A promising vaccine against covid-19 has proved 90% effective, protecting most people who get it, according to the drug maker Pfizer.
If the results hold up, it would mean a potential path out of the covid-19 crisis, which has shuttered business and schools across the world. However, supplies of the vaccine are likely to be limited until well into 2021, meaning most people won’t be able to get it anytime soon.
Pfizer’s trial, involving more than 40,000 people, is the first of a dozen large vaccine studies to yield results. “It is a great day for science, it is a great day for humanity. When you realize your vaccine has 90% effectiveness, that is overwhelming,” the company’s CEO, Albert Bourla, told CNBC. There is a now a “light at the end of the tunnel.”
According to the Wall Street Journal, the company believes it can seek authorization to sell the vaccine sometime this month, although regulators will have to review the data. Pfizer made the announcement in a press release and did not release the full data from the trial.
“The results are really quite good, I mean extraordinary,” Anthony Fauci, director of the National Institute of Allergy and Infectious Diseases, told the Washington Post.
The Pfizer vaccine, developed with a German firm, BioNTech, makes use of a new and largely untested strategy. While typical vaccines employ a weakened version of a virus, or part of it, the Pfizer vaccine consists of a shot of genetic information, in the form of RNA.
After this vaccine is injected, a person’s own cells proceed to use that genetic information to manufacture a portion of the virus, called the “spike protein,” setting off an immune response.
Because they work from the virus’s genetic code, the makers of RNA vaccines, including Moderna Pharmaceuticals, were first to quickly develop candidate shots last spring. Several companies received US funding to run large studies as part of Operation Warp Speed, but Pfizer, which ran its own trial separately, ended up outpacing the competition.
In July, Pfizer agreed to sell 100 million doses of its vaccine to the US government at a cost of $1.95 billion, or just below $20 a dose, if it is approved, and it has reached similar supply agreements with other countries. The US has the right to buy up to 600 million doses eventually.
One drawback of RNA vaccines is that they need to be kept at ultra-cold temperatures, complicating their distribution. They are also cumbersome to manufacture.
Pfizer said it would only have enough supply to vaccinate about 20 million people by the end of 2020. By the end of 2021, the company anticipates, there will be 1.3 billion doses—enough to vaccinate about 650 million people, considering each person gets two doses.
Countries are vying to be first to get vaccine supplies, and it’s unclear how Pfizer will distribute the first doses. The founder and CEO of BioNTech, Ugur Sahin, told the Financial Times that the companies would use “a fair approach” that could prioritize areas where regulators give formal approval to its shot.
During the trial, volunteers, none of whom had covid-19 previously, got either two doses of the vaccine or placebo shots. Then doctors waited to see who developed covid-19. According to the companies, 94 people have developed the disease during the trial so far.
The claim of 90% efficacy means nearly all these cases were among volunteers who received the placebo, a few who received the vaccine got sick too. “This is really a spectacular number,” Akiko Iwasaki, an immunologist at Yale University, told the New York Times
If Pfizer’s claim holds up, and no safety risks appear, it suggests coronavirus vaccines in general will prove a strongly potent countermeasure against the pandemic. By comparison, annual influenza vaccines prevent flu-like illness only about 50% of the time, according to the CDC.
During the fall, Pfizer and its CEO came under intense pressure not to announce positive results prematurely or rush to seek authorization of its vaccine before Election Day. That campaign was publicly led by doctors including Eric Topol, of the Scripps Research Institute, who say they feared the data could be politicized by the White House.
In the end, Pfizer opted to delay looking at its data, but that decision may have had its own political consequences. Given how strong Pfizer says its results are, it suggests the data would also have been positive in late October, when a positive news announcement could have affected voting in the presidential election between President Donald Trump and challenger Joe Biden.
Today, both men weighed in on the vaccine news with statements that showed dramatically different outlooks toward covid-19.
In a tweet, President Trump said, “STOCK MARKET UP BIG, VACCINE COMING SOON. REPORT 90% EFFECTIVE. SUCH GREAT NEWS!”
In his own statement, also posted to Twitter, President-elect Joe Biden congratulated the scientists involved but cautioned that “it will be many more months before there is a widespread vaccine in this country” and that people will have to continue to battle the virus using social distancing, hand washing, and wearing a mask.
“For the foreseeable future, a mask remains a more potent weapon against the virus than the vaccine,” Biden said.