An experimental coronavirus vaccine made by modern biotech company elicited a promising immune response against the virus and appeared safe in the first 45 people who received it, researchers reported Tuesday in The New England Journal of Medicine.
© Ted S. Warren / Associated Press
The 45 people who were vaccinated in the early stage of the Moderna vaccine test produced neutralizing antibodies against the coronavirus, an encouraging sign.
The Moderna vaccine, developed with researchers from the National Institute of Allergy and Infectious Diseases, was the first coronavirus vaccine to be tested in humans, and the company announced Tuesday that Phase 3 testing would begin on July 27, involving 30,000 persons. Half of the participants will be a control group that will receive placebos.
This large clinical trial is expected to be completed in late October. But it is unclear whether it will be possible to demonstrate that the vaccine is safe and effective by then. The trial should show that those who were vaccinated were significantly less likely to contract the virus than those who received a placebo. The fastest way to get results is to test the vaccine in a “hot spot” with many cases, and the study looks for people at high risk because of their location or circumstances.
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Vaccines and improved treatments are the only hope that lives will be back to normal, and dozens of companies are competing to develop vaccines. Experts agree that more than one vaccine will be needed, because no company could produce the billions of doses needed.
“None of us is safe unless we are all safe,” said Dr. Angela Rasmussen, a virologist at Columbia University in New York. “It is not just us. They are all in the world. “
The Modern vaccine uses genetic material from the virus, called mRNA, to stimulate the immune system to fight the coronavirus.
Tuesday’s report confirmed and provided details about the findings the company announced on May 18 in a press release that was criticized for the lack of data. Moderna defended itself at the time and said that, as a publicly traded company, it had a legal obligation to disclose results that could affect its share price, and that the actual data would be published later.
The results come from an initial Phase 1 study that was designed to test low, medium, and high doses of the vaccine and to assess its safety and ability to create immunity to the virus. Participants were 45 healthy adults, ages 18 to 55, who received two vaccines 28 days apart.
After the second injection, all participants developed so-called neutralizing antibodies, which can inactivate the virus in laboratory tests. The levels of these antibodies were similar to those in the higher range in patients who had recovered from coronavirus infections. The vaccine also produced a favorable response involving T cells, another part of the immune system.
“It exceeds all expectations,” said Dr. Kizzmekia S. Corbett, a viral immunologist and team leader who developed the vaccine at the Institute for Infectious Diseases.
More than half of the participants had side effects, such as fatigue, chills, headaches, muscle aches, and pain at the injection site. Some had a fever. One person who received the low dose developed hives and was withdrawn from the study. None of the side effects was considered serious.
Experts who were not involved in the study said the results were encouraging, but early. “Just because you have antibodies doesn’t mean you’re completely immune,” said Dr. Rasmussen.
It is possible, he said, that a vaccine does not completely prevent infection, but that the disease is less severe. “If it’s about choosing between a bad cold and being on a fan, I’m going to take the cold,” she said.
Dr Paul Offit, an infectious disease expert at the University of Pennsylvania and the Children’s Hospital of Philadelphia, said that neutralizing antibodies and other immune responses were a good sign, but that it was not yet known whether they would actually protect people against the virus. , or how long they would last. The side effects were a “small price to pay” for protection against a potentially serious illness, he said, although fever may be a cause for concern once the vaccine is administered to large numbers of people.
“You are always concerned that fever, especially high fever, may lead to other things,” Dr. Offit said, adding that only a large controlled study can determine if the vaccine is truly safe and effective.
Otherwise, “you are reading the tea leaves,” he said. “You just don’t know anything until you do a Phase 3 test.”
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