Enhanced passive safety surveillance of the quadrivalent inactivated split-virion influenza vaccine (IIV4) in Finland during the 2019/20 influenza season

Table 2 Comparison of reporting rates for all suspected adverse drug reactions between northern hemisphere influenza season 2018/19 and northern hemisphere influenza season 2019/20

	NH influenza season 2018/19 (time to ADR onset)		NH influenza season 2019/20 (time to ADR onset)^b
Analysis terms (or system organ class) preferred	≤7 days	Total	≤7 days	Total
Total number of VCs distributed		996		939
Total number of vaccinees who reported at least one suspected ADR	28	53	38	56
Vaccinee reporting rate, % (95% CI)	2.8 (1.78, 3.84)	5.3 (3.93, 6.71)	4.05 (2.79, 5.31)	5.96 (4.45, 7.48)
Total number of suspected ADRs	76	162	117	163
ADR reporting rate, % (95% CI)	7.6 (6.06, 9.46)	16.3 (14.03, 18.71)	12.46 (10.41, 14.74)	17.36 (14.99, 19.94)
Total number of vaccinees who reported at least one PRAC ADR of interest^a	27	48	36	56
Vaccinee reporting rate, % (95% CI)	2.7 (1.70, 3.72)	4.8 (3.49, 6.15)	3.83 (2.61, 5.06)	5.96 (4.45, 7.48)
Total number of PRAC ADRs of interest	47	96	77	112
PRAC ADRs of interest reporting rate, % (95% CI)	4.7 (3.49, 6.23)	9.6 (7.88, 11.64)	8.20 (6.53, 10.14)	11.93 (9.92, 14.17)

^aPRAC ADRs of interest for this EPSS are defined according to the ‘Interim guidance on enhanced safety surveillance for seasonal influenza vaccine in the EU’ adopted by PRAC on April 10, 2014 (EMA/PRAC/222346/2014)
^bValues in bold are those with a higher percentage in the current season compared with the upper limit of the 95% CI of 2018/19
Abbreviations: ADR adverse drug reaction; CI confidence interval; EMA European Medicines Agency; EPSS Enhanced Passive Safety Surveillance; NH northern hemisphere; PRAC Pharmacovigilance Risk Assessment Committee; VC vaccination card

ISSN: 1471-2458