With biotech company Moderna on Monday becoming the second U.S. drugmaker after Pfizer to announce strong data from clinical trials for its experimental COVID-19 vaccine, some Americans could be immunized as soon as the second half of December.
Moderna's announcement that its vaccine was 94.5 percent effective came a week after pharmaceutical company Pfizer and German technology firm BioNTech said an analysis found their vaccine was more than 90 percent effective.
Moderna and Pfizer said they intend to file in the coming weeks with the U.S. Food and Drug Administration (FDA) for emergency use of their vaccines, raising the prospect of at least two approved vaccines before the end of the year.
"These are obviously very exciting results," Dr Anthony Fauci, the nation's top infectious diseases doctor, said about Moderna's vaccine. "It's just as good as it gets 94.5 percent is truly outstanding.
"So now we have two vaccines that are really quite effective," Fauci said Monday on NBC's Today show. "So I think this is a really strong step forward to where we want to be about getting control of this outbreak."
On Monday, President-elect Joe Biden warned that President Donald Trump's refusal to accept the results of the Nov 3 presidential election could hamper the incoming administration's ability to rapidly distribute a vaccine.
"More people may die if we don't coordinate," Biden told reporters Monday in Delaware, in a news conference after he met with labor and business leaders and delivered a speech on the economy.
Nationwide, more than 11 million people in the U.S. have been infected with the coronavirus, and more than 246,000 have died, according to data reported Monday by Johns Hopkins University.
Fauci said he expects the first COVID-19 vaccinations to begin "towards the latter part of December, rather than the early part of December".
"I think that everybody else will start to get vaccinated towards the end of April," Fauci said. "And that will go into May, June, July. It will take a couple of months to do."
Healthcare workers, the elderly, and people with underlying medical conditions will get the vaccine first.
Moderna said Monday that it expects to be able to ship about 20 million vaccine doses in the U.S. by year-end. Next year, the company said it expects to be able to make 500 million to 1 billion doses worldwide.
Both vaccines are given in two doses several weeks apart, but there are major differences in how the vaccines are stored.
Moderna's vaccine requires long-term storage at -20 C (-4 F) and is stable for 30 days between 2 to 8 C (36 to 46 F).
Pfizer and BioNTech's vaccine, however, requires some of the coldest temperatures of any vaccine under consideration: -70 C (-94 F) or lower.
Moderna's vaccine can be thawed and kept in a normal refrigerator for 30 days. Pfizer's vaccine can survive in a normal refrigerator for five days.
Pfizer said last week that it is developing a powder form of the vaccine. Powdered vaccines are often reconstituted with a liquid and then injected. The new powder vaccine would reportedly work for standard refrigeration temperatures and could be ready in 2021, the company said.
Fauci's agency, the National Institute of Allergy and Infectious Diseases, collaborated with Cambridge, Massachusetts-based Moderna on the development of the vaccine. In July, it said it expected to spend about $410 million on the effort.
The federal Operation Warp Speed project to hasten development of COVID-19 vaccines awarded Moderna a $1.5 billion contract in August to ramp up manufacturing and deliver 100 million vaccine doses, enough for 50 million people. The government has an option to buy up to 400 million more doses.
"It was one of the greatest moments in my life and my career. It is absolutely amazing to be able to develop this vaccine and see the ability to prevent symptomatic disease with such high efficacy," said Dr Tal Zacks, Moderna's chief medical officer, of learning the results.
Among those praising Moderna was Pfizer CEO Albert Bourla, who said in a Twitter post that he was "thrilled to hear the good news".
According to Moderna, side effects seen from its vaccine at the interim analysis included pain at the injection site, and aching muscles and joints, which self-resolved within days. The data safety and monitoring board said it didn't identify "any significant safety concerns".
Pfizer's and Moderna's vaccines have similar results because they use the same technique to activate the body's immune system.
The vaccines deliver messenger RNA, or mRNA, which is a genetic recipe for making the spikes that sit atop the coronavirus. Once injected, the body's immune system makes antibodies to the spikes. If a vaccinated person is later exposed to the coronavirus, those antibodies should stand at the ready to attack the virus. No vaccine currently on the market uses mRNA.
"There has always been skepticism about mRNA it's brand new and would it work?" Fauci said. "What we saw in the trials is there was no real safety concern, and the efficacy is quite impressive. We saw nearly identical results (with Pfizer and Moderna) and it almost really validates the mRNA platform."
The latest vaccine news buoyed the U.S. stock market Monday, as Moderna shares closed up 9.6 percent. The Dow Jones Industrial Average finished up 471 points, about 50 points below the 30,000 mark, a level it hasn't crossed in its history.