Allergies to the mRNA-based COVID-19 vaccine are rare, generally mild, and found in a Stanford-led study.News center

For a more complete understanding of allergic reactions to new vaccines-how common and how serious they are-the research team found medical records of 38,895 mRNA-based COVID-19 vaccines in Stanford medicine. From December 18, 2020 to January 26, 2021. The vaccination included 31,635 Pfizer vaccines and 7,260 Modana vaccines.

Researchers searched medical records of vaccinated people for the treatment of allergic reactions and identified which reactions were associated with the vaccine. Twenty-two recipients, 20 of whom were women, were at risk of allergic reactions. This means that certain symptoms will begin within 3 hours of receiving the shot. Researchers looked for the following symptoms in the recipient’s medical records: Swelling of the mouth, lips, tongue or throat; shortness of breath, wheezing or chest tightness; or changes in blood pressure or loss of consciousness. Only 17 of the 22 recipients responded to meet the diagnostic criteria for allergic reactions. Three recipients received epinephrine, which is usually given for stronger anaphylaxis. All 22 have been fully recovered.

Of the 22 recipients, 15 had a medical history recorded by a previous allergic reaction physician, including 10 for antibiotics, 9 for foods, and 8 for non-antibiotic drugs. (Some recipients had multiple types of allergies.)

As important as what we found, we didn’t find it.

Researchers conducted follow-up tests on 11 individuals to identify the type of allergic reaction and what triggered the allergy. Was it one of the inert sugar or lipid components in the foam, or was it something else in the vaccine?

Research participants underwent a prick test in which a clinician injects a small amount of a potential allergen (lipid, sugar (polyethylene glycol or polysorbate), or the entire vaccine) into the skin. The prick test detects allergic reactions mediated by the form of antibodies known as immunoglobulin E or IgE. These reactions are generally associated with the most severe allergies.

None of the recipients responded to the prick test for the inert component of the vaccine, and only the skin of one recipient responded to the entire COVID-19 vaccine. Follow-up blood tests showed that the vaccine recipient did not have significant levels of IgE antibody against the vaccine component.

Skin tests did not explain the mechanism of the recipient’s allergic reaction, so researchers proceeded to another type of diagnostic test. Vaccinated people provided blood samples for testing allergic activation of immune cells known as basophils. Blood samples from 10 of the 11 participants responded to the inert component polyethylene glycol (PEG) used in both the Pfizer and Modana vaccines. In addition, all 11 recipients activated basophils in response to the entire mRNA vaccine when mixed with their own basophils.

All 11 subjects had high levels of IgG antibodies to PEG in their blood. IgG antibodies help activate basophils under several conditions. This finding suggests that individuals are likely to have been sensitive to PEG before receiving the vaccine.

“It’s as important that we didn’t find it as much as we did,” Nado said. “MRNA itself does not appear to cause an allergic reaction.”

In addition, the data suggest that the response to the COVID-19 vaccine was not generally the most serious form of allergic reaction, which is good news from a vaccine safety standpoint, she said. rice field. Allergic reactions mediated by IgG and basophils can be controlled by antihistamines, body fluids, corticosteroids, and close observation. This means that many people who respond to the first dose of vaccine can safely receive a second dose under medical supervision.

PEG is widely used as a stabilizer in household products, cosmetics and medicines, and women are more likely to be exposed to large amounts of substances, which may explain why women are more likely to have vaccine allergies. (Repeated exposure to the substance can sensitize the immune system and cause allergies.) Vaccine makers are less likely to cause allergies because most reactions were to PEG rather than the active ingredient of the vaccine. It may be possible to re-prescribe the vaccine with a variety of stabilizers, Nadow said.

Other Stanford University authors for this study are research assistants Theo Snow, Alexandra Lee, Mihil Shah, Eric Smith, Evan de, and Iris Chang. Andra Blomkalns, MD, Professor of Emergency Medicine. Brooke Betts, PharmD, clinical pharmacist; medical student Anthony Butzanko. Graduate student Joseph Gonzalez; Associate Professor of Sharon Chinthrajah, MD, Medicine and Pediatrics. Lab manager Diane Dunham. Grace Lee, MD, Professor of Pediatrics. Ruth O’Hara, MD, PhD, Dean of Research, Professor of Psychiatry and Behavioral Sciences. Helen Park, PharmD, Veteran Palo Alto Healthcare System clinical pharmacist. Vice President of Resurrection, RN, MPH, Quality, Safety and Clinical Effects, Chief Quality Officer of Stanford Healthcare. Sayantani Sindher, MD, Clinical Associate Professor of Medicine and Pediatrics. Director of Pharmacy Services at Deepak Sisodiya, PharmD and Stanford Health Care. Mindy Tsai, DMSc, Senior Research Scientist in Pathology. Stephen Gary, MD, Professor of Pathology and Microbiology and Immunology.

Nado is a member of Stanford Institute for Immunology, Transplantation and InfectionSenior Fellow, Stanford Woods Institute for Environmental Studies. Fellow of Stanford Innovation and Global Health Center. A member of Stanford’s Bill Lane Center in the Western United States.Nado and Gari are members Stanford Bio-X.. Nadeau, O’Hara, Galli Stanford Cardiovascular Institute..Nado and O’Hara Utsai Institute of Neuroscience At Stanford. O’Hara, Nadeau, Chinthrajah, Grace Lee, Sindher, Galli Stanford Institute for Maternal and Child Health.. Galli is a member of Stanford Cancer Institute..

Researcher at the Swiss Institute for Allergic Asthma at the University of Zurich. Imperial College London National Cardiopulmonary Research Institute. The Center for Asthma Allergy Mechanisms in London also contributed to this study.

This study is supported by the Asthma and Allergic Diseases Collaborative Research Center (Grant U19AI104209), National Institutes of Health (Grant R01AI140134), National Institute of Allergic Infectious Diseases SARS Vaccine Research (Grant UM1AI10956508), Parker Foundation, Crown. Was there. Foundation and Sunshine Foundation.