Viral dynamics of SARS-CoV-2 Omicron infections in a previously low COVID-19 prevalence region: Effects of vaccination status, antiviral agents, and age

Seroprevalence of SARS-CoV-2 in self-reported COVID-19-free children

INTRODUCTION

COVID-19 poses risks and leads to complications for vulnerable populations, including children. Unreported cases of COVID-19 among children hinder our understanding of the true disease burden. In this study, we aimed to investigate the proportion of children who report no prior infection to SARS-CoV-2 but who nevertheless exhibit serological evidence of prior infection.

METHODS

Between November 2022 and February 2023, we recruited children and adolescents under 19 years of age who lacked a prior history of SARS-CoV-2 infection. Participants underwent SARS-CoV-2 antibody testing to assess the presence of IgG antibodies specific to nucleocapsid (N) and spike (S) proteins. Demographic and contact information were also collected.

RESULTS

Among 260 COVID-19-free children, the overall anti-N antibody positivity rate, which varied across age groups (4%-25%), was 9.2% (24/260). Contact with individuals who were positive for COVID-19, particularly the children's mothers, significantly increased the likelihood of antibody positivity. The median age of the 34 children who remained unvaccinated against COVID-19 was lower than that of the children who were vaccinated (6.5 vs. 9 years; p < 0.001). Until January 2024, the overall infection rate was 41.9% (99/236) among children who were negative for anti-N antibodies, irrespective of vaccination status or the presence of chronic disease.

CONCLUSION

We discovered previously undisclosed cases of SARS-CoV-2 infection among children. The risk of seropositivity increases substantially with household contact. Regarding children who report no prior exposure to COVID-19, clinicians must remain vigilant, as SARS-CoV-2 remains a concern.

Monocentric study of IL-5 monoclonal antibody induction therapy for eosinophilic granulomatosis with polyangiitis

OBJECTIVE

Although sporadic case reports have demonstrated successful management of eosinophilic granulomatosis with polyangiitis (EGPA) by anti-IL-5 therapy, larger-scale monocentric studies for the efficacy of mepolizumab (MEP), an IL-5 monoclonal antibody, are still lacking in Taiwan.

METHODS

Hospitalized EGPA patients aged at least 18 years were enrolled from November 1998 to October 2023, and analyzed for demographic, clinical, laboratory, medication and outcome data, focusing on the efficacy and safety of biologics use, particularly induction therapy with MEP.

RESULTS

Twenty-seven EGPA patients aged 10-70 years (43 ± 15) at disease diagnosis were recruited with 21 under combined corticosteroids/cyclophosphamide induction therapy. Seventeen patients received biologics with 13 under MEP therapy. Ten patients aged 19-71 years (48 ± 15) completed 12-month induction therapy with a 100 mg quadri-weekly subcutaneous injection regimen indicated for active or relapse disease. There were reduced BVAS with complete remission in 6 and partial remission in 4 patients, lower CRP levels, decreased eosinophil counts with an inhibition of 92∼96 %, and tapered prednisolone dosages from 5 to 25 (13.0 ± 6.3) to 0-10 (3.3 ± 3.1) mg/day. Only one patient had an adverse event of injection site reactions. Nine patients received the same regimen for annual maintenance therapy. All had a persistent clinical remission. In these patients, 13-56 injections (41 ± 15) were prescribed with a follow-up period of 12∼52 months (38 ± 14).

CONCLUSION

In this retrospective study, induction therapy with a 12-month 100 mg MEP quadri-weekly subcutaneous injection regimen demonstrates the efficacy and safety for active and relapsing EGPA patients.