ABSTRACT
The post-acute phase of SARS-CoV-2 infection was investigated in rhesus (Macaca mulatta) and cynomolgus macaques (Macaca fascicularis). During the acute phase of infection, SARS-CoV-2 was shed via the nose and throat, and viral RNA was occasionally detected in feces. This phase coincided with a transient change in systemic immune activation. Even after the alleged resolution of the infection, computed tomography (CT) and positron emission tomography (PET)-CT revealed pulmonary lesions and activated tracheobronchial lymph nodes in all animals. Post-mortem histological examination of the lung tissue revealed mostly marginal or resolving minimal lesions that were indicative of SARS-CoV-2 infection. Evidence for SARS-CoV-2-induced histopathology was also found in extrapulmonary tissue samples, such as conjunctiva, cervical, and mesenteric lymph nodes. However, 5-6 weeks after SARS-CoV-2 exposure, upon necropsy, viral RNA was still detectable in a wide range of tissue samples in 50% of the macaques and included amongst others the heart, the respiratory tract and surrounding lymph nodes, salivary gland, and conjunctiva. Subgenomic messenger RNA was detected in the lungs and tracheobronchial lymph nodes, indicative of ongoing virus replication during the post-acute phase. These results could be relevant for understanding the long-term consequences of COVID-19 in humans.
Subject(s)
COVID-19/pathology , COVID-19/virology , Lung/pathology , SARS-CoV-2/physiology , Animals , Antibodies, Viral/blood , COVID-19/immunology , Cytokines/blood , Disease Models, Animal , Humans , Lung/virology , Lymph Nodes/pathology , Lymph Nodes/physiopathology , Macaca fascicularis , Macaca mulatta , RNA, Messenger/analysis , RNA, Viral/analysis , Respiratory System/pathology , Respiratory System/virology , SARS-CoV-2/immunology , Virus ReplicationABSTRACT
A key unsolved question in the current coronavirus disease 2019 (COVID-19) pandemic is the duration of acquired immunity. Insights from infections with the four seasonal human coronaviruses might reveal common characteristics applicable to all human coronaviruses. We monitored healthy individuals for more than 35 years and determined that reinfection with the same seasonal coronavirus occurred frequently at 12 months after infection.
Subject(s)
Adaptive Immunity/physiology , COVID-19 , Coronavirus Infections/immunology , Coronavirus/immunology , Reinfection/immunology , Seasons , Adolescent , Adult , Aged , Aged, 80 and over , COVID-19/blood , COVID-19/epidemiology , COVID-19/immunology , COVID-19/prevention & control , Cohort Studies , Coinfection/blood , Coinfection/epidemiology , Coronavirus/genetics , Coronavirus Infections/blood , Coronavirus Infections/epidemiology , Coronavirus Infections/virology , Follow-Up Studies , HIV Infections/complications , HIV Infections/epidemiology , Humans , Male , Middle Aged , Netherlands/epidemiology , Pandemics , RNA, Viral/analysis , RNA, Viral/blood , Reinfection/blood , Reinfection/epidemiology , Reinfection/virology , SARS-CoV-2/genetics , SARS-CoV-2/immunology , Serologic Tests/methods , Time Factors , Young AdultABSTRACT
Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has infected more than 8 million people worldwide, becoming a pandemic. Detecting antibodies against SARS-CoV-2 is of utmost importance and a good indicator of exposure and circulation of the virus within the general population. Two serological tools based on a double recognition assay [enzyme-linked immunosorbent assay (DR-ELISA) and lateral flow assay (DR-LFA)] to detect total antibodies to SARS-CoV-2 have been developed based on the recombinant nucleocapsid protein. A total of 1065 serum samples, including positive for COVID-19 and negative samples from healthy donors or infected with other respiratory pathogens, were analyzed. The results showed values of sensitivity between 91.2% and 100%, and specificity of 100% and 98.2% for DR-LFA and DR-ELISA, respectively. No cross-reactivity against seasonal coronavirus (HCoV-NL63, HCoV-229E, HCoV-HKU1, HCoV-OC43) was found. These results demonstrate the importance of serology as a complementary tool to polymerase chain reaction for follow-up of recovered patients and identification of asymptomatic individuals.