USA: The two-dose Moderna vaccine fared well in Phase 3 clinical trials involving more than 30,000 adults, proving to be 94.5% effective at preventing COVID-19 in the roughly seven weeks after the second shot was administered.
The vaccine was created using the same type of technology as the one made by Pfizer and BioNTech, which was authorized late last week and has been administered to hundreds of thousands of Americans since Monday. But Moderna’s vaccine will be shipped to many more locations than Pfizer’s, in large part because it doesn’t require the same ultracold storage system.
Distribution of the Moderna shot could begin as soon as possible, according to officials overseeing Operation Warp Speed, the Trump administration initiative to accelerate the development and distribution of COVID-19 vaccines and medicines. With both options now available, up to 20 million people could receive their first dose by the end of the month, and up to 100 million could get it by the end of March, officials say.
“With the availability of two vaccines now for the prevention of COVID-19, the FDA has taken another crucial step in the fight against this global pandemic that is causing vast numbers of hospitalizations and deaths in the United States each day,” said FDA Commissioner Stephen M. Hahn as he announced the decision.
The emergency-use authorization for Moderna’s vaccine comes at a pivotal point in the pandemic, which has claimed more than 310,000 lives in the United States. A report published Thursday in the Journal of the American Medical Association called COVID-19 “the leading cause of death in the United States,” surpassing the toll of even heart disease and cancer.
Gatherings with family and friends over the Thanksgiving weekend have helped fuel an unprecedented surge in coronavirus infections, and Dr. Anthony Fauci, the nation’s top infectious disease expert, has warned that the situation will become even worse if Americans ignore experts’ pleas to stay home for Christmas and New Year’s.
This week, hospitals throughout Southern California and the San Joaquin Valley reported that all beds in their intensive care units were filled. The state is now logging hundreds of deaths each day, and the cumulative death toll of more than 22,000 surpasses that of all but 16 countries.
Considering the extent of the devastation, the emergency authorizations of COVID-19 vaccines are triggering “very mixed emotions,” said Dr. Shira Doron, an infectious disease physician and hospital epidemiologist at Tufts Medical Center who received the Pfizer vaccine Tuesday.
“For front-line staff, I’m thrilled — I’ve been seeing the fear in their eyes for months,” she said. Still, she added, the public “cannot lose sight of the fact that transmission is out of control right now. ... there's absolutely nothing to suggest we’re going to see relief anytime soon.”
About 6 million doses of the Moderna vaccine will be sent to more than 3,000 locations across the country, said Army Gen. Gus Perna, who is overseeing the distribution for Operation Warp Speed.
“There is not one part of this country that is not being touched,” Perna said.
Each state and U.S. territory is slated to receive an allotment based on the size of its population. Most states, in turn, have opted to prioritize health care workers and residents and staff of long-term care facilities for the first round of vaccinations.
The emergency-use authorization allows the vaccine to be used in adults ages 18 and up.
As with the Pfizer vaccine, millions of second doses of the Moderna vaccine are being held in reserve. They will be shipped out to states in two weeks.
The design of Moderna’s vaccine gives it a clear advantage over the one from Pfizer: Because it is more stable, it doesn’t need to be kept at a frigid minus-94 degrees Fahrenheit. Instead, it can be stored for six months at mere minus-4 degrees, and it can last 30 days at a balmy 36 to 46 degrees — a temperature that can be maintained by a regular refrigerator.
Like the Pfizer vaccine, the Moderna shots deliver molecules of messenger RNA into the body, providing cells with instructions for making a specific type of coronavirus protein. That protein, in turn, stimulates the immune system to make antibodies.
While the mRNA breaks down within days of the shot, the antibodies hang around, ready to defend against future exposures to the coronavirus.
In an analysis prepared by FDA scientists and reviewed by an independent advisory committee, just five of the 13,934 participants who received two doses of the vaccine developed COVID-19, compared with 90 people among the 13,883 who received placebo shots of simple saline. Based on those figures, the vaccine was 94.5% effective.
When the analysis was extended to include two more weeks of follow-up, there were 11 cases of COVID-19 in the vaccine group and 185 in the placebo group. That reduced the vaccine’s effectiveness to 94.1%.
None of the people who developed COVID-19 after receiving the vaccine had a severe case of the disease. In the extended analysis, there were 30 such cases among those who received the placebo.
In the main analysis, the vaccine was 100% effective in people ages 65 and up as well as among Black, Latino, Asian and multiracial clinical trial participants. It was 95.9% effective among people with health conditions that make them more susceptible to severe infection, including chronic lung disease, cardiac disease, obesity, and HIV.
The Moderna shot, like the Pfizer one, was slightly more effective in men than in women.
Members of the FDA advisory panel that met Thursday welcomed an early signal of an exciting possibility — that even a single dose of the Moderna vaccine might confer a meaningful level of protection. In the three weeks after receiving their first dose, study participants who got the vaccine were 69.5% less likely to show symptoms of COVID-19 than were those who got the placebo.
There were also hints that the Moderna vaccine might prevent people with mild or asymptomatic infections from spreading the virus to others. If that is confirmed in further studies in the coming months, the vaccine might help eliminate the “silent spreaders” who are believed to be responsible for about half of coronavirus transmissions.
The FDA didn’t find any significant safety issues with the Moderna vaccine, aside from common side effects such as fatigue and muscle aches. Those symptoms, while unpleasant, signal that the body is mounting an immune response that will serve it well in the case of a future coronavirus exposure.
One unusual side effect that the FDA might note in its prescribing information: facial swelling for people who have dermal fillers in their cheeks. At least two trial participants with a history of the cosmetic injections reported swelling, but their symptoms were resolved with a steroid or antihistamine treatment.
As the vaccination campaign expands to millions, scientists warn that a small number of more severe vaccine reactions could occur. That’s been the case with other vaccines, and a handful of people have had serious allergic reactions after receiving a first dose of the Pfizer product.
But experts say that the risk of developing a severe case of COVID-19 far outweighs the risk of a serious vaccine reaction and that these well-publicized anecdotes should not dissuade individuals who are eligible for the injection from getting it.
Indeed, once the vaccine rollout moves beyond health care workers and into the general population, the future of the pandemic will depend largely on the public’s willingness to get the shots. Epidemiologists estimate that 70% of the country will need to be vaccinated in order to achieve a level of herd immunity that might prevent the virus from spreading and allow for a safe return to normal life.
In addition to the Pfizer and Moderna injections, a third vaccine candidate developed by Janssen, a division of Johnson & Johnson, is also showing progress and could be ready for regulatory review and distribution as soon as February, said Dr. Moncef Slaoui, chief scientific adviser to Operation Warp Speed.
The Janssen vaccine requires only one shot instead of two. With the help of that product and others, Health and Human Services Secretary Alex Azar said he expects every American who wants a shot should be able to get one by the end of June.
©2020 Los Angeles Times
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