The news Monday that a second coronavirus vaccine has proven more than 90 percent effective in late-stage trials could be a game-changer, but the hard work isn’t over.
Governments and vaccine developers are still figuring out how to distribute limited early stocks of the shots, whether they can pump up production to meet intense global demand, and — at least in the United States — how to overcome a rising tide of vaccine hesitancy.
Still, experts said those are good problems to have less than a year after the start of the deadly global pandemic. The fastest shot ever developed, for mumps, took four years from conception to approval.
Barring any last-minute safety or efficacy concerns, vaccine developers Moderna and Pfizer plan to seek emergency-use authorization this month from the Food and Drug Administration. The federal government is betting that vaccination will begin as early as December.
“I don’t want to get ahead of the FDA, but the data are striking,” the government’s top infectious disease expert, Anthony Fauci, said Monday morning on NBC’s “Today” show, hours after Moderna revealed that its vaccine was more than 94 percent effective.
“Now we have two vaccines that are really quite effective,” added Fauci, whose institute at the NIH helped to develop and test the Moderna shot. “This is a really strong step forward to where we want to be, about getting control of this outbreak.”
At least two other vaccines, developed by Johnson & Johnson and AstraZeneca, are also in late-stage trials and could deliver results this year.
Moderna’s announcement, and Pfizer’s news last week that its vaccine is more than 90 percent effective, comes during the darkest period yet of the U.S. coronavirus epidemic. The country is now reporting more than a million new cases a week, crowding hospitals across the country. Nearly 250,000 people have died. And the surge shows no signs of slowing.
The results are better than expected.
Moderna’s initial findings from its 30,000-person, Phase III trial have not yet been peer-reviewed or published in a scientific journal. But researchers said the results suggested that the vaccine was highly effective and safe.
"We should be celebrating. This is a big win for science," said Akiko Iwasaki, an immunobiologist at Yale University.
An analysis of the first 95 trial participants to contract the virus revealed that the vast majority — 90 people — had received a placebo, while five had received the Moderna vaccine. That amounts to a 94.5 percent efficacy rate, better than most scientists had expected for a first-generation coronavirus shot.
All 11 of the severe Covid-19 cases have occurred in placebo recipients, Moderna CEO Stéphane Bancel told reporters Friday.
Most side effects reported by trial participants have been mild or moderate and short-lived, Moderna said. The most common severe reactions have included fatigue, headaches and pain at the injection site.
Pfizer and its German partner BioNTech, did not include detailed information on severe cases or side effects among participants in their vaccine trial when they released preliminary results last week. But the partners said they had not received reports of any “serious safety concerns.”
Early data from both Moderna and Pfizer are promising, but “we want to see more detailed data, and the real review” will happen when the companies present their trials results to the FDA’s coronavirus vaccine advisory committee, said Saad Omer, director of the Yale Institute for Global Health.
Both vaccines rely on the same messenger RNA technology, which has never been used to bring a shot to market. The approach relies on injecting the genetic material, known as mRNA, into the body, where it enters cells and begins to pump out copies of the coronavirus’ spike protein. That prompts the immune system to churn out antibodies against the virus.
Will they work for everyone? Stay tuned.
Moderna made a point to enroll people older than 65 years old, whose immune systems are generally weaker than those of younger adults and children, and people with chronic health conditions that raise their risk for severe Covid-19 infection. Those volunteers — 42 percent of the total — could provide a window into how well the shot works in people with diminished immune systems, diabetes, heart problems and obesity.
Pfizer also enrolled older people and so far is the only vaccine-maker in U.S. trials to study its shot in children as young as 12 years old.
Both manufacturers recruited from Black and Latinx communities hit disproportionately hard by the virus but historically underserved by the medical system.
But researchers still do not know how long either shot protects against the coronavirus. Manufacturers still need to follow at least half of their volunteers for two months before they can file for emergency use; each will continue tracking patients’ immunity for months and years after the trial.
And vaccines, although potentially the most powerful tools available to fight the virus, won’t eliminate it immediately. “There will be a substantial period where you’ll need social-distancing measures,” even with effective vaccines, Omer said.
Vaccination could start in December.
Both Pfizer and Moderna still need to collect a couple more weeks worth of safety data to meet the FDA’s standard for an emergency authorization. Barring any surprises in the FDA’s review, the agency could provide emergency authorizations for both vaccines in mid-December.
The government’s vaccine accelerator, Operation Warp Speed, plans to begin distributing any vaccines within 24 hours after the FDA authorizes them.
But public health experts, elected officials from both parties and members of President-elect Joe Biden’s transition team have warned that President Donald Trump’s refusal to concede could hamper the coronavirus response.
Trump so far has prevented the General Services Administration from recognizing Biden as president-elect, cutting off the transition team’s access to crucial data on the nation’s coronavirus response.
“We want to get doses to people starting in December. We want to really get the ball rolling as we get into January, February and March,” he said. “And the way you do that is by essentially having the two groups speak to each other and exchange information.”
Closing the freezer gap
Unlike the Pfizer vaccine, which requires ultra-cold storage from shipment to vaccination, Moderna’s vaccine can be kept in a refrigerator for up to 30 days and at room temperature for up to 12 hours.
“The ability to store our vaccine for up to 6 months at -20° C” — or -4 degrees Fahrenheit — “including up to 30 days at normal refrigerator conditions after thawing is an important development and would enable simpler distribution and more flexibility,” said Juan Andres, chief technical operations and quality officer at Moderna.
Moderna also said that its vaccine will not require on-site dilution or special handling, allowing its use at pharmacies and physicians’ offices.
By contrast, Pfizer’s vaccine must be stored at -94 degrees Fahrenheit, which requires special freezers or dry ice. The shot can only withstand normal refrigeration for up to 24 hours and room temperature for no more than two hours after thawing.
How much is available?
Two promising vaccine candidates landing at virtually the same time will increase initial supply. Moderna and Pfizer both aim to deliver at least 20 million doses apiece to the U.S. government this year.
Because each is a two-dose shot, that translates to 10 million people getting the Moderna vaccine and 10 million people getting the Pfizer vaccine in 2020 if the FDA authorizes their use in the coming weeks.
The government has not released a detailed plan for distributing the vaccine, but says that the first doses will go to high-priority groups such as the elderly, health care workers and others who are medically vulnerable.
Looking ahead, Moderna said that it can make 500 million to 1 billion doses next year, while Pfizer is betting it can make up to 1.3 billion.
Will people take the vaccines?
Americans have grown increasingly skeptical of coronavirus vaccines in recent months, in part over fears that Trump’s administration would rush shots into use for political gain.
Trump has alleged, without providing any evidence, that federal scientists and manufacturers are conspiring against him; meanwhile nearly half of Americans believe that he is pressuring FDA to deliver shots sooner, according to a recent POLITICO/Morning Consult poll.
NIH Director Francis Collins told reporters on a press call Monday that he is “optimistic that if we communicate this information well, maybe [people will] roll up their sleeves.”
“There’s been a lot of hesitancy around vaccines and we need to deal with that issue for wider coverage," Iwasaki said. "I hope that people understand the vaccines are safe and effective, I hope that the 90% efficacy data will convince some people.”
But medical mistrust is particularly high among communities of color historically abused by science and disproportionately impacted by coronavirus cases and deaths. The administration has not yet released a federal outreach plan to boost confidence.