Could Repeated COVID mRNA Vaccines Backfire? The IgG4 Antibody Connection

A recently published 2023 study suggests repeated mRNA COVID vaccines could trigger an unusual immune response that weakens future virus defenses.

This controversial topic continues to evolve as new evidence emerges. The study was published in May 2023 in the journal Vaccines. It builds on other recent research indicating mRNA vaccines might increase an unconventional antibody called IgG4 when doses are repeated. This doesn’t seem to happen with viral vector vaccines like AstraZeneca.

The authors note that while mRNA vaccines are considered safe for most people, ongoing monitoring of rare side effects is important, especially with new vaccine technologies. Individuals should weigh emerging benefits and risks in discussion with their doctors.

Key Terminology

• mRNA vaccines: A new type of vaccine that uses messenger RNA to provide instructions to our cells to build protection against a virus. It’s like getting a software update for our cells!
• Spike protein: The spike-shaped proteins on the surface of the SARS-CoV-2 virus that mRNA vaccines train your body to recognize. Picture the spiky crown on the Statue of Liberty – that shape inspired the name!
• IgG4 antibodies: A type of antibody made by the immune system. Antibodies act like little soldiers who bind onto viruses to stop infections. IgG4s are the unconventional, flexible soldiers in the army.
• Immune tolerance: When the immune system gets so used to seeing something over and over that it stops responding effectively. It’s like how your brain tunes out the construction noise you hear every day.
• Viral vector vaccines: Vaccines that use a modified virus as a delivery system to teach cells to make viral proteins and trigger an immune response. For example, the AstraZeneca and Johnson & Johnson COVID-19 vaccines use this approach.
• Antigen: The specific molecule or substance an antibody binds to, like a lock and key. A burglar’s tools are antigens that police antibodies work to target.
• Complement system: Proteins that help antibodies kill viruses and mark them for destruction. The demolition team that comes in after the antibody police do their job!

Introduction to mRNA Vaccines and Waning Immunity Concerns

mRNA vaccines like Pfizer and Moderna use novel technology to induce an immune response against the SARS-CoV-2 spike protein. Over 13 billion doses have been administered globally so far.

However, experts have raised concerns about waning immunity. mRNA vaccines do not provide sterilizing immunity and fully vaccinated individuals can still get infected and transmit COVID-19.

Recent studies also reveal mRNA vaccines can trigger increased levels of unconventional IgG4 antibodies with repeated injections. This phenomenon is not seen with viral vector vaccines like AstraZeneca.

IgG4 Antibodies – Hero or Villain?

IgG4 is a unique subtype of IgG antibodies, which are Y-shaped proteins made by plasma cells that bind to pathogens. Compared to other IgG subtypes, IgG4:

• Is found in very low levels normally
• Can undergo “half-antibody exchange” causing bi-specific, monovalent binding. This means the two arms of the Y detach and recombine randomly.
• Does not activate immune cells or proteins effectively

In some cases, IgG4 acts like an anti-inflammatory antibody. This may help resolve chronic inflammation from long-term allergy treatments.

However, IgG4 may also contribute to tumor immune evasion and some autoimmune conditions. The high IgG4 levels seen in repeated mRNA vaccination may have an inhibitory effect on immune defenses.

Factors Influencing IgG4 Antibody Production

Research identifies three key factors triggering increased IgG4 levels:

• High antigen dose – mRNA vaccines contain very high spike protein doses
• Getting multiple doses – mRNA vaccine boosters
• Vaccine type – this effect is seen with mRNA vaccines but not viral vector vaccines like AstraZeneca

Studies on experimental vaccines for conditions like HIV, malaria, and acellular pertussis have also caused elevated IgG4 when given at high doses repeatedly.

Potential Implications of mRNA-Induced IgG4 Increase

Experts warn the spike-specific IgG4 triggered by mRNA vaccines:

• Is non-neutralizing and fails to activate immune cell responses
• May promote immune tolerance to the spike protein upon re-exposure
• Could enable unchecked viral replication and chronic infection
• Along with effects of COVID-19 itself, may re-activate dormant viruses or potentially enable cancer growth
• With repeated over-stimulation, risks provoking autoimmune reactions

Scientists caution against getting more doses than recommended, especially in people with weakened immunity who may also be most vulnerable to severe COVID-19. Those with weakened immunity may face the highest risks from repeat mRNA vaccination.

While more research is still needed, individuals are advised to carefully consider emerging benefits and risks. Work closely with your healthcare provider and share key resources like this PubMed (nih.gov) review to help them make informed, personalized medical decisions.

FAQs on mRNA Vaccine Safety and IgG4 Antibodies

Q: Are mRNA vaccines safe?

A: mRNA vaccines are considered safe for most people, but ongoing monitoring of rare side effects is important, especially with new vaccine technologies.

Q: Should I get an mRNA vaccine booster?

A: This depends on individual factors. Some experts only recommend boosters for those at highest risk. Discuss with your doctor.

Q: What about other vaccine types?

A: Viral vector vaccines don’t appear to increase IgG4 like mRNAs. But each platform has unique potential adverse effects.

Q: How concerned should I be about IgG4 antibodies?

A: The implications are still being investigated. Those with weakened immunity may face higher risks. More research is underway.

Q: What is waning immunity?

A: Waning immunity means that the protection from a vaccine decreases over time.

Q: What does ‘over-vaccination’ mean?

A: Over-vaccination refers to receiving more doses of a vaccine than recommended, which could potentially lead to adverse effects.

The key is making informed decisions based on the latest evidence. Stay up to date and work closely with your healthcare providers to navigate emerging science on both vaccine risks and benefits.

Source:

• IgG4 Antibodies Induced by Repeated Vaccination May Generate Immune Tolerance to the SARS-CoV-2 Spike Protein – PubMed (nih.gov)
• Vaccines | Free Full-Text | IgG4 Antibodies Induced by Repeated Vaccination May Generate Immune Tolerance to the SARS-CoV-2 Spike Protein (mdpi.com)