Background: Since first emerged in December 2019, the COVID-19 pandemic has resulted in a death toll surpassing 5.5 million worldwide and had severe consequences on the global economy, environment, public health and social life [1, 2]. Multiple potential vaccines against COVID-19 have been developed swiftly and as shown in several phase 3 clinical trials, they demonstrated considerable efficacy without an unusual safety signal in healthy individuals.

Objectives: In this study, we aimed to evaluate vaccine reactivity and disease flare following vaccination with either Sinovac/CoronaVac or Pfizer/BioNTech among BS and FMF patients compared with patients with various diagnosis of RD and healthy controls.

Methods: Only those patients and healthy controls who rece,ved at least one single shot of either CoronoVac or BioNTech against COVID-19 were included in the study. We tried to contact all of these patients and controls consecutively by telephone and attempted to make interviews with the eligible ones.

Results: We studied the efficacy, side effects and disease flares after COVID-19 vaccination in 256 patients with Behcet’s syndrome (BS), 247 with familial Mediterranean fever (FMF), 601 with rheumatic diseases (RD) and 612 healthy controls (HC). Study participants were vaccinated either with CoronaVac (BS:109, FMF: 90, RD: 343, and HC: 334) or BioNTech (BS: 147, FMF:157, RD: 258 and HC: 278). BioNTech ensured a significantly better efficacy than CoronaVac against COVID-19 in all patient groups (BS: 1.4% vs 10.1%; FMF: 3.2% vs 12.2%, RD:2.7% vs 6.4%). Those with at least one adverse event (AE) were significantly more frequent among those vaccinated with BioNTech than those with CoronaVac (BS: 86.4% vs 45%; FMF: 83.4% vs 53.3%; RD: 83.3% vs 45.5% and HC: 86.3% vs 52.1%). The majority of AEs were mild to moderate and transient and this was true for either vaccine. There were also AEs that required medical attention in all study groups following CoronaVac (BS:5.5%, FMF:3.3%, RD:2.9% and HC:3.3%) or BioNTech (BS:5.4%, FMF:1.9%, RD:4.7% and HC:4.7%). The main causes for medical assistance were disease flare, and cardiovascular events. Disease flares after vaccination were significantly more frequent among BS (41/256; 16.0%) and FMF (43/247; 17.4%) patients compared to patients with RD (36/601; 6.0%). This was true for both CoronaVac (BS: 11.0%, FMF: 24.4% and RD: 5.2%, p<0.001) and BioNTech (BS: 19.7%, FMF: 13.4% and RD: 7.0%, p=0.001)( Table 1 ).

Conclusion: Our study demonstrates that BS and FMF patients vaccinated with either CoronaVac or BioNTech demonstrated almost similar AE profile and frequency compared to RD patients and HC. AEs that required physician consultation or hospitalization occurred in all study groups after either CoronaVac or BioNTech. Caution should be required when monitoring these patients after vaccination. Increased frequency of flares in BS and FMF compared to that seen in RD might reflect defects in innate immunity and deserves further investigation.

REFERENCES:

[1] https://covid19.who.int Accessed date 22.01.2022

[2]Nicola M, Alsafi Z, Sohrabi C, Kerwan A, Al-Jabir A, Iosifidis C, Agha M, Agha R. The so-cio- economic implications of the coronavirus pandemic (COVID-19): A review. Int J Surg. 2020 Jun; 78:185-193. doi: 10.1016/j.ijsu.2020.04.018. PMID: 32305533; PMCID: PMC7162753.

Disclosure of Interests: Ayse Ozdede: None declared, Sabriye Güner: None declared, Guzin Ozcifci: None declared, Berna Yurttas: None declared, Zeynep Toker Dincer: None declared, Zeynep Atli: None declared, Ugur Uygunoglu: None declared, Eser Durmaz: None declared, Didar Ucar: None declared, Serdal Ugurlu Speakers bureau: Novartis,Pfizer,Celltrion and Lilly, Sebahattin Saip: None declared, Ömer Fehmi Tabak Speakers bureau: Abbvie, Gilead, MSD and GSK, Consultant of: Abbvie, Gilead, MSD and GSK, Vedat Hamuryudan: None declared, Emire Seyahi Speakers bureau: Pfizer, Abbvie, Novartis and Gilead,