Faster decay of neutralizing antibodies in never infected than previously infected healthcare workers three months after the second BNT162b2 mRNA COVID-19 vaccine dose.

OBJECTIVES: This study aimed to describe the longitudinal evolution of neutralizing antibody titres (NtAb) in three different cohorts of healthcare workers (HCWs), including vaccinated HCWs with and without a previous SARS-CoV-2 infection and previously infected unvaccinated HCWs. COVID-19 was mild or asymptomatic in those experiencing infection. METHODS: NtAb was tested before BNT162b2 mRNA COVID-19 vaccine (V0), 20±2 days after the first dose (V1_20), 20±3 days (V2_20) and 90±2 days (V2_90) after the second dose in vaccinated HCWs and after about 2 months (N_60), 10 months (N_300) and 13 months (N_390) from natural infection in unvaccinated HCWs. NtAb were measured by authentic virus neutralization with a SARS-CoV-2 B.1 isolate circulating in Italy at HCW enrolment. RESULTS: Sixty-two HCWs were enrolled. NtAb were comparable in infected HCWs with no or mild disease at all the study points. NtAb of uninfected HCWs were significantly lower with respect to those of previously infected HCWs at V1_20, V2_20 and V2_90. The median NtAb fold decrease from V2_20 to V2_90 was higher in the uninfected HCWs with respect to those with mild infection (6.26 vs 2.58, p=0.03) and to asymptomatic HCWs (6.26 vs 3.67, p=0.022). The median Nabt at N_390 was significantly lower than at N_60 (p=0.007). CONCLUSIONS: In uninfected HCWs completing the two-dose vaccine schedule, a third mRNA vaccine dose is a reasonable option to counteract the substantial NtAb decline occurring at a significantly higher rate compared with previously infected, vaccinated HCWs. Although low, Nabt were still at a detectable level after 13 months in two-thirds of previously infected and unvaccinated HCWs.

Time Course of Neutralizing Antibody in Health Care Workers With Mild or Asymptomatic COVID-19 Infection.

We describe the time course of neutralizing antibody (NtAb) titer in a cohort of health care workers with mild or asymptomatic severe acute respiratory syndrome coronavirus (SARS-CoV-2) infection. NtAb levels decreased over time; however, serum neutralizing activity remained detectable after a median of 7 months from SARS-CoV-2 diagnosis in the majority of cases.

Objective and subjective clinical effects of a Nd:YAG 532-nm frequency-doubled long-pulsed diode pumped laser system on photoaging of the face: a retrospective study on color signs, texture and rhytids.

BACKGROUND: Pulsed 532-nm lasers have been widely used in the treatment of vascular and pigmented conditions of aged skin. In addition to lesion clearance, many patients report color and texture improvements to the skin. These improvements are often difficult to appreciate from photographic analysis alone, but are significant to the patient's impression of treatment success. OBJECTIVE: To grade and compare objective and subjective results of treatments with a 532-nm frequency-doubled pulsed Nd:YAG laser using criteria of skin color, skin texture, and wrinkles based on a blinded retrospective analysis of photographs compared with results from patient questionnaires. METHODS: Clinical before and after pictures from 20 patients (skin types I-IV) treated for diffuse vascular and pigmented lesions were selected for evaluation. A blinded grading was performed using criteria of skin color, skin texture, and wrinkles. Patients were asked by questionnaire to also grade improvement using the same criteria. The results of the blinded and patient grading were reported and compared using a chi-squared analysis. RESULTS: Clinical improvements recorded by blinded photographic evaluation and patient evaluation agreed with no statistically significant differences. Both the blinded observers and patients recorded remarkable improvement in the color signs of photoaging, slight to moderate improvement in skin texture and fine wrinkles, and negligible improvement of medium depth and deep wrinkles. CONCLUSION: The 532-nm pulsed laser is a safe and effective device for the treatment of the visible signs of photoaging of skin types I-III. In addition to improvements in color defects, objectively and subjectively significant improvements in texture and fine wrinkles can be expected. Little to no improvement in medium to deep wrinkles can be anticipated.