NIH Trial Testing mRNA Vaccine Allergic Effects

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8 Apr. 2021. A clinical trial is underway testing for allergic reactions to Covid-19 vaccines using messenger RNA for invoking an immune response. The trial is conducted by National Institute of Allergy and Infectious Diseases or NIAID, part of National Institutes of Health, to study adverse allergic effects from vaccines made by BioNTech/Pfizer and Moderna.

Among the first vaccines authorized to combat the Covid-19 pandemic are those developed by biotechnology companies BioNTech in Mainz, Germany and licensed to global drug maker Pfizer, and Moderna in Cambridge, Massachusetts. Both the BioNTech and Moderna technologies are based on messenger RNA, a nucleic acid derived from the genetic code in DNA, and used by cells to produce amino acids in proteins for cellular functions. Both companies deliver messenger RNA or mRNA in lipid, or natural oil, nanoscale particles, where they instruct cells to produce antigens to invoke an immune response against the SARS-CoV-2 virus responsible for Covid-19 infections.

The clinical trial aims to better understand allergic reactions to mRNA vaccines among people predisposed to allergies, and non-allergic individuals. Early reports from Covid-19 vaccination sites show a few immediate allergic reactions to these vaccines, particularly among people with a history of allergies. The study is specifically recruiting participants known to be highly allergic or with a mast cell disorder, a condition where mast cells, a type of white blood cell in the immune system, overreact to drugs, some foods, or insect bites.

Two-thirds of participants are women

The mid-stage trial is enrolling 3,400 participants not yet vaccinated against Covid-19, age 18 to 69, of which two-thirds are women, since the vast majority of severe allergic reactions known as anaphylaxis to Covid-19 vaccines occur in women. Sixty percent of participants will have a history of severe allergies or a mast cell disorder, while 40 percent will have no history of allergies.

Participants are randomly assigned to receive a two-dose regimen of the BioNTech/Pfizer or Moderna vaccines, or a placebo. In the placebo group, however, placebos are given only as the first shot. About a month after the placebo injection, participants in this group will receive either the two-dose regiment of BioNTech/Pfizer or Moderna vaccines.

The study team is looking primarily for immediate allergic reactions to the mRNA vaccines. Trained clinicians will monitor vaccine recipients for allergic reactions in the 90 minutes following injections, and rate reactions from mild to severe on a standard five-point scale. Treatment for more severe reactions, says NIAID, will be available from clinician-monitors at the trial sites. Researchers are also collecting blood and urine samples before and after injections, and nasal swabs before injections, to find any associations between genetic characteristics and allergic reactions, as well as reveal biological mechanisms for these reactions.

“The public understandably has been concerned about reports of rare, severe allergic reactions to the Moderna and Pfizer-BioNTech Covid-19 vaccines,” says NIAID director Anthony Fauci in an NIH statement. “The information gathered during this trial will help doctors advise people who are highly allergic or have a mast cell disorder about the risks and benefits of receiving these two vaccines.”

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• Joint Venture Developing Oral Covid-19 Vaccine
• FDA Clears Covid-19 Nasal Spray/Drops Vaccine Trial
• Infographic – Steady Growth for mRNA Trials
• New Covid-19 mRNA Vaccine Trial Begins

Disclaimer: The author owns shares in Pfizer.

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