Comparison of medium-term adverse reactions induced by the first and second dose of mRNA BNT162b2 (Comirnaty, Pfizer-BioNTech) vaccine: a post-marketing Italian study conducted between 1 January and 28 February 2021.

OBJECTIVES: On 21 December 2020 the European Commission granted conditional marketing authorisation in the European Union for the anti-COVID-19 mRNA vaccine Bnt162b2 (Comirnaty, Pfizer/BioNTech). The main endpoint of this epidemiological, observational, prospective and monocentric study was to identify the number, types, and severity of adverse events following immunisation that occurred in subjects who had been previously infected with COVID-19, and in those who had not, after vaccination with Comirnaty, and to compare the two groups of subjects looking at events that occurred within a month after the first and the second dose. METHODS: Data were gathered by a questionnaire. The results included the responses of all healthcare workers (2030) of the IRCCS Sacro Cuore Don Calabria Hospital (Italy) vaccinated between 1st January and 28th February 2021. Adverse effects of the vaccine were reported after the first and the second doses. RESULTS: There was a statistically significant increase (p<0.001, χ2=35.60) in participants who experienced some side-effects after receiving the first dose of the vaccine and who had previously been infected with the coronavirus, compared with participants who had not previously been infected. 46.76% (136) of the participants who had previously been infected experienced some side-effects after the first dose of vaccine, and 63.23% (184) experienced some side-effects after the second dose, compared with 29.15% (507) after the first dose and 70.79% (1231) after the second dose in those who had not been previously infected. The number of participants who experienced side-effects after the second dose and had previously been infected was significantly lower compared with participants who had not previously been infected (p=0.0094, χ2=6.743). CONCLUSIONS: Most of the side-effects identified in this trial were also reported by the manufacturer and the US Food and Drug Administration. Active surveillance should always continue to constantly check the vaccine's risk/benefit ratio over time.

Dabigatran-Induced Nephropathy and Gastrointestinal Bleeding and Its Successful Treatment with Idarucizumab: A Case Report.

Recently, the atrial fibrillation treatment guidelines have been updated to now recommend Non-vitamin K antagonist oral anticoagulants (NOACs) as the preferred alternative to warfarin for systemic embolism and stroke prevention in patients with non-valvular atrial fibrillation. NOACs have major pharmacologic advantages over warfarin, although the most common complications are gastrointestinal bleeding and NOAC-induced nephropathy within 6 weeks after starting therapy, as several recent case-reports stated. We are reporting for the first time a chronic delayed adverse reaction (regularly reported to Authorities) observed in an 82-year-old woman 27 months after starting dabigatran (110 mg twice a day), characterized by concomitant gastrointestinal bleeding and nephropathy. Idarucizumab administration immediately improved both bleeding and renal parameters. Moreover, we are going to highlight the importance of the compliance, the adherence to the therapeutic plan and the supervision of the Hospital Pharmacy on drug prescriptions. In fact in our case, dabigatran was firstly prescribed by the neurologist and delivered by the hospital pharmacy, but the patient continued the treatment for 27 months, prescribed by general practitioner without any laboratory control. This lack of supervision certainly contributed to the onset of the adverse reaction reported.