwide in 11 months.
A safe and effective vaccine is seen by investors and policymakers as a solution to get the global economy back on track after the pandemic wreaked havoc on nearly every country across the globe and upended businesses.
Phase three trials are the critical last step needed to get the vaccines submitted to the Food and Drug Administration for potential authorization and distribution. Of the 47 vaccines in clinical trials worldwide, there are currently four U.S.-backed frontrunners in phase three: Pfizer, Moderna, AstraZeneca and Johnson & Johnson's. A fifth drugmaker, Novavax, said it expects to begin its late-stage trial in the United States by the end of this month.
On Monday, Pfizer announced positive early results from its late-stage vaccine trial, saying its vaccine was more than 90% effective in preventing Covid-19 among volunteers who had no evidence of prior infection.
Pfizer's vaccine results are "very good news across the board," said Dr. Paul Offit, director of the Vaccine Education Center at Children's Hospital of Philadelphia. But he said he still would like to see how safe and effective the vaccine is in subgroups, including older people, African Americans and people with preexisting conditions.
Because of the pandemic, U.S. officials and drugmakers have been accelerating the development of vaccine candidates by investing in multiple stages of research even though doing so could be for naught if the vaccine ends up not being effective or safe. The U.S. has doled out billions to help develop a vaccine and secure doses if and when one is approved.
Pfizer and Moderna are slightly ahead of the other three companies and are seen as the likely companies to get the first approvals. Moderna announced last month that it had completed enrollment in its 30,000-person late-stage trial, and Pfizer is already delivering key results in its trial.
At the current pace of vaccine development, investors expect things to get back to "normal" by the middle or end of next year, Ronny Gal, a pharmaceutical analyst for Bernstein, said in a phone interview with CNBC. Some "pessimists" project a return to normal won't be until sometime in 2022, according to Bernstein biotech analyst Vincent Chen.
Wall Street analysts and infectious disease experts note there is never a guarantee as there is always a chance the vaccines in late-stage development may not be safe or effective. Analysts add that countries also still face logistical challenges such as setting up vaccine distribution sites and acquiring enough needles, syringes and bottles needed for immunizations.
Here is the status of the five frontrunners in the vaccine race:
Pfizer announced Monday that its coronavirus vaccine was more than 90% effective in preventing Covid-19 among those without evidence of prior infection. Comparatively, the CDC says a vaccine for influenza reduces the risk of flu illness by between 40% to 60% among the overall population.
It plans to submit an application for emergency use authorization with the FDA later this month. Investors were expecting to see the data in October, but Pfizer CEO Albert Bourla told CNBC last month that it was unlikely the company would have results ready before the U.S. election on Nov. 3.
The U.S.-based pharmaceutical giant has been working alongside German drugmaker BioNTech on the experimental vaccine. The vaccine contains genetic material called messenger RNA, or mRNA, which scientists hope provokes the immune system to fight the virus.
Pfizer announced on July 22 that the U.S. agreed to buy 100 million doses of its vaccine for up to $1.95 billion. The agreement, part of the Trump administration's vaccine program Operation Warp Speed, allows the U.S. to acquire an additional 500 million vaccine doses. Bourla said Monday the company is on track to produce up to 50 million vaccine doses in 2020, and up to 1.3 billion doses in 2021.
Moderna told investors on Oct. 29 that it was "actively preparing" for the global launch of its potential vaccine after completing enrollment in its 30,000-person trial a week earlier. About 37% of the people in the trial are from diverse communities, the company said.
Moderna CEO Stephane Bancel has said the company could see early results from its late-stage trial sometime in November. It expects to apply for emergency use authorization with the FDA in December, according to Bancel.
Like Pfizer, Moderna used mRNA technology to develop its vaccine.
The Cambridge, Massachusetts-based company already has supply agreements in North America, the Middle East and in other regions of the world. It announced in August that it had reached a deal with the U.S. government to supply 100 million doses of its vaccine. The deal gives the federal government the option to purchase up to 400 million additional doses. The U.S. had already invested $955 million in the vaccine development, bringing its total investment up to $2.48 billion, the company said at the time.
AstraZeneca said on Oct. 23 it was allowed to resume its U.S. trial testing its experimental vaccine after it had been on a regulatory hold by the FDA for over a month due to an unexplained illness in a patient in the United Kingdom.
It's unclear how the hold will impact its vaccine timeline. The hold meant that the company was unable to administer second doses of its two-dose vaccine regimen to participants in its 30,000 person U.S. trial. The company has previously said it could be ready to present data to the FDA for authorization by the end of the year.
AstraZeneca is developing the vaccine with the University of Oxford. The vaccine uses genetic material from the coronavirus with a modified adenovirus. In July, the company published data that showed its experimental vaccine produced a promising immune response in an early-stage trial and appeared to be well tolerated.
In May, the U.S. government said it reached a deal with AstraZeneca for at least 300 million doses of the vaccine for up to $1.2 billion.
Johnson & Johnson on Sept. 23 became the fourth drugmaker backed by the U.S. to enter late-stage testing for a potential vaccine.
On Oct. 12, the company announced its trial, which aims to enroll up to 60,000 adult volunteers, had been paused due to an unexplained illness. It was told by the data and safety monitoring board, which oversees clinical trials, that it could resume its trial about a week later.
J&J has previously said it anticipates possible vaccine batches for a potential emergency use authorization available in early 2021.
J&J's vaccine is a one-dose shot and was constructed using genetic material from the coronavirus and an uninfectious adenovirus. It uses similar technology as its Ebola vaccine. Preclinical studies have shown J&J's vaccine can generate a promising response in nonhuman primates and hamsters.
The U.S. government announced on Aug. 5 that it reached a deal with J&J for 100 million doses of its vaccine worth approximately $1 billion. The deal gives the federal government the option to order an additional 200 million doses, according to the announcement.
Novavax on Oct. 27 delayed the start of its late-stage trial in the U.S. by roughly a month to the end of November. It cited delays in scaling up the manufacturing process.
While it hasn't started its phase three trials in the U.S., it has begun a late-stage trial in the U.K. The company has said it expects it will have data needed for authorization as soon as the first quarter of 2021.
Novavax's vaccine contains synthesized pieces of the surface protein the coronavirus uses to infect humans. In August, the company announced that its potential vaccine generated a promising immune response in an early-stage clinical trial with 131 healthy participants.
In July, the U.S. government announced it had tapped the company to develop and manufacture the potential vaccine, with the aim of delivering 100 million doses by the beginning of next year. The U.S. said the deal was worth $1.6 billion.
–CNBC's Sam Meredith and Noah Higgins-Dunn contributed to this report.