Patients with COVID-19 vaccine reactions may be hesitant to get additional doses
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Key takeaways:
- Delayed large local skin reactions were most common.
- 40% had a negative change in their perception of the vaccine.
- 77% said they were unlikely to get additional vaccination.
Negative reactions to COVID-19 vaccines such as local skin reactions and hives may drive hesitancy to receive additional doses, according to a study published in Annals of Allergy, Asthma & Immunology.
Even individuals who showed no hesitancy before vaccination expressed hesitancy after these reactions, Kimberly G. Blumenthal, MD, MSc, quality and safety officer for allergy, Massachusetts General Hospital, and colleagues wrote.
“Amidst COVID-19 resurgence, it is essential to understand and address vaccine hesitancy as primary and booster vaccinations are our first line of defense in combatting the spread of COVID-19,” Blumenthal told Healio.
These factors prompted the researchers to use registry-based surveys to study reactions to the mRNA COVID-19 vaccines, collecting information on participants’ reactions and their overall feelings about vaccination.
“This research allowed us to understand factors that contribute to vaccine hesitancy,” Blumenthal said.
Study design, results
The researchers collected data from patients who enrolled in the Massachusetts General Hospital COVID-19 Vaccine Allergy Registry between April 12, 2021, and April 3, 2022. Forms included free-text questions about COVID-19 vaccine hesitancy, defined as reluctance or refusal to vaccinate despite the availability of vaccines.
The 993 respondents who self-reported reactions to COVID-19 vaccination and completed at least one free-text question had a median age of 46 years (interquartile range, 36-59 years). Also, 88% were female, and 82% were white.
Reactions occurred after the first (41%), second (24%), third (25%) and fourth (9%) doses, with less than 1% not reporting which dose prompted the reaction.
Also, 65% reported which type of vaccine they received, including Moderna’s mRNA-1273 (45%), Pfizer’s BNT162b2 (16%), Johnson & Johnson’s Ad26.COV2.S (3%) and Oxford-AstraZeneca’s ChAdOx1 (< 1%).
Reactions included delayed large local skin reactions (40%), hives/urticaria (32%), immediate large local skin reactions (3%), swelling (3%), anaphylaxis (2%) and other or unspecified (20%).
Fifty-six percent of respondents said that they did not have any concerns about reactions before they were vaccinated. But when the registry asked them if their concerns had changed, 40% said their views of the vaccine had changed from positive or neutral to negative.
Also, 27% said their views remained positive, 14% said their views remained negative, and 1% said their views had changed from negative to positive.
When the registry asked 102 of the respondents if they intended to receive future vaccinations, 79 (77%) said they were “unlikely” or “very unlikely” to do so, with 96% attributing this hesitancy to side effects.
Factors that impacted whether respondents chose vaccination included a desire for more information about reactions (71%), premedication (32%), protection of loved ones (31%) and more information about vaccine safety (20%).
Respondents aged younger than 30 years were more likely to have a negative change in their perception of vaccines compared with respondents who were aged 65 years and older (OR = 1.68; 95% CI, 1.02-2.77).
Also, respondents who had reactions following their second, third or fourth doses were more likely to have a negative change than respondents with a reaction after the first dose (OR = 1.44; 95% CI, 1.09-1.91).
Respondents who had hives were more likely to have a negative change as well (OR = 1.96; 95% CI, 1.42-2.71). However, the researchers said, there were no significant associations between negative changes and sex, race or ethnicity, or history of prior reactions.
Overall, Blumenthal noted that an individual’s experience of a skin or allergic reaction had a greater influence on vaccine hesitancy than the medical severity of their reaction.
“This is demonstrated by our finding that hives, a non-severe but potentially impactful and occasionally chronic reaction, were associated with increased negative perception of vaccination when compared to anaphylaxis, a potentially life-threatening short-term reaction,” she said.
This is significant because it demonstrates that fear of long-term or chronic side effects has a major influence on the development of vaccine hesitancy, Blumenthal continued.
“Additionally, it demonstrates a potential disconnect between physicians and patients regarding vaccine reactions, as while a physician may determine an acute reaction to not be severe, a patient may perceive their reaction to be more severe depending on its chronicity and impact on daily life,” she said.
Six major themes emerged during analysis of the responses indicating negative changes in perception: negative experiences with side effects (53%), lack of available information (8%), unknown future effects of the vaccine (7%), unknown etiology of reaction (3%), lack of research (3%) and distrust of information (1%). A quarter of these respondents (25%) did not provide any explanation.
Three themes emerged when respondents were asked what would most influence their decision to accept a future vaccination: lack of information, negative experiences with reactions and refusal or reluctance for future doses.
Respondents who expressed a desire for more resources wanted information available at the time of vaccination, access to medical advice for post-vaccination symptoms, research about vaccines, post-vaccination symptoms to be monitored in the following weeks and months, and longer monitoring at the vaccination site.
Informing future approaches
A better understanding of the motives behind vaccine hesitancy is important in promoting booster uptakes, the researchers said, especially among individuals who were not concerned about the vaccine before receiving it but who then experienced side effects, as the virus evolves and natural immunity wanes.
The promotion of booster shots needs to be fundamentally different from the promotion of the primary series of vaccines, the researchers continued, with an emphasis on providing information about side effects before shots are administered instead of after reactions are experienced.
“We recommend that doctors with hesitant patients are clear about the data — what is known and still unknown,” Blumenthal said. “One of the most influential factors we found on patients’ decisions for future vaccination was a lack of information.”
The study also suggests that a shared decision-making framework may be useful for all patients experiencing hesitancy due to allergic or skin reactions, she continued.
“By providing patients with resources prior to vaccination that discuss the safety of the COVID-19 vaccines, along with the type and severity of reactions that people experience, patients could approach vaccination with less uncertainty,” Blumenthal said.
By following up with patients after vaccination and sharing information on how to respond to reactions, she continued, they may feel more supported by their health care team, which would contribute to reduced vaccine hesitancy.
“It is also important to expand mRNA vaccine research to include the study of these reactions to gain a deeper biological explanation,” Blumenthal said.
For more information:
Kimberly G. Blumenthal, MD, MSc, can be reached at kblumenthal@mgh.harvard.edu.