Little Rock hospital taking part in study on vaccine’s effects

Clinical trial to probe adverse responses

Although severe reactions to coronavirus vaccines are rare, researchers still know little about why some people have adverse responses to the shots while others do not.

A new clinical trial is attempting to find answers.

The trial, sponsored by the National Institute of Allergy and Infectious Diseases, part of the National Institutes of Health, is taking place at more than two dozen study sites across the United States.

Arkansas Children’s Hospital in Little Rock, which is working in partnership with researchers at the Translational Research Institute at the University of Arkansas for Medical Sciences, has been selected as one of the sites.

The trial, called Systemic Allergic Reactions to SARSCoV-2 Vaccination, is specifically studying reactions to the Moderna and PfizerBioNTech vaccinations. These vaccines, known as

mRNA, are made of genetic material from the coronavirus that helps human immune systems create antibodies against the virus.

While mRNA vaccines have been in development for about 30 years, the covid-19 pandemic is the first time the technology has been widely used to fight disease, Dr. Akilah Jefferson, one of the study’s researchers, said.

“This [mRNA] technology is a very good one and can be modified for different infectious diseases,” said Jefferson, a UAMS assistant professor and allergist at Arkansas Children’s Hospital. “We think it will be used going forward not only for coronaviruses but for other viruses.”

Jefferson added: “So for using this same technology for a long time, we need to be able to tell people what their risk is and to be able to tell health providers the best way to get their patients vaccinated safely.”

The trial is enrolling 3,400 adults ages 18 to 69 at up to 35 academic allergy research centers nationwide. Arkansas Children’s and UAMS began enrolling participants April 1 with the goal of enlisting 115 people, Jefferson said.

TWO GROUPS

Participants, who will be financially compensated, will be separated into two groups.

The first group will have about 60% of the participants, who must have a history of severe allergic reactions or a diagnoses of a mast cell disorder, “a disease caused by a type of white blood cell called a mast cell that is abnormal, overly active, or both, predisposing a person to life-threatening reactions that look like allergic reactions,” according to a news release from the National Institutes of Health.

The second group, 40% of participants, must have a history of no allergic reactions.

About two-thirds of those enrolled in each group will be female because “data out so far indicates women are more likely to have these reactions than men,” Jefferson said.

Participants will be given Moderna, Pfizer or a placebo. Those who receive the placebo will later be given doses of Moderna or Pfizer vaccine.

“The public understandably has been concerned about reports of rare, severe allergic reactions to the Moderna and Pfizer-BioNTech covid-19 vaccines,” Dr. Anthony Fauci, director of the National Institute of Allergy and Infectious Diseases said in a 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,” Fauci said. “However, for most people, the benefits of covid-19 vaccination far outweigh the risks.”

Severe allergic reactions, also called adverse events, are about five cases per 1 million Pfizer vaccines administered and about two per 1 million doses of Moderna given, Jefferson said.

An example of a severe reaction is anaphylaxis, symptoms of which include skin rash, nausea, difficulty breathing and shock. If not treated immediately, usually with a drug called epinephrine, it can result in unconsciousness or death.

“Allergic reactions to the vaccines are still exceedingly rare,” Jefferson said. “The risk is very low generally speaking.”

Emergency medications, oxygen and other equipment in addition to trained allergists will be on site to observe participants in the trial.

“Most of the rare, severe allergic reactions to these vaccines have occurred in people with a history of allergies,” the National Institutes of Health has said. “A substantial number of these people had previously experienced a life-threatening allergic reaction called anaphylaxis.”

Most people experience reactogenicity to covid-19 shots and other vaccinations. Examples of this would be soreness at the site of the injection, muscle aches, fatigue or fever that lasts for a few hours or a couple of days.

“That is not unusual for any type of vaccines, and it is not unusual for these vaccines,” Jefferson said.

Participants in the study will be asked to make three to four visits for monitoring and also for the collection of blood and urine samples, which will be sent to National Institutes of Health laboratories for analysis.

ALLERGIC REACTIONS

Researchers are monitoring systemic allergic reactions within at least 90 minutes of receiving an injection, the National Institutes of Health said. This type of reaction “occurs in one or more parts of the body beyond the injection site,” the agency said.

“If such an allergic reaction occurs in study participants, investigators will assess whether the reactions are more frequent in participants who are highly allergic or have a mast cell disorder than in participants with no allergic history,” the National Institutes of Health said in an announcement about the trial.

“In addition, investigators will examine the biological mechanism behind the reactions and whether a genetic pattern or other factors can predict who is most at risk,” the news release said.

The hope is that with understanding of why some people have severe reactions, the mRNA vaccines could be modified or health care providers can better identify and prevent the reactions ahead of a high-risk individual receiving a shot.

This could reduce vaccine hesitancy as well as further increase the safety of the vaccines as they are more widely used in the future, Jefferson said.

“It is a lofty goal, but I think it is an important one,” she said. “MRNA technologies are not going away, and they are very good technologies, so we have to do our best to figure out if there is something in that particular technology that is the problem so we can better help people the next time we need to vaccinate, whether with booster shots or for other emerging diseases.”

Results are expected late this summer.