Timing of last COVID-19 vaccine dose and SARS-CoV-2 breakthrough infections in fully (boosted) vaccinated healthcare personnel.

AIM: To estimate the incidence, timing and severity of severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) breakthrough infections in fully vaccinated healthcare personnel (HCP). METHODS: In total, 6496 fully vaccinated HCP were analysed prospectively from 15th November 2021 to 17th April 2022. Full coronavirus disease 2019 (COVID-19) vaccination was defined as a complete primary vaccination series followed by a booster dose at least 6 months later. RESULTS: Overall, 1845 SARS-CoV-2 breakthrough infections occurred (28.4 episodes per 100 HCP), of which 1493 (80.9%) were COVID-19 cases and 352 (19.1%) were asymptomatic infections. Of the 1493 HCP with COVID-19, four were hospitalized for 3-6 days (hospitalization rate among HCP with COVID-19: 0.3%). No intubations or deaths occurred. SARS-CoV-2 breakthrough infections occurred at a mean of 16.2 weeks after the last vaccine dose. Multi-variable regression analyses showed that among the 1845 HCP with a breakthrough infection, the administration of a COVID-19 vaccine dose ≥16.2 weeks before the infection was associated with increased likelihood of developing COVID-19 rather than asymptomatic SARS-CoV-2 infection [odds ratio (OR) 1.58, 95% confidence interval (CI) 1.01-2.46; P=0.045] compared with administering a vaccine dose later. The likelihood of developing COVID-19 compared with asymptomatic infection increased by 7% weekly after the last COVID-19 vaccine dose (OR 1.07, 95% CI 1.03-1.11; P=0.001). CONCLUSION: SARS-CoV-2 breakthrough infections are common among fully (boosted) vaccinated HCP. However, full COVID-19 vaccination offered considerable protection against hospitalization. These findings may contribute to defining the optimal timing for booster vaccinations. More efficient COVID-19 vaccines that will also confer protection against SARS-CoV-2 infection are needed urgently.

Costs associated with COVID-19 in healthcare personnel in Greece: a cost-of-illness analysis.

BACKGROUND: Healthcare personnel (HCP) are at increased risk of infection with severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2), the aetiological agent of coronavirus disease 2019 (COVID-19). AIM: To estimate the costs related to SARS-CoV-2 exposure and infection among HCP in Greece. METHODS: Data were retrieved from the national database of SARS-CoV-2 infections and from the database of HCP exposed to patients with COVID-19. A cost-of-illness analysis was performed to estimate total, direct and indirect costs. RESULTS: In total, 254 HCP with COVID-19 and 3332 HCP exposed to patients with COVID-19 during the first epidemic wave were studied. Of the 254 HCP with COVID-19, 49 (19.3%) were hospitalized (mean length of hospitalization 11.6 days) and four were admitted to intensive care units (mean duration 10.8 days). Overall, 1332 (40%) exposed HCP had a mean duration of absenteeism of 7.5 days, and 252 (99.2%) HCP with COVID-19 had a mean duration of absenteeism of 25.8 days. The total costs for the management of the two groups were estimated at €1,735,830 (€772,890 Euros for HCP with COVID-19 and €962,940 for exposed HCP). Absenteeism accounted for a large proportion of the total costs (80.4% of all expenditures), followed by costs for reverse transcriptase polymerase chain reaction and hospitalization (10.2% and 6.5% of all expenditures, respectively). CONCLUSION: COVID-19 is associated with increased rates and duration of absenteeism among HCP. Indirect costs, particularly absenteeism, are the major driver of total costs among exposed HCP and HCP with COVID-19. The estimated total costs are conservative. Studies are needed to explore the impact of COVID-19 vaccination of HCP on absenteeism and COVID-19-associated costs.