In animal studies, mice received 1 or 2 injections of a variety of doses of the Moderna vaccine. (Reuters)
Chicago:
A series of studies on COVID-19 mice from Moderna Inc. have given assurances that it will not increase the risk of more serious disease and that a dose could provide protection against the new coronavirus, the data shows. preliminaries published on Friday.
Previous studies on a vaccine against SARS – a close cousin of the new virus that causes COVID-19 – suggest that vaccines against this type of virus may have the unintended effect of causing more serious illness when the vaccinated person is subsequently exposed to the pathogen, especially in individuals who do not produce a sufficiently strong immune response.
Scientists saw this risk as an obstacle to overcome before vaccines could be safely tested in thousands of healthy people.
Although data published by the National Institutes of Allergy and Infectious Disease (NIAID) and Moderna in the United States offer some assurance, the studies do not fully answer the question.
“This is the shortest start to the preliminary information,” said Dr. Gregory Poland, immunologist and vaccine researcher at the Mayo Clinic who saw the document, which has yet to be reviewed. by peers.
Poland said the document was incomplete, disorganized and the number of animals tested was small.
The authors stated that they submitted the work to a high-level review. Moderna’s vaccine is being tested mid-term in healthy volunteers. Moderna announced Thursday that it intends to begin final phase trials to recruit 30,000 people in July.
In animal studies, mice received one or two doses of a variety of doses of the Moderna vaccine, including doses deemed not strong enough to trigger a protective immune response. The researchers then exposed the mice to the virus.
Subsequent analyzes suggest that “underprotective” immune responses do not cause what is called improved vaccine-associated respiratory disease, sensitivity to more severe lung disease.
“The sub-protective doses did not prepare the mice for improved immunopathology after (exposure),” wrote Dr. Barney Graham of the Vaccine Research Center at NIAID and colleagues in the manuscript, published on the bioRxiv website.
Additional tests have suggested that the vaccine induces antibody responses to prevent the virus from infecting cells.
The vaccine also appeared to protect against coronavirus infection in the lungs and nose without evidence of toxic effects, the team wrote.
They noted that the mice that had received a single dose before exposure to the virus seven weeks later were “completely protected against viral replication in the lungs”, suggesting that a single vaccination prevented the virus from replicating in the lungs.
“At first glance, it seems promising to induce neutralizing antibody protection in mice,” said Dr. Peter Hotez, researcher at Baylor College of Medicine, in an email. He had not examined the document in detail.
Poland, which was not involved in the research, said the document excludes “important parameters” that could help scientists judge the work.
“The results, as presented, provide interesting data that are reassuring … It needs to be replicated and it needs to be peer reviewed,” he said.
(With the exception of the title, this story was not edited by GalacticGaming staff and is published from a syndicated feed.)
