Allergic Responses to Moderna’s Vaccine Extremely Rare

You’re as likely to get struck by lightning.

Tara Fernandez
Jan 24 · 4 min read

A poll of different segments of the U.S. population revealed that some people may be more afraid of the COVID vaccine than the virus itself. 35 percent of Black adults said they definitely or probably would not get the vaccine. Also in this group were 33 percent of essential workers and 36 percent of adults between the ages of 30 and 49. For those that voted no, the source of the anxiety likely stems from the possibility of developing an adverse reaction to the vaccine.

Allergy experts believe such fears to be completely unfounded. NYU Langone Health’s Purvi Parikh, M.D., who specializes in infectious disease allergy and immunology, says true allergic reactions to vaccines are exceedingly rare.

“Statistically, you’re more likely to be hit by lightning than have a true anaphylactic reaction to a vaccine,” said Parikh. The odds of being struck by lightning in a given year is 1 in 500,000. But what are the odds of reacting poorly to the COVID mRNA vaccine specifically?

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2.5 in a million

About the same says a recent report released by the Centers for Disease Control and Prevention (CDC). From the end of December to early January, over four million people received a shot of Moderna’s COVID-19 vaccine. Of these, only 10 developed a serious, potentially life-threatening allergic reaction known as anaphylaxis.

At 2.5 adverse events for every 1 million individuals vaccinated, these low odds should be reassuring. “Based on this early monitoring, anaphylaxis after receipt of Moderna COVID-19 vaccine appears to be a rare event,” say authors of the CDC report.

It may be rare, but it’s understandable why people are afraid of anaphylaxis. In these cases, the situation escalates quickly. The immune system comes out in full force, guns blazing, flooding the body with inflammatory chemicals. Within minutes, the blood pressure plunges and airways tighten, restricting breathing. Without immediate intervention, the symptoms can be fatal.

None of the 10 individuals who reacted to Moderna’s vaccine died, however, and all made a full recovery after receiving epinephrine shots or, in the worst cases, emergency hospitalization.

Why did these 10 people develop these side effects in the first place? For now, we don’t fully know. The common thread between them appears to be having known drug sensitivities to medications such as penicillin. One individual had allergies to certain foods and environmental factors.

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Something in the water?

According to research, vaccine skeptics are programmed differently than the rest of us, chronically overestimating the likelihood of negative events, especially the rare ones. Many believe the vaccine contains “toxic” elements that trigger these adverse reactions.

Most of the half a milliliter vaccine dose is water. And the main ingredient is mRNA, genetic material present in human cells. The vaccine’s mRNA encodes the recipe for SARS-CoV-2’s spike protein, projections that stick out of the surface of the virus giving it its signature crown-like appearance. The virus also uses the spike protein as a key, allowing it to infiltrate human cells.

The vaccine provides the recipe and the body’s cells do the cooking, synthesizing just the spike protein elements of the virus and presenting them on the surface of their membranes. This then gets picked up by immune cells that begin to churn out protective antibodies against the spike protein. If they ever encounter the real virus, they’ll be ready to launch a full-blown attack and resist infection.

The coronavirus isn’t the first target of vaccines in an mRNA format. Other vaccines to keep other viruses at bay (influenza, Zika, rabies, and cytomegalovirus, for instance) have been in the works for years.

Trust falling into 2021

Two shots, a month apart, are enough to give vaccinated individuals 94.1 percent, say data from clinical trials of Moderna’s vaccine. Surely that’s enough to set worried minds at ease?

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It’s not that simple, say,public health experts, who often speak about how community health initiatives move at the speed of trust. Instead of dismissing vaccine misconceptions, approaching these mistaken ideas with empathy will likely produce better results. Understanding that distrust may stem from long-standing historical reasons, barriers to accessible scientific information, or even a preoccupation with the risks over the potential for vaccines to save lives and the economy.

An estimated 500 million doses of the COVID vaccine are projected to roll out of Moderna’s doors this year, joining the growing list of approved therapies to treat and prevent COVID. Whether or not the safety data is enough to convince everyone to get vaccinated, they can trust that help is indeed on the way.

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Tara Fernandez

Written by

Cat person, PhD-qualified Cell Biologist & Science Writer. Interested in trends and emerging technologies in the biopharma industry.

BeingWell

BeingWell

A Medika Life Publication for the Medical Community

Tara Fernandez

Written by

Cat person, PhD-qualified Cell Biologist & Science Writer. Interested in trends and emerging technologies in the biopharma industry.

BeingWell

BeingWell

A Medika Life Publication for the Medical Community

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