Study says booster vaccine prevents severe cases 1:30
(CNN) --
Moderna announced Wednesday that the first participant received a dose in the company's Phase 2 clinical trial of a COVID-19 booster vaccine that is specific for the omicron variant.
Moderna advances the trial into its next phase, as research published Wednesday in the
New England Journal of Medicine
found that a booster dose of the vaccine was still durable against the omicron variant, but showed signs of diminishing protection against the omicron variant. the antibodies.
"We are reassured by the persistence of antibodies to omicron six months after the currently licensed 50 μg mRNA-1273 booster dose. However, given the long-term threat demonstrated by immune escape of omicron, we are making progress in our omicron-specific booster vaccine candidate and we are pleased to start this part of our phase 2 study," CEO Stéphane Bancel said in a press release.
"We are also evaluating whether to include this specific omicron candidate in our multivalent booster program."
The CEO of Pfizer hopes that the vaccine against covid-19 will be applied annually, instead of frequent reinforcements
Moderna said it hopes to enroll about 600 people in the study, which will take place at up to 24 sites in the United States.
Some participants will already have two doses of the Moderna vaccine, and others will have a booster shot.
Moderna promises to share trial data with public health officials so they can make evidence-based decisions about the best COVID-19 booster strategy going forward.
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Pfizer and BioNTech, makers of the other main mRNA vaccine against covid-19, announced Tuesday that they have started their own trials of specific vaccines against omicron.
Study: After Moderna Booster, Antibodies Remain Durable Against Omicron, Though Declining
Omicron currently accounts for 99.9% of covid-19 infections in the US, the Centers for Disease Control and Prevention (CDC) reported Tuesday.
The delta variant accounts for the remaining 0.1%.
The new study claims that Moderna's COVID-19 booster vaccine remains durable against the omicron variant, but antibody protection declines to six times less six months after receiving the booster.
The study also found that neutralizing antibody levels declined against omicron much more rapidly than against the dominant variant of the virus that was circulating two years ago.
Research teams from Moderna, Duke University, Emory University, the Fred Hutchinson Cancer Research Center, Baylor College of Medicine, the University of Maryland School of Medicine and the National Institutes of Health examined samples of blood from people who had received Moderna's covid-19 vaccine.
Two doses of the vaccine produced detectable neutralizing antibodies against the omicron variant in 85% of people one month after the second dose, but, after seven months, neutralization against the variant was only detected in 55% of people .
Administration of a third booster dose of 50 micrograms (μg) of vaccine resulted in a 20-fold increase in neutralizing levels of Omicron within four weeks of booster administration, but after six months, those levels were reduced 6.3 times.
By comparison, the durability of neutralization against the ancestral strain of the coronavirus only increased 2.3-fold after six months.
"Although the antibody levels of the boosted study participants continued to exhibit strong neutralizing activity, the levels of these antibodies declined more rapidly for Omicron than for the first circulating SARS-CoV-2 virus." two years," the researchers said in a news release.
CDC supports FDA's decision to reduce the time between the first doses and the covid-19 vaccine booster
"There is immunological memory"
The study had some limitations.
It included a small sample size, so it may not fully reflect how well the vaccine neutralizes the virus in various populations or at different times before a person gets a booster.
In addition, these are not studies carried out in daily life, and the scientists only looked at the antibodies generated in the blood.
However, studies indicate that antibody levels correlate with real-world protection.
Study co-author Dave Montefiori, a professor in the Duke University Department of Surgery, said the drop in antibodies after the booster dose is very similar to the drop in antibodies with the delta variant that was seen six months after the booster. second dose of the vaccine, which prompted the appearance of booster doses.
"This is not uncommon for mRNA vaccines or vaccines in general," Montefiori said.
"Antibodies go down because the body realizes it doesn't need to keep them at such a high level. This doesn't mean there's no protection. There's immunological memory."
Montefiori said the concern is that the virus could change enough that the vaccine needs to be modified, pointing to Moderna's omicron-specific booster trial.
But for now, he said, the data isn't there yet, and the vaccines "are still working, and the booster is helping it work better, even against omicron."
optimism and caution
Dr. William Schaffner, medical director of the National Foundation for Infectious Diseases and a professor of medicine at Vanderbilt University, was cautiously optimistic about the results.
"The good news is that Moderna, when boosted, gives very high levels of antibodies, and of course that's very encouraging," said Schaffner, who was not involved in the new study.
"But as we've learned with these Covid viruses, antibody levels start to decline after a period of about six months."
We've seen it before, Schaffner said, but we don't know exactly how this translates to real-world performance.
"Whether this translates into less protection, particularly for severe disease, is not clear," he noted.
Booster shots provide the best protection against omicron, according to three large CDC studies
Data from large populations show that two doses of the vaccine plus a booster provide robust protection against severe disease, even against the omicron variant.
"I think this study reinforces that basically what was seen with the Pfizer vaccine plus the booster is replicated with Moderna as well, and it may also be a harbinger or an early sign that somewhere along the way, when we get through this pandemic and we come to a truce with this virus, we may need to do a periodic booster to maintain protection."
booster dosevaccine against covid-19