Widely heterogeneous humoral and cellular immunity after mild SARS-CoV-2 infection in a homogeneous population of healthy young men.

BACKGROUND: We studied humoral and cellular responses against SARS-CoV-2 longitudinally in a homogeneous population of healthy young/middle-aged men of South Asian ethnicity with mild COVID-19. METHODS: In total, we recruited 994 men (median age: 34 years) post-COVID-19 diagnosis. Repeated cross-sectional surveys were conducted between May 2020 and January 2021 at six time points - day 28 (n = 327), day 80 (n = 202), day 105 (n = 294), day 140 (n = 172), day 180 (n = 758), and day 280 (n = 311). Three commercial assays were used to detect anti-nucleoprotein (NP) and neutralizing antibodies. T cell response specific for Spike, Membrane and NP SARS-CoV-2 proteins was tested in 85 patients at day 105, 180, and 280. RESULTS: All serological tests displayed different kinetics of progressive antibody reduction while the frequency of T cells specific for different structural SARS-CoV-2 proteins was stable over time. Both showed a marked heterogeneity of magnitude among the studied cohort. Comparatively, cellular responses lasted longer than humoral responses and were still detectable nine months after infection in the individuals who lost antibody detection. Correlation between T cell frequencies and all antibodies was lost over time. CONCLUSION: Humoral and cellular immunity against SARS-CoV-2 is induced with differing kinetics of persistence in those with mild disease. The magnitude of T cells and antibodies is highly heterogeneous in a homogeneous study population. These observations have implications for COVID-19 surveillance, vaccination strategies, and post-pandemic planning.

Prevalence of urinary frequency among women aged 60 years and older in Taiwan.

OBJECTIVE: To evaluate the prevalence of daytime urinary frequency among Taiwanese women aged 60 years and older. MATERIALS AND METHODS: There were an estimated 1.25 million female residents aged 60 years and over in Taiwan in 2000. A sample of 2,410 women was selected using a multistage random sampling method. Face-to-face visits with 1,523 women were completed by trained professional interviewers within 3 months of the subjects selection. Questions about urinary frequency and other lower urinary tract symptoms, sociodemographics, reproduction, and medical and surgical histories were recorded. The factors were assessed by frequency and Pearson's Chi-squared test using a significance level of < 0.05. RESULTS: The prevalence of urinary frequency in Taiwanese women aged 60 years and over was 18.8% (286/1,521). The response rate was 85.0% (1,521/1,789). For those who complained of frequency, 45.8% voided 8-15 times a day, 37.8% voided 16-23 times a day, 1.7% voided 24-31 times and a day, and 14.7% voided more than 31 times a day. The prevalence of urinary frequency was significantly associated with age (p < 0.001). CONCLUSION: Urinary frequency is a common symptom in menopausal women and is significantly related to age. More than half of the women interviewed experienced intervals of < 1 hour between visits to the restroom during the day.