Early High-Titer Plasma Therapy to Prevent Severe Covid-19 in Older Adults.

BACKGROUND: Therapies to interrupt the progression of early coronavirus disease 2019 (Covid-19) remain elusive. Among them, convalescent plasma administered to hospitalized patients has been unsuccessful, perhaps because antibodies should be administered earlier in the course of illness. METHODS: We conducted a randomized, double-blind, placebo-controlled trial of convalescent plasma with high IgG titers against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in older adult patients within 72 hours after the onset of mild Covid-19 symptoms. The primary end point was severe respiratory disease, defined as a respiratory rate of 30 breaths per minute or more, an oxygen saturation of less than 93% while the patient was breathing ambient air, or both. The trial was stopped early at 76% of its projected sample size because cases of Covid-19 in the trial region decreased considerably and steady enrollment of trial patients became virtually impossible. RESULTS: A total of 160 patients underwent randomization. In the intention-to-treat population, severe respiratory disease developed in 13 of 80 patients (16%) who received convalescent plasma and 25 of 80 patients (31%) who received placebo (relative risk, 0.52; 95% confidence interval [CI], 0.29 to 0.94; P = 0.03), with a relative risk reduction of 48%. A modified intention-to-treat analysis that excluded 6 patients who had a primary end-point event before infusion of convalescent plasma or placebo showed a larger effect size (relative risk, 0.40; 95% CI, 0.20 to 0.81). No solicited adverse events were observed. CONCLUSIONS: Early administration of high-titer convalescent plasma against SARS-CoV-2 to mildly ill infected older adults reduced the progression of Covid-19. (Funded by the Bill and Melinda Gates Foundation and the Fundación INFANT Pandemic Fund; Dirección de Sangre y Medicina Transfusional del Ministerio de Salud number, PAEPCC19, Plataforma de Registro Informatizado de Investigaciones en Salud number, 1421, and ClinicalTrials.gov number, NCT04479163.).

Community Mortality Due to Respiratory Syncytial Virus in Argentina: Population-based Surveillance Study.

BACKGROUND: Many deaths in infants from low-middle income countries (LMICs) occur at home or upon arrival to health facilities. Although acute lower respiratory tract illness plays an important role in community mortality, the accuracy of mortality rates due to respiratory syncytial virus (RSV) remains unknown. METHODS: An active surveillance study among children aged under 5 years old (U5) was performed in Buenos Aires, Argentina, between January and December 2019, to define the burden and role of RSV in childhood community mortality. RESULTS: A total of 63 families of children U5 participated in the study. Based on a combined approach of tissue sampling, verbal autopsies, and expert's analysis, RSV infection was found in the causal chain of 11 from 12 cases with positive molecular biology results in respiratory samples. The estimated mortality rate due to RSV among infants was 0.27 deaths/1000 live births. The mean age of RSV-related household deaths was 2.8 months of age (standard deviation [SD] 1.7), and 8/12 were male infants (66.7%). Dying at home from RSV was associated with Streptococcus pneumoniae and/or Moraxella catarrhalis lung coinfection (75%), living in slums and settlement (odds ratio [OR], 17.09; 95% confidence interval [CI], 1.3-219.2), and other underlying comorbidities (OR, 14.87; 95% CI, 1.3-164.6). CONCLUSIONS: Infant community mortality rates due to RSV are higher than those reported in industrialized countries and similar to those reported in hospital-based studies in the same catchment population.

The long road to protect infants against severe RSV lower respiratory tract illness.

Severe respiratory syncytial virus (RSV) lower respiratory tract illness (LRTI) in infants has proven challenging to prevent. In the last 50 years, conceptually different approaches failed to evolve into viable preventive alternatives for routine use. Inactivated RSV vaccine (that is, formalin-inactivated RSV) elicited severe LRTI in RSV-infected toddlers pre-immunized as infants; early purified F protein approaches in pregnant women failed to elicit sufficient immunity more than a decade ago; a second-generation monoclonal antibody (mAb) of high potency against the virus (that is, motavizumab) caused severe adverse reactions in the skin, and owing to lack of efficacy against RSV subgroup B, an extended half-life mAb targeting site V in the RSV fusion protein (that is, REG2222) did not meet its primary endpoint. In the meantime, two protein F vaccines failed to prevent medically attended LRTI in the elderly. However, palivizumab and the recent results of the Novavax maternal immunization trial with ResVax demonstrate that severe RSV LRTI can be prevented by mAb and by maternal immunization (at least to a certain extent). In fact, disease prevention may also decrease the rates of recurrent wheezing and all-cause pneumonia for at least 180 days. In this review, we discuss the history of RSV vaccine development, previous and current vaccine strategies undergoing evaluation, and recent information about disease burden and its implications for the effects of successful preventive strategies.