ABSTRACT
Both vector and mRNA vaccines were an important part of the response to the COVID-19 pandemic and may be required in future outbreaks and pandemics. However, adenoviral vectored (AdV) vaccines may be less immunogenic than mRNA vaccines against SARS-CoV-2. We assessed anti-spike and anti-vector immunity among infection-naive Health Care Workers (HCW) following two doses of AdV (AZD1222) versus mRNA (BNT162b2) vaccine. 183 AdV and 274 mRNA vaccinees enrolled between April and October 2021. Median ages were 42 and 39 years, respectively. Blood was collected at least once, 10-48 days after vaccine dose 2. Surrogate virus neutralization test (sVNT) and spike binding antibody titres were a median of 4.2 and 2.2 times lower, respectively, for AdV compared to mRNA vaccinees (p<0.001). Median percentages of memory B cells that recognized fluorescent-tagged spike and RBD were 2.9 and 8.3 times lower, respectively for AdV compared to mRNA vaccinees. Titres of IgG reactive with human Adenovirus type 5 hexon protein rose a median of 2.2-fold after AdV vaccination but were not correlated with anti-spike antibody titres. Together the results show that mRNA induced substantially more sVNT antibody than AdV vaccine due to greater B cell expansion and targeting of the RBD. Pre-existing AdV vector cross-reactive antibodies were boosted following AdV vaccination but had no detectable effect on immunogenicity. Key pointsO_LImRNA SARS-CoV-2 vaccine induced higher surrogate neutralizing antibody titres than adenoviral vaccine C_LIO_LImRNA vaccine induced a more potent, RBD-targeted B cell response than AdV vaccine C_LIO_LIAdenoviral vaccine boosted antibodies against human Adenovirus, but titres dont correlate with anti-spike titres C_LI
Subject(s)
COVID-19ABSTRACT
ObjectivesTo determine recommendations for the use of personal protective equipment (PPE) based on transmission risk for paediatric procedures in the Emergency Department during the COVID-19 pandemic. MethodsTwo survey rounds were conducted in April-May 2020. The survey presented a number of emergency medicine procedures relevant to the care of children, and asked respondents to provide PPE recommendations according to levels of community transmission, and whether or not the child had symptoms of acute respiratory illness. ResultsParticipants were recruited by approaching relevant professional groups, with 15 from the PREDICT network and 12 from the Australasian Society of Infectious Diseases (ASID) Paediatric Infectious Diseases (ANZPID) Group. Airborne PPE is recommended for resuscitative procedures and various respiratory procedures in most situations There were differences in opinion between emergency and paediatric infectious disease specialists with regards to most appropriate PPE for children without symptoms of COVID-19 in a setting of low community transmission, and for procedures involving the head, neck or airway. In general, emergency physicians were more likely to favour airborne PPE than infectious disease specialists. In the setting of high community transmission, there was a stronger tendency to recommend at least droplet precautions for most procedures – regardless of whether or not the child had symptoms. ConclusionsDifferences in PPE recommendations for various paediatric procedures between infectious disease specialists and emergency physicians were identified. Further research is urgently needed to clarify and quantify risks for many common interventions and determine strategies for multidisciplinary consensus regarding future recommendations.
Subject(s)
COVID-19 , Severe Acute Respiratory Syndrome , Communicable DiseasesABSTRACT
Encephalitis is most often caused by a variety of infectious agents, the identity of which is commonly determined through diagnostic tests utilising cerebrospinal fluid (CSF). Immune-mediated disorders are also a differential in encephalitis cases. We investigated the clinical characteristics and potential aetiological agents of unexplained encephalitis through metagenomic next-generation sequencing of residual clinical samples of multiple tissue types and independent clinical review. A total of 43 specimens, from both sterile and non-sterile sites, were collected from 18 encephalitis cases with no cause identified by the Australian Childhood Encephalitis study. Samples were subjected to total RNA sequencing to determine the presence and abundance of potential pathogens, to reveal mixed infections, pathogen genotypes, and epidemiological origins, and to describe the possible aetiologies of unexplained encephalitis. From this, we identified five RNA and two DNA viruses associated with human infection from both non-sterile (nasopharyngeal aspirates, nose/throat swabs, urine, stool rectal swab) and sterile (cerebrospinal fluid, blood) sites. These comprised two human rhinoviruses, two human seasonal coronaviruses, two polyomaviruses and one picobirnavirus. With the exception of picobirnavirus all have been previously associated with respiratory disease. Human rhinovirus and seasonal coronaviruses may be responsible for five of the encephalitis cases reported here. Immune-mediated encephalitis was considered clinically likely in six cases and RNA sequencing did not identify a possible pathogen in these cases. The aetiology remained unknown in nine cases. Our study emphasises the importance of respiratory viruses in the aetiology of unexplained child encephalitis and suggests that the routine inclusion of non-CNS sampling in encephalitis clinical guidelines/protocols could improve the diagnostic yield. Author Summary Encephalitis is caused by both infectious agents and auto-immune disorders. However, the aetiological agents, including viruses, remain unknown in around half the cases of encephalitis in many cohorts. Importantly, diagnostic tests are usually based on the analysis of cerebrospinal fluid which may limit their utility. We used a combination of meta-transcriptomic sequencing and independent clinical review to identify the potential causative pathogens in cases of unexplained childhood encephalitis. Accordingly, we identified seven viruses associated with both sterile and non-sterile sampling sites. Human rhinovirus and seasonal coronaviruses were considered as most likely responsible for five of the 18 encephalitis cases studied, while immune-mediated encephalitis was considered the cause in six cases, and we were unable to determine the aetiology in nine cases. Overall, we demonstrate the role of respiratory viruses as a cause of unexplained encephalitis and that sampling sites other than cerebrospinal fluid is of diagnostic value.