ABSTRACT
In February 2021, Peru launched a vaccination campaign among healthcare personnel using BBIBP-CorV inactivated whole virus (BBIBP-CorV) COVID-19 vaccine. Two doses of BBIBP-CorV vaccine are recommended, 21 days apart. Data on BBIBP-CorV vaccine effectiveness will inform the use and acceptance of vaccination with BBIBP-CorV vaccine. We evaluated BBIBP-CorV vaccine effectiveness among an existing multi-year influenza cohort at two hospitals in Lima. We analyzed data on 290 participants followed between February and May 2021. Participants completed a baseline questionnaire and provided weekly self-collected anterior nasal swabs tested for SARS-CoV-2 by rRT-PCR for sixteen weeks. We performed multivariable logistic regression models adjusting for pre-selected characteristics (age, sex, exposure to COVID-19 patients, work in intensive care unit or emergency department, BMI, and exposure time in days). BBIBP-CorV vaccine effectiveness was calculated after the two-week post-vaccination period as (1-Odds Ratio for testing SARS-CoV-2 positive)x100%. SARS-CoV-2 was detected by rRT-PCR among 25 (9%) participants during follow-up (February-May 2021). Follow-up period ranged 1-11 weeks (median: 2 weeks). Among cohort participants who were fully vaccinated the adjusted vaccine effectiveness against SARS-CoV-2 infection was estimated as 95% (95% CI: 70%, 99%) and 100% (95% CI: 88%, 100%) for those partially vaccinated. During the study period, vaccination of healthcare personnel with BBIBP-CorV vaccine was effective at reducing SARS-CoV-2 infections in the weeks immediately following vaccination. This information can be used to support vaccination efforts in the region, especially among those who could be concerned about their effectiveness.
ABSTRACT
BackgroundIn early 2020, an outbreak of coronavirus disease 2019 occurred among passengers and crew of the Diamond Princess cruise ship. During February 16-17, some US citizens, residents, and their partners voluntarily repatriated to the US from Japan. MethodsWe conducted a retrospective, longitudinal evaluation of repatriated travelers where the outcome of interest was a positive test for SARS-CoV-2. Travelers who tested positive for SARS-CoV-2 were isolated in hospitals or at home under county isolation orders and underwent serial testing by real-time reverse transcription polymerase chain reaction (RT-PCR) approximately every other day, as contemporaneous US guidance required two consecutive negative tests collected [≥]24 hours apart and symptom improvement before release from isolation. ResultsAmong quarantined repatriated travelers, 14% tested positive for SARS-CoV-2. One-fifth of infected travelers initially tested negative but were identified on subsequent testing. All infected travelers remained asymptomatic or developed mild symptoms during isolation. Many travelers remained in prolonged isolation because of persistent viral detection based on contemporaneous policies. ConclusionOur findings support testing within 3-5 days after possible SARS-CoV-2 exposure to comprehensively identify infections and mitigate transmission and lend support to symptom- and time-based isolation recommendations, rather than test-based criteria.
ABSTRACT
BackgroundCoronavirus disease 2019 (COVID-19), the respiratory disease caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), was first identified in Wuhan, China and has since become pandemic. As part of initial response activities in the United States, enhanced contact investigations were conducted to enable early identification and isolation of additional cases and to learn more about risk factors for transmission. MethodsClose contacts of nine early travel-related cases in the United States were identified. Close contacts meeting criteria for active monitoring were followed, and selected individuals were targeted for collection of additional exposure details and respiratory samples. Respiratory samples were tested for SARS-CoV-2 by real-time reverse transcription polymerase chain reaction (RT-PCR) at the Centers for Disease Control and Prevention. ResultsThere were 404 close contacts who underwent active monitoring in the response jurisdictions; 338 had at least basic exposure data, of whom 159 had [≥]1 set of respiratory samples collected and tested. Across all known close contacts under monitoring, two additional cases were identified; both secondary cases were in spouses of travel-associated case patients. The secondary attack rate among household members, all of whom had [≥]1 respiratory sample tested, was 13% (95% CI: 4 - 38%). ConclusionsThe enhanced contact tracing investigations undertaken around nine early travel-related cases of COVID-19 in the United States identified two cases of secondary transmission, both spouses. Rapid detection and isolation of the travel-associated case patients, enabled by public awareness of COVID-19 among travelers from China, may have mitigated transmission risk among close contacts of these cases.
ABSTRACT
IntroductionMore than 93,000 cases of coronavirus disease (COVID-19) have been reported worldwide. We describe the epidemiology, clinical course, and virologic characteristics of the first 12 U.S. patients with COVID-19. MethodsWe collected demographic, exposure, and clinical information from 12 patients confirmed by CDC during January 20-February 5, 2020 to have COVID-19. Respiratory, stool, serum, and urine specimens were submitted for SARS-CoV-2 rRT-PCR testing, virus culture, and whole genome sequencing. ResultsAmong the 12 patients, median age was 53 years (range: 21-68); 8 were male, 10 had traveled to China, and two were contacts of patients in this series. Commonly reported signs and symptoms at illness onset were fever (n=7) and cough (n=8). Seven patients were hospitalized with radiographic evidence of pneumonia and demonstrated clinical or laboratory signs of worsening during the second week of illness. Three were treated with the investigational antiviral remdesivir. All patients had SARS-CoV-2 RNA detected in respiratory specimens, typically for 2-3 weeks after illness onset, with lowest rRT-PCR Ct values often detected in the first week. SARS-CoV-2 RNA was detected after reported symptom resolution in seven patients. SARS-CoV-2 was cultured from respiratory specimens, and SARS-CoV-2 RNA was detected in stool from 7/10 patients. ConclusionsIn 12 patients with mild to moderately severe illness, SARS-CoV-2 RNA and viable virus were detected early, and prolonged RNA detection suggests the window for diagnosis is long. Hospitalized patients showed signs of worsening in the second week after illness onset.
