Efficacy and safety of an e-consult program for COVID-19 vaccine allergy concerns

Abstract

Background:

Although severe allergic reactions to coronavirus disease 2019 (COVID-19) vaccines are rare, fear of allergic reactions remains a major source of vaccine hesitancy. For concerned patients and providers alike, allergist consultation is recommended for further guidance on the risk of vaccination. The electronic consultation (e-consult) medium has the potential to make this guidance more widely accessible, thereby supporting vaccination efforts.

Objective:

To determine the safety and efficacy of an e-consult program for COVID-19 vaccine allergy concerns.

Methods:

We performed a retrospective analysis of a single-center COVID-19 vaccine allergy e-consult program. Data on demographics, allergy history, and outcomes after recommendations were gathered via review of the electronic medical record (EMR). Patients without EMR data available following the e-consult were called to inquire about vaccination status.

Results:

Our study included 64 patients, most of whom (51.6% [33/64]) had e-consults placed for second-dose concerns. E-consults were completed within 2 days for all patients. The most common recommendation was that patients receive any COVID-19 vaccination available (62.5%, [40/64]). Forty-one patients (64.1%) were vaccinated after receiving recommendations from an allergist, 11 of whom (26.8%) reported a vaccine reaction. Most of these reactions were nonallergic (9/11 [81.2%]). No anaphylactic events were reported.

Conclusion:

Results of our study suggest that e-consults were a safe and effective method of providing guidance with regard to COVID-19 vaccine risk in patients with concerns about allergic reactions. The efficiency of this medium, highlighted by the 2-day turnaround time in our study, has the potential to expand access to vaccine risk evaluations by board-certified allergist/immunologists.

Since the introduction of coronavirus disease 2019 (COVID-19) vaccines, fear of adverse reactions has represented a major source of vaccine hesitancy.¹ For patients with allergy histories, including drug or vaccine hypersensitivity or a previous reaction to a COVID-19 vaccine, fear of allergic reactions is of particular concern. Yet, severe allergic reactions to COVID-19 vaccines remain rare.² For concerned patients and providers alike, allergist consultation is recommended for further guidance on the risk of vaccination.³ These consultations are particularly amenable to the electronic consultation (e-consult) format, as they are time sensitive and hinge on data that can be readily extracted from the electronic medical record (EMR).

A previous study that examined the use of e-consults in an allergy/immunology practice highlighted their prevalence in evaluation of adverse drug and vaccine reactions as opposed to other common allergist referral concerns, such as rhinitis, sinusitis, or angioedema.⁴ Although e-consult programs have also been implemented specifically for COVID-19 vaccine concerns in the past,⁵ to our knowledge, there are no published studies regarding the safety and efficacy of these programs. Our study aimed to evaluate the outcomes of a single-center COVID-19 vaccine allergy e-consult program to determine if this model is fit for replication at other centers.

METHODS

We performed a retrospective analysis of a single-center COVID-19 vaccine allergy e-consult program. Allergist e-consults were placed by primary care physicians at our tertiary-care medical center for two indications: (1) regarding risks of initial COVID-19 vaccination in patients with concerning allergy histories, or (2) regarding risks of continuing the vaccination series after a previous adverse reaction. All patients with e-consults completed between March 1, 2021, and March 1, 2022, were included. Using the EMR, data on demographics, allergy history, and outcomes after recommendations were gathered. If no data were available in the EMR after the e-consult, the patients were called to inquire about vaccination status. This study was granted institutional review board exemption.

We classified allergist recommendations into four categories, from least restrictive (no contraindication to any COVID-19 vaccine) to most restrictive (avoid all COVID-19 vaccines), although recommendations often included nuances based on specific patient cases. Nonallergic adverse reactions after vaccination were classified in severity from grades 1 to 4 according to the U.S. Food and Drug Administration toxicity grading scale for healthy adult and adolescent volunteers enrolled in preventive vaccine clinical trials.⁶ Allergic reactions were classified in severity from grades 1 to 5 according to recent expert consensus guidelines.⁷

RESULTS

Our study included 64 patients, 79.7% of whom were women and 73.4% of whom were white (Table 1). Most patients had at least one allergy listed in their chart, with the majority of these being medication allergies. Notably, 25% of the patients (16/64) had previous vaccine reactions to non–COVID-19 vaccinations. Approximately half of all e-consults (51.6% [33/64]) were placed for second-dose concerns, 5 (15.2%) of which involved a previous COVID-19 vaccine reaction classified as allergic. Approximately one-fourth (23.4% [15/64]) of all the e-consults were placed for third-dose concerns, 3 (20%) of which involved a previous COVID-19 vaccine reaction classified as allergic.

Table 1.

Characteristics of patients included in the study (N = 64)

COVID-19 = Coronavirus disease 2019.

*Included non–COVID-19 vaccine reactions in five patients, specific component allergies in two patients, chronic conditions in two patients, food or medication allergies in two patients.

#Included facial swelling, urticaria.

§Included chest tightness, dysphagia.

¶Included concern for polysorbate allergy.

‖Included tongue swelling.

**Included urticaria.

##Included concern with regard to previous non–COVID-19 vaccine reaction.

E-consults were completed by either of two board-certified allergist/immunologists (S.J. and K.A.) within the same day for 73.4% of the patients (47/64) and within 2 days for all patients. Of the four categories of allergist recommendations, the most common was that patients receive any COVID-19 vaccination available (62.5% [40/64]) (Table 2). Notably, in-person allergy referral for vaccination and prolonged observation in the clinic was recommended for two patients, both of whom were deemed high risk for allergic reactions due to development of urticaria after their second vaccination. Further evaluation by other subspecialties was recommended for four patients with concerning postvaccination symptoms that were deemed nonallergic in nature.

Table 2.

E-Consult outcomes

E-consult = Electronic consultation; COVID-19 = coronavirus disease 2019.

*Included another subspecialty referral in four patients, in-person allergy evaluation in two patients.

#Included two patients referred for evaluation of reactions to a third COVID-19 vaccination.

§Included rash and nausea.

¶Included fever and fatigue.

‖Included dizziness.

**Included pneumonia.

##Included self-resolved facial swelling in one patient, nausea and/or flushing in one patient who required ondansetron and cetirizine.

Of the 41 patients (64.1%) who were vaccinated after receiving recommendations from an allergist, a total of 11 patients (26.8%) reported a vaccine reaction, most of which were nonallergic (9/11 [81.2%]). One patient developed a grade 4 adverse event in the form of a community-acquired pneumonia 2 days after vaccination, which was thought to be unlikely due to the vaccine. Two reactions were classified allergic by an allergist/immunologist, (K.A.) both of which were grade 2. One of these patients, who was undergoing vaccination in allergy/immunology clinic due to risk level, required medication (cetirizine and ondansetron). No anaphylactic events were reported, and epinephrine was never required for treatment.

DISCUSSION

The main objective of this study was to establish the safety and efficacy of an allergist e-consult program for addressing COVID-19 vaccine allergy concerns. Three-fourths of the patients for whom e-consults were submitted (48/64 [75%]) received a specific vaccine recommendation without the need for additional information or evaluation. Over half of the patients who were evaluated (64.1% [41/64]) received COVID-19 vaccines after the E-consult response, with no severe hypersensitivity reactions reported. Although one patient developed a grade 4 adverse event, this was thought to be more likely due to a bacterial infection rather than vaccination, highlighting the need for a multidisciplinary approach when evaluating and treating postvaccination symptoms. Although allergists are uniquely equipped to comment on hypersensitivity to vaccine components and identify immunoglobulin E–mediated reactions (IgE), input from other providers is often indicated for symptoms that are beyond the scope of allergy practice.

In addition, our study highlights the efficiency of the E-consult medium. While wait times for in-person allergist evaluation vary significantly based on geography, patients often wait weeks to months for an initial visit. This is of particular concern with regard to COVID-19 vaccination, as prolonged wait times could potentially cause delays in vaccination and leave patients less protected from severe disease in the interim. In our study, allergists were able to deliver recommendations within 2 days for all patients, drastically reducing wait times and expediting vaccination efforts.

There were two main limitations to our study. First, there was no control group of patients with vaccination concerns for whom expert e-consultation was not requested. Thus, we were unable to quantify the increase in adherence to vaccination that occurred as a result of our program. Second, this e-consult program was implemented within a large academic health system in which allergists had access to most clinical records available for the patients of interest, which potentially limits generalizability. In a setting such as a community practice, where allergists may not have these records readily available, it may be more difficult to generate recommendations without seeing patients in clinic or requesting additional history from referring providers. Consequently, turnaround times for e-consults may vary significantly.

CONCLUSION

Vaccine hesitancy remains a key barrier to decreasing COVID-19 transmission and protecting patients from severe disease. The results of our study suggest that electronic consultation is an effective method of providing guidance regarding COVID-19 vaccine allergies and adverse reactions, which can enable allergists to efficiently address patient and provider concerns. Future studies are needed to provide additional data about generalizability. Additional areas of interest include racial disparities in e-consult access as well as applications of similar e-consults to other vaccine allergy concerns.