Vasovagal reactions reported in COVID-19 convalescent plasma donors-NHSBT experience

ABSTRACT

Safety and efficacy of COVID-19 Convalescent Plasma (CCP) was tested as part of two large randomised controlled trials in UK (REMAP-CAP and RECOVERY). CCP collections by apheresis were started across NHSBT from early in the pandemic to support the trials. Data from CCP donors who had donated at least once in the period between April 2020 and March 2021 (inclusive) was reviewed. Of the 57 213 attendances during this period, 6908 (12.1%) resulted in at least one adverse event, reported within seven days of attendance. Donors experiencing an adverse event were more likely to be first-time donors than donors with no adverse event were. The risk of having any adverse event reduced from 14% for first-time donors to 7% for repeat donors. Bruising was seen in58%and vasovagal events were the second most commondonor adverse events accounting for 37% (2570/6908). Most (2373/2570, 92%) were mild with no loss of consciousness. CCP donors experienced lower rates of mild vasovagal events to new/returning whole blood donors overall but appear to be at higher risk after stratifying by sex and age. They are significantlymore likely to feel faint than new/returning apheresis donors. Differences between new/returning whole blood and CCP donors are statistically significant (p < 0.05) in both men and women in all age groups from 35 years upwards. In all cases where there is a significant difference, the rate was higher for CCP donors. When compared with new/returning apheresis donors, the rate in CCP donors was higher overall. One serious adverse event of donation was recorded in a new male CCP donor in his mid-40s who had severe immediate vasovagal reaction with hypotensive seizure requiring hospitalisation following his first CCP donation. He recovered subsequently and was withdrawn from donation. Donating CCP was largely safe but complications were seen following donation in 12% with vasovagal events, bruising and arm pain being the most reported donor adverse events. Vasovagal events could be multifactorial with increased anxiety, new/first time donors, vascular dysregulation or subclinical cardiac dysfunction secondary to recent COVID-19 infection possibly contributory. It is encouraging to see that the risk of having any adverse event halved with repeat donations.