Nov. 18 (Reuters) — Pfizer Inc. will seek emergency U.S. approval for its COVID-19 vaccine within days after final trial results showed its shot had a 95% success rate and no serious side effects, the drugmaker said on Wednesday.
The efficacy of the vaccine, which could start being distributed in December, was found to be consistent across different ages and ethnicities — a promising sign given the disease has disproportionately affected the elderly and certain groups including Black people.
The success rate of the vaccine developed by Pfizer and its German partner BioNTech is the highest of any candidate in late-stage clinical trials so far, and experts said it was a significant achievement in the race to end the pandemic.
Pfizer said 170 volunteers in its trial involving over 43,000 people contracted COVID-19 but 162 of them had only been given a placebo, meaning the vaccine was 95% effective. Of the 10 people who had severe COVID-19, one had received the vaccine.
"A first in the history of mankind: less than a year from the sequence of the virus to the large-scale clinical trial of a vaccine, moreover based on a whole new technique," said Enrico Bucci, biologist at Temple University in Philadelphia. "Today is a special day."
American drugmaker Pfizer said it would apply for the emergency authorization "within days" and expected the U.S. Food and Drug Administration's vaccine advisory committee to discuss the data in a public meeting, likely to be held in December.
The FDA committee tentatively plans to meet on Dec. 8-10, a source familiar with the situation said, though the dates could still change. The FDA did not respond to requests for comment.
The final trial analysis comes a week after initial results showed the vaccine was more than 90% effective. Moderna Inc. on Monday released preliminary data for its vaccine, showing 94.5% effectiveness.
The better-than-expected results from the two vaccines, both developed with new messenger RNA (mRNA) technology, have raised hopes for an end to a pandemic that has killed more than 1.3 million people and wreaked havoc upon economies and daily life.
The Pfizer-BioNTech shot was found to have 94% efficacy in people over 65 years, which experts said was crucial.
"This is the evidence we needed to ensure that the most vulnerable people are protected," said Andrew Hill, senior visiting research fellow at the University of Liverpool's department of pharmacology.
Global shares rose on Wednesday as the trial results countered concerns around the stubbornly high global infection rate. Pfizer shares were up 1.2% while BioNTech jumped 4.7% in the United States. By contrast, Moderna dropped 4.1%.
Investors have treated vaccine development as a race between companies, although there is likely to be global demand for as much vaccine as can be produced for the foreseeable future.
Fatigue and headaches
While some groups such as healthcare workers will be prioritized in the United States and Britain for vaccinations this year, it will be months before large-scale rollouts begin in either country.
Pfizer also has agreements with the European Union, Germany and Japan where distribution could begin next year.
Distribution of a shot is complicated by the need to store it at ultra-cold temperatures of -70 degrees Celsius. It can, however, be kept in a normal fridge for up to five days, or up to 15 days in a thermal shipping box.
Moderna's vaccine can be stored for up to six months at -20C though it is expected to be stable for 30 days at normal fridge temperatures of 2 to 8 degrees Celsius (36°-46°F).
Pfizer said its two-dose vaccine, called BNT162b2, was well-tolerated and that side effects were mostly mild to moderate, and cleared up quickly.
It said the only severe adverse events experienced by volunteers were fatigue and headaches. Out of 8,000 participants, 2% had headaches after the second dose while 3.8% experienced fatigue. Older adults tended to report fewer and milder adverse events.
"These are extraordinary results, and the safety data look good," said David Spiegelhalter, a professor and expert in risk and evidence communication at the University of Cambridge.
"It would be interesting to see what adverse reactions were reported by the group getting the placebo, since that gives an idea of how much of the adverse effects are due to the vaccination process, and how much is due to the vaccine itself."
For its trial, Moderna named five severe side effects experienced by at least 2% of those who received its shot: fatigue at 9.7%, muscle pain at 8.9%, joint pain at 5.2%, headache at 4.5%, pain at 4.1% and redness around the injection site at 2%.
Millions of doses
Authorization of vaccines for children will take longer. Only Pfizer has started vaccinating volunteers under the age of 18 in trials, giving shots to children as young as 12. Moderna and Johnson & Johnson have said they hope to start testing the vaccine in younger patients soon.
Pfizer's final results come as the virus is running rampant around the world, placing an enormous strain on healthcare systems with record numbers of new cases and hospitalizations.
The approach of winter in the northern hemisphere in tandem with the holiday season is expected to worsen case numbers as people spend more time indoors and have family gatherings.
Pfizer and BioNTech also said they plan to submit the data to other regulatory agencies around the world and submit data from the study to a peer-reviewed scientific journal.
Pfizer reiterated that it expects to make as many as 50 million vaccine doses this year, enough to protect 25 million people, and then produce up to 1.3 billion doses in 2021.
Of the dozens of drugmakers and research groups racing to develop vaccines against COVID-19, the next data release will likely be from AstraZeneca Plc with the University of Oxford in November or December. Johnson & Johnson says it is on track to deliver data this year.
(Reporting by Michael Erman in Maplewood, N.J.; Additional reporting by Ankur Banerjee in Bengaluru, Caroline Humer in New York, Dan Levine in San Francisco, and Elizabeth Howcroft and Kate Kelland in London and Emilio Parodi in Milan; Writing by David Clarke; Editing by Pravin Char)