Repeated mRNA Vaccination May Hamper Recovery From COVID-19: Study

Five doses of Pfizer's Covid-19 vaccine that received emergency use authorization are ready for distribution at George Washington University Hospital in Washington on Dec. 14, 2020. JACQUELYN MARTIN/POOL/AFP via Getty Images

Taking multiple mRNA vaccines can end up raising the levels of a specific antibody that is linked to a reduced capacity of the immune system and “poor clinical outcomes of COVID-19,” according to recent research.

The preprint study, published in MedRxiv on Jan. 18, looked at the effects of Moderna and Pfizer mRNA COVID-19 vaccines as well as Novavax COVID-19 shots on IgG4 antibody levels in the human body.

IgG4 is a subclass of Immunoglobulin G (IgG) antibodies, which are proteins released by the immune system to fight against foreign substances. There are four subclasses of IgG antibodies—IgG1, IgG2, IgG3, and IgG4. Out of these, IgG4 is the least prevalent, accounting for around 0 to 5 percent of total IgG.

The study said that repeated mRNA COVID-19 vaccination “has been associated with increases in the proportion of IgG4” that could restrict the body’s ability to counter the infection.

“Following repeated mRNA vaccination, IgG4 was observed to increase from 0.04 percent of total SARS-CoV-2 spike–specific IgG after two doses to 19.27 percent after three doses.”

“Increased concentrations of IgG4 have been associated with immunosuppression and poor clinical outcomes of COVID-19, and while generally regarded as anti-inflammatory, may contribute to some autoimmune disorders and inflammatory IgG4-related diseases,” researchers said.

The study looked at three groups of individuals. The first group received three doses of Moderna’s mRNA vaccine while the second took Pfizer’s mRNA shots. Both of them also got Novavax’s COVID-19 vaccine as the fourth dose. The third group received four doses of Novavax.

Novavax’s COVID-19 vaccine is different from Moderna’s and Pfizer’s as it is not mRNA. Instead, Novavax is a protein subunit vaccine that contains spike proteins.

It also contains an ingredient called an adjuvant that helps the immune system respond to the spike protein. As the immune system is trained to respond to the spike protein, it’s able to react swiftly when a person gets infected by COVID-19.

In contrast, mRNA vaccines teach the body’s cells to produce the spike protein that triggers the immune response and eventually the antibodies.

While repeated mRNA vaccinations triggered “much higher anti-S IgG4 levels (>75-fold),” injecting Novavax vaccine “does not appear to induce notable increases in IgG4, even after multiple exposures.”

Instead, Novavax “drove proportional increases in IgG3, perhaps the most potent SARS-CoV-2 neutralizing antibody subclass.”

The study found that anti-spike protein IgG3 levels were “markedly higher (>10-fold)” after three or four doses of the Novavax vaccine.

Researchers highlighted the importance of IgG3 by citing an analysis which stated that while IgG3 and another antibody called IgM made up only 12 percent of total immunoglobulin mass, they accounted for “approximately 80 percent of total live SARS-CoV-2 neutralizing activity.”

Funded by Novavax

The study was funded by Novavax. Two groups of samples were used in the study. One sample came from a clinical trial that had links to Novavax. Another sample was from a clinical trial funded by the company.

Out of the 15 researchers in the study, 11 were reported to be employees and stockholders at Novavax. Four researchers are employed at the Department of Microbiology and Immunology, University of Melbourne, at the Peter Doherty Institute for Infection and Immunity.

One researcher received grants from the two Australian entities—National Health and Medical Research Council (NHMRC) and the Medical Research Future Fund (MRFF)—as well as from the U.S. National Institutes of Health (NIH).

mRNA Safety Concerns

Another preprint study published in October last year also arrived at similar conclusions. It found a “substantial increase” in IgG4 antibodies in healthy people after they were given the third mRNA vaccine dose. The median IgG4 level was found to be 21 percent of all IgG antibodies.

A January 2023 study published in the National Library of Medicine made similar findings as well. Several months after the second dose of an mRNA COVID-19 vaccine, the antibodies were found to be “increasingly composed” of IgG4, which increased further after the third dose.

“IgG4 antibodies among all spike-specific IgG antibodies rose, on average, from 0.04 percent shortly after the second vaccination to 19.27 percent late after the third vaccination.”

Rising IgG levels have also been documented by studies investigating other negative effects of COVID-19 vaccinations.

A Jan. 2 study found links between COVID-19 booster shots and diabetes. Researchers discovered that spike protein levels and IgG antibodies “significantly increased” after subjects were vaccinated.

Another study from March 2023 noticed positive links between COVID-19-recovered individuals and certain antibodies in saliva. It found that those who recovered from a COVID-19 infection had higher salivary IgG.

IgG4-related diseases usually affect organs like salivary glands, thyroids, lungs, kidneys, pancreas, and bile ducts. The disease is typically found among middle-aged to elderly males. In some rare cases, children can also be affected.

Many people who have IgG4-related diseases may not show any symptoms or signs until a diagnosis is made months or years after the illness begins. As such, the affected organ may already be undergoing damage by the time medical attention is sought.

Some of the common symptoms of IgG4-related diseases are inflammatory tissue in the thyroid, enlarged kidneys, bulges below the chin or sides of the face, weight loss, and urine flow from kidneys getting blocked.