US biotech firm Moderna said Tuesday it would enter the final stage of human testing for its COVID-19 vaccine on July 27, after promising results were published in an influential magazine.
The Phase 3 trial will recruit 30,000 participants in the US, half to receive the vaccine at dose levels of 100 micrograms and the other half to receive a placebo.
It is designed to show whether the vaccine is safe and can prevent infection with the SARS-CoV-2 virus, or, if people are still infected, whether it can prevent infection from progressing to symptoms.
If they have symptoms, the vaccine can still be considered a success if it stops severe cases of COVID-19.
The study should run until October 27, according to its page at clinictrials.gov.
The announcement came after New England Journal of Medicine On Tuesday it published the results of the first stage of the Modern vaccine trial, which showed that the first 45 participants developed antibodies against the virus.
Moderna, currently in the intermediate stage, is considered to be in a leading position in the global race to find a vaccine against the coronavirus, which has infected more than 13.2 million people and killed 570,000.
SinoVac from China is also in Phase 2.
Russia’s TASS news agency announced Sunday that Russian researchers have completed clinical trials with a vaccine, although they have not shared their data.
Scientists caution that the first vaccines to hit the market may not be the most effective or safest.
‘Encouraging’ results
Moderna had previously released “provisional results” from the early stages of its test, called Phase 1, in a press release on its website in May.
These revealed that the vaccine had generated immune responses in eight patients, a result called “encouraging” by Anthony Fauci, director of the US National Institute of Allergy and Infectious Diseases, which is jointly developing the vaccine.
But some in the scientific community said they would reserve judgment until they saw the full results in a peer-reviewed way.
According to the new document, 45 participants were divided into three groups of 15 each to test doses of 25 micrograms, 100 micrograms, and 250 micrograms.
They were given a second dose of the same amount 28 days later.
After the first round, antibody levels were found to be higher with higher doses.
After the second round, participants had higher levels of antibodies than most patients who had had COVID-19 and had generated their own antibodies.
More than half of the participants experienced mild or moderate side effects, which is considered normal.
Side effects included fatigue, chills, headache, body aches, and injection site pain.
Three participants did not receive their second dose.
They included one who developed a rash on both legs, and two who missed the window because they had COVID-19 symptoms, but their tests later came back negative.
“The results seem pretty good and pretty consistent,” David Lo, a biomedical science professor at the University of California Riverside, told AFP.
However, he cautioned that more work was needed to assess the vaccine’s safety, including to make sure it wasn’t counterproductive by making the immune system “tolerant” to the actual virus.
Amesh Adalja, an infectious disease specialist at Johns Hopkins University, added that it was encouraging that participants developed high levels of an advanced class of antibodies.
However, he added: “You must be very limited in how much you can extrapolate from a phase one clinical trial because you want to see how this works when a person is exposed to the real virus.”
The Modern vaccine belongs to a new class of vaccine that uses genetic material, in the form of RNA, to encode the information necessary to grow the spike protein of the virus within the human body, to activate an immune response.
The spike protein is a part of the virus that it uses to invade human cells, but by itself the protein is relatively harmless.
The advantage of this technology is that it avoids the need to manufacture viral proteins in the laboratory, eliminating months of the standardization process and helping to increase mass production.
No vaccine based on this platform has previously received regulatory approval.
© Agence France-Presse
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