Background: During subcutaneous immunotherapy (SCIT), injections should be separated from vaccinations against infectious diseases by at least 1 week, because it is assumed that adverse reactions can result from the additional activation of the immune system.
Metarial and methods: Data of a total of 875 individuals receiving SCIT and/or vaccination in one ENT-practice were included and analyzed retrospectively. 444 individuals had received vaccination against infectious diseases, 336 allergic patients received only SCIT. Moreover, 79 allergic patients had received vaccination and SCIT injections simultaneously on one day in different locations, while 16 patients inadvertently received SCIT injections within up to 4 days after vaccination. Some of the patients were observed for consecutive years receiving several vaccinations parallel to SCIT. Systemic reactions (SRs) during SCIT were classified according to the WAO (World Allergy Organization) grading.
Results: Patients exclusively receiving vaccinations did not report any drug-related SR. One SR third grade and two SRs second grade occurred in 3 asthmatic patients exclusively receiving SCIT. The patients simultaneously receiving vaccination and SCIT did not have any SR. This was also the case for the subjects consecutively receiving parallel SCIT and vaccination for up to 5 years.
Conclusion: The international guidelines for allergen-specific immunotherapy (SIT) recommend an intermission of at least one week between SCIT and the administration of vaccines. However, these findings demonstrate the possibility to shorten or abolish this interval without increasing the risk of SRs.
Keywords: IgE-mediated allergy, simultaneous application; Vaccination against infectious diseases; allergen-specific subcutaneous immunotherapy.