The outbreak of coronavirus disease 2019 (COVID-19) has distressed our working practice. Infectious disease specialists, pneumologists and intensivists were not enough to face the enormous amount of patients that needed hospital care; therefore, many doctors have been recruited from other medical specialties trying to take care of as many patients as possible. The 'call to duty' of such doctors for urgent COVID-19 cases, however, diverted the attention from the care of patients with chronic conditions, which might have been neglected or undervalued. In this extremely difficult time, the standard of care of chronic patients has been reduced and this might have determined an increased rate of complications secondary to undermanagement. Thousands of patients with acute and chronic non-COVID-19 conditions have not accessed specialist care in the last weeks in Italy. Moreover, even those patients who have had scheduled an outpatient visit did not attend it for fear of leaving their home or due to the inability to go. During the pandemic, there was a drastic reduction in the number of hospital admissions for any medical conditions different from COVID-19. Self-presentation to the emergency department (ED) has been discouraged and the patients' own fear of being infected by going to the hospital led to also a significant decrease in ED access. During the lockdown, in San Giuseppe Hospital MultiMedica IRCCS, Milan, the ED admissions dropped from the mean of 2361/ month in December 2019-February 2020 to 1102 (− 53%) and 861 (− 63%) in March and April 2020, respectively. For all the above-mentioned reasons, it is possible that some clinical conditions will further progress with a significant increase in morbidity and mortality. To prevent this, it is essential that patients with chronic conditions should be at least monitored and managed with telephone or online health consultation, identifying those who need urgent access to care, prioritizing outpatient visits based on disease severity. Patients with mild conditions could be managed outside the hospital by implementing telemedicine and creating networks of general practitioners who can consult with in-hospital specialists. Keywords Chronic disease • COVID-19 • SARS-CoV-2 • Emergency department Newly identified SARS CoV-2 may cause mild and selflimiting illness with upper respiratory tract symptoms,

Objectives The aim of this study was to investigate the possible impact of smoking on the humoral response to the BNT162b2 mRNA COVID-19 vaccine (also known as the BioNTech-Pfizer COVID-19 vaccine). Study design A longitudinal sero-epidemiological study was conducted in sample of Italian healthcare workers (HCWs). Methods HCWs who were administered two doses of the BNT162b2 mRNA vaccine, 21 days apart, between December 2020 and January 2021, were invited to undergo multiple serology tests to identify SARS-CoV-2 S-RBD-specific immunoglobulin G (IgG) antibodies. Participants also responded to questions about their smoking status (i.e. current smokers vs non-smokers) in a survey. Results Sixty days after the completion of the vaccination cycle, serological analyses showed a difference in vaccine-induced IgG titre between current smokers and non-smokers, with median antibody titres of 211.80 AU/mL (interquartile range [IQR] 149.80–465.50) and 487.50 AU/mL (IQR 308.45–791.65) [ P -value = 0.002], respectively. This significant difference in vaccine-induced IgG titres between current smokers and non-smokers remained after adjusting for age, sex, and previous infection with SARS-CoV-2. Conclusions This study observed that vaccine-induced antibody titres decrease faster among current smokers than non-smokers. Further research to investigate the impact of smoking on the immunological response to COVID-19 and non-COVID-19 vaccines is required.

Sero-epidemiological surveys are valuable attempts to estimate the circulation of SARS-CoV-2 in general or selected populations. Within this context, a prospective observational study was conducted to estimate the prevalence and persistence of SARS-CoV-2 antibodies in different categories of workers and factors associated with positivity, through the detection of virus-specific immunoglobulin G and M (IgG/IgM) in serum samples. Enrollees were divided in low exposure and medium-high groups on the basis of their work activity. Antibody responders were re-contacted after 3 months for the follow-up. Of 2255 sampled workers, 4.8% tested positive for SARS-CoV-2 IgG/IgM antibodies, with 81.7% to IgG only. Workers who continued to go to their place of work, were healthcare workers, or experienced at least one COVID-19-related symptom were more likely to test positive for SARS-CoV-2 antibodies. SARS-CoV-2 antibodies prevalence was significantly higher in the medium-high risk vs. low-risk group (7.2% vs. 3.0%, p < 0.0001). At 3-month follow-up, 81.3% of subjects still had antibody response. This study provided important information of SARS-CoV-2 infection prevalence among workers in northern Italy, where the impact of COVID-19 was particularly intense. The presented surveillance data give a contribution to refine current estimates of the disease burden expected from the SARS-CoV-2.