key: cord-0706281-erw4i5gu
authors: Alicandro, Gianfranco; Daccó, Valeria; Cariani, Lisa; Contarini, Martina; Morlacchi, Letizia Corinna; Rosazza, Chiara; Sciarrabba, Calogero Sathya; Ferraro, Federica; Lanfranchi, Chiara; Orena, Beatrice Silvia; Gramegna, Andrea; Blasi, Francesco; Colombo, Carla
title: Safety of mRNA-based vaccines against SARS-CoV-2 in people with cystic fibrosis aged 12 years and over
date: 2022-02-16
journal: J Cyst Fibros
DOI: 10.1016/j.jcf.2022.02.009
sha: ef79cb2ba50bfe177b6e8237e7644b9fab132f82
doc_id: 706281
cord_uid: erw4i5gu

nan

Adverse reactions following the administration of mRNA-based vaccines against SARS-CoV-2 indicate acceptable safety profiles with recipients complaining mostly of local reactions which resolve in a few days [1] . However, mild forms of myocarditis and pericarditis also resolving without sequalae were reported in around 4 cases per 100,000 young males vaccinated and 0.5 per 100,000 women [2] . Severe reactions, including anaphylaxis, were rarely observed (less than 5 people per million vaccinated) mainly among women and individuals with a history of clinical allergy [3] .

People affected by cystic fibrosis (pwCF), were among the first to receive anti-SARS-CoV-2 vaccines in several countries including Italy, due to their risk of developing severe Covid-19.

However, there are no data on the safety of mRNA-based vaccines against SARS-CoV-2 in pwCF.

Therefore, we conducted a study aimed at evaluating the reactogenicity and safety of these vaccines in pwCF.

All patients aged ≥12 years, in regular follow-up at the paediatric and adult CF centres of the Patients were subsequently interviewed by the attending physician of their CF centre in order to complete a diary card recording solicited local and systemic adverse reactions for 7 days after each administration. Severity of adverse reactions was graded using the following criteria: mild (transient or mild discomfort for <48 h, no interference with activity, and no medical intervention or therapy required), moderate (mild-to-moderate limitation in activity, and no or minimal medical intervention or therapy required), severe (substantial limitation in activity and medical intervention or therapy required), or potentially life-threatening (requiring assessment in emergency department or admission to hospital) [4] . All adverse events, even those apparently Most adverse reactions after both vaccine doses were considered of mild severity, while 94 (22.2%) reactions of moderate severity were reported after the first dose and 132 (31.1%) after the second dose. No significant differences were detected across age groups, transplant status, respiratory function categories, oxygen therapy and history of Covid-19 (Supplementary table S1) .

Despite the large imbalance between the number of patients receiving mRNA-1273 (N=45) and

BNT162b2 vaccine (N=379), we did not observe less reactogenicity of BNT162b2, which in contrast was reported by the US surveillance system v-safe [1] , based on more than 3.6 million vaccine recipients. In fact, in our study the frequency and severity of adverse reactions to the first injection were similar between the two vaccines, while fewer adverse reactions were reported after the second injection of mRNA-1273 (local: 69.0% vs. 76.7%, systemic: 45.2% vs 62.1%), although the differences were not statistically significant (Supplementary table S2) .

Our population included three patients with a history of severe anaphylactic reactions who received the vaccine in a protected environment and did not experience any severe reaction.

An acute coronary syndrome (ACS) episode was observed after 8 days from the second dose, in a patient aged 50 years with diabetes and hypertension who had a previous ACS in 2012. Given the pre-existing conditions, this event was considered unlikely related to the vaccine.

As of November 2021, we did not register any case of myocarditis or pericarditis as well as any anaphylactic reaction or other solicited adverse events. However, although including a relatively large number of patients, our study is not adequately powered to evaluate these rare events.

Moreover, our results are limited to subject aged ≥12 years and to two doses of vaccine since at the time of the study vaccines were not yet approved for younger children and the booster dose was not available.

Despite these limitations, this is the first work reporting on the safety of mRNA vaccines in a relatively large group of pwCF basically confirming what has been documented in the general population [1] . However, local reactions after the first dose were more frequently reported in our CF population as compared to what has been registered in the US surveillance data (82.8% vs 65.4% for the BNT162b2 vaccine) and the proportions of main systemic reactions were slightly lower after either the first or second dose [1] . In particular, fatigue was reported by 17.5% of our pwCF after the first dose and by 25.8% after the second dose, while corresponding figures observed in the US general population were 29.1% and 47.8%, respectively.

In conclusion, our results indicate that mRNA vaccines for pwCF are well-tolerated and safe in the short-term. Thus, the benefit of preventing severe Covid-19 outweigh the complains related to the mild-to-moderate adverse reactions observed.

Funding: none. 

Reactogenicity following receipt of mrna-based covid-19 vaccines

Myocarditis after Covid-19 Vaccination in a Large Health Care Organization

Reports of Anaphylaxis after Receipt of mRNA COVID-19

Safety and Efficacy of the BNT162b2 mRNA Covid-19 Vaccine