The durability of circulating neutralizing antibody (nAb) responses to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection and their boosting by vaccination remains to be defined. We show that outpatient and hospitalized SARS-CoV-2 seropositive individuals mount a robust neutralizing antibody (nAb) response that peaks at days 23 and 27 post-symptom onset, respectively. Although nAb titers remained higher in hospitalized patients, both study groups showed long-lasting nAb responses that can persist for up to 12 months after natural infection. These nAb responses in previously seropositive individuals can be significantly boosted through immunization with two doses of the CoronaVac (Sinovac) or one dose of the BNT162b2 (BioNTech/Pfizer) vaccines, suggesting a substantial induction of B cell memory responses. Noteworthy, three obese previously seropositive individuals failed to mount a booster response upon vaccination, warranting further studies in this population. Immunization of naïve individuals with two doses of the CoronaVac vaccine or one dose of the BNT162b2 vaccine elicited similar levels of nAbs compared to seropositive individuals 4.2 to 13.3 months post-infection with SARS-CoV-2. Thus, this preliminary evidence suggests that both, seropositive and naïve individuals, require two doses of CoronaVac to ensure the induction of robust nAb titers.

Andes virus (ANDV) is the leading cause of hantavirus cardiopulmonary syndrome (HCPS) in South America, a severe zoonosis with high mortality. Advances in critical care and extracorporeal membrane oxygenation (ECMO) have significantly improved survival rates; however, data on recovery beyond survival remain limited. This multicenter cohort study enrolled laboratory-confirmed HCPS survivors in Chile between 2021 and 2024, with follow-up at 3–6 months post-symptom onset to assess physical and neuropsychological sequelae. Participants were stratified by ECMO requirement and the clinical severity of HCPS, and evaluated using self-reported recovery, standardized symptom questionnaires, and EQ-5D quality-of-life instruments. Among 21 survivors (11 ECMO, 10 non-ECMO), 61.9% reported incomplete recovery. While 60–70% of patients received general medical follow-up, only 30% of non-ECMO patients—compared to all ECMO patients—had contact with a rehabilitation provider. Motor dysfunction and palpitations were more frequent in ECMO survivors; however, Jaccard index analysis revealed clustering of physical and neuropsychological symptoms across both groups. EQ-5D assessments showed comparable quality-of-life impairment, though non-ECMO survivors more often reported pain/discomfort (90.0% vs. 63.6%) and higher rates of analgesic self-medication. These findings highlight the burden of persistent symptoms after HCPS and the need for multidisciplinary post-discharge care in endemic regions.

Background: Coronavirus disease 2019 (COVID-19) caused by the severe acute respiratory syndrome virus (SARS-CoV-2) is challenging global public health, due to an increasing demand for testing and the shortage of diagnostic supplies. Nasopharyngeal swab (NPS) is considered the optimal sample for SARS-CoV2 diagnosis and sputum (SPT) has been proposed as an economic alternative. However, the temporal concordance of diagnosis in NPS and SPT has not been addressed. Methods: Through a longitudinal study we compared the shedding dynamics of SARS-CoV-2 RNA evaluated by RT-qPCR in serially collected SPT and NPS obtained from 82 ambulatory and hospitalized patients during acute infection and convalescence. The concordance during the follow-up and cost analysis between both collected specimens was evaluated. Findings: We analyzed 379 samples, 177 NPS and 202 SPT. The highest proportion of positive samples was detected within the first 15 days after the symptoms onset. The median time of positivity was higher for NPS (median= 25 days) than SPT (median= 21 days). There was no significant difference in the median RT-qPCR C _T values between both sample types. The temporal categorization of matched-paired samples indicated substantial correlation (r=0·6023) and substantial agreement (87·23%) during the first ten days since symptoms onset (kappa = 0·697). A cost analysis demonstrated a significant saving when the SPT specimen was used. Interpretation: Sputum is a feasible and cost-saving alternative to NPS, providing an equivalent value for the detection and follow-up of SARS-CoV-2 RNA. Funding: Agencia Nacional de Investigación y Desarrollo (ANID) of Chile, NIH-NIAID USA.

Actualmente y no en pocas ocasiones, al sarampión se le considera una enfermedad benigna, aunque esto no siempre fue así, a modo de ejemplo, en Santiago de Chile a comienzos del siglo XX, miles de niños fallecían por epidemias de “alfombrilla”. Comunicaciones nacionales daban cuenta de sus frecuentes complicaciones, muchas de ellas de carácter letal. Estos hallazgos históricos ilustran la magnitud de la carga sanitaria del sarampión en la era pre-vacunas. A inicios de la década del sesenta se inició el programa de vacunación contra el sarampión en la provincia de Santiago, continuando los meses siguientes en el resto del país, siendo esta la primera experiencia mundial de carácter nacional. En 1992 se logró la interrupción de la transmisión autóctona de la infección. En la actualidad el sarampión se está propagando debido a la reducción de su cobertura de vacunación, principalmente ocasionada por la interrupción de los programas locales de inmunización y a la existencia de grupos con baja adherencia o resistencia a la vacunación. El objetivo de esta comunicación es revisar las principales comunicaciones de Revista Chilena de Pediatría referentes a las graves complicaciones ocasionadas por el sarampión durante el siglo pasado.