Mice who received more than four Covid vaccine jabs had a collapse in their ability to fight the coronavirus, Chinese researchers have found.
The damage extended past antibodies, the immune system’s front line of defense against viruses and bacteria, to the T-cells that form the crucial backup.
The researchers reported the finding in a peer-reviewed paper published December 22 in the journal iScience. In surprisingly clear language, they warned:
Our findings demonstrate potential risks with the continuous use of SARS-CoV-2 vaccine boosters, providing immediate implications [emphasis added] for the global COVID-19 vaccination enhancement strategies.
Later in the paper, the researchers were even more direct:
We found that the protective effects from the humoral immunity and cellular immunity established by the conventional immunization were both profoundly impaired during the extended vaccination course.
The finding has not been confirmed in humans.
But the mice the researchers used are genetically altered to model accurately the human response to the coronavirus and have “been shown to share profound similarities [emphasis added] with humans in response to SARS-CoV-2 infections,” as the paper explains.
The scientists used a vaccine that has a different mechanism of basic action than the mRNA jabs from Pfizer and Moderna, which turn our own cells into spike protein factories. But like them, the Chinese-tested vaccine causes the immune system to focus on a specific part of the coronavirus spike protein to the near-exclusion of other responses.
The finding may help to explain why large epidemiological studies keep finding that people who have received multiple boosters are at higher risk for Omicron infection than unvaccinated people.
(Highlights: Extended immunizations destroy the immune system’s ability to fight the coronavirus)