Impact of prior infection status on antibody response to the BNT162b2 mRNA COVID-19 vaccine in healthcare workers at a COVID-19 referral hospital in Milan, Italy.

In Italy, SARS-CoV-2 vaccination campaign prioritized healthcare workers (HCWs) to receive two doses of BNT162b2 vaccine, irrespective of a previous SARS-CoV-2 infection. In this real-life study, we compared the humoral response to BNT162b2 vaccine in HCWs with and without a previous SARS-CoV-2 infection. Of the 407 HCWs enrolled, 334 (82.1%) were SARS-CoV-2-naive and 73 (17.9%) SARS-CoV-2-experienced. Post-vaccine humoral response was detectable in more than 98% of HCWs. Overall, the median level of anti-S IgG in SARS-COV-2-experienced HCWs was twice as high as those of SARS-CoV-2-naive subjects (24641.0 AU/mL [IQR: 15273.0->40000.0] versus 13053.8 [IQR: 7303.3-20105.8]; p < .001), irrespective of the time elapsed from SARS-CoV-2 previous infection. In a subgroup of SARS-CoV-2-naive and -experienced subjects who received only one dose of the vaccine, the latter showed 32 times higher levels of anti-S IgG compared to the former. Although no serious adverse events have been reported, mild to moderate side effects occurred more frequently after the first dose in the SARS-CoV-2-experienced than in naive subjects (67% versus 42%, respectively; p < .001). Notably, post-vaccination anti-SARS-CoV-2 spike IgG levels ≥20,000 AU/mL were independently associated with the risk of fever ≥38°C (adjusted odds ratio [aOR] 5.122, 95% CI 2.368-11.080, p < .0001).Our study showed high responsiveness of BNT162b2 vaccine and a relationship between levels of antibody response and reactogenicity. It suggests that a single dose of mRNA vaccine might evoke effective protection in SARS-CoV-2-experienced subjects.

Drug-Drug Interactions and Prescription Appropriateness at Hospital Discharge: Experience with COVID-19 Patients.

BACKGROUND: Patients with coronavirus disease 2019 (COVID-19) are often elderly, with comorbidities, and receiving polypharmacy, all of which are known factors for potentially severe drug-drug interactions (DDIs) and the prescription of potentially inappropriate medications (PIMs). OBJECTIVE: The aim of this study was to assess the risk of DDIs and PIMs in COVID-19 patients at hospital discharge. METHOD: Patients with a proven diagnosis of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection who were hospitalized between 21 February and 30 April 2020, treated with at least two drugs, and with available information regarding pharmacological treatments upon admission and at discharge were considered. The appropriateness of drug prescriptions was assessed using INTERcheck®. RESULTS: A significant increase in the prescription of proton pump inhibitors and heparins was found when comparing admission with hospital discharge (from 24 to 33% [p < 0.05] and from 1 to 17% [p < 0.01], respectively). The increased prescription of heparins at discharge resulted in a highly significant increase in the potentially severe DDIs mediated by this class of drugs. 51% of COVID-19 patients aged > 65 years had at least one PIM upon admission, with an insignificant increment at discharge (58%). CONCLUSION: An increased number of prescribed drugs was observed in COVID-19 patients discharged from our hospital. The addition of heparins is appropriate according to the current literature, while the use of proton pump inhibitors is more controversial. Particular attention should be paid to the risk of bleeding complications linked to heparin-based DDIs.