Coronavirus disease-19 : an interim evidence Synthesis of the World Association for Infectious Diseases and Immunological Disorders (Waidid)

Coronavirus disease 2019 (COVID-19) is a rapidly evolving, highly transmissible, and potentially lethal pandemic caused by a novel coronavirus, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). As of June 11 2020, more than 7,000,000 COVID-19 cases have been reported worldwide, and more than 400,000 patients have died, affecting at least 188 countries. While literature on the disease is rapidly accumulating, an integrated, multinational perspective on clinical manifestations, immunological effects, diagnosis, prevention, and treatment of COVID-19 can be of global benefit. We aimed to synthesize the most relevant literature and experiences in different parts of the world through our global consortium of experts to provide a consensus-based document at this early stage of the pandemic

Global Perspectives on Immunization During Pregnancy and Priorities for Future Research and Development: An International Consensus Statement.

Immunization during pregnancy has been recommended in an increasing number of countries. The aim of this strategy is to protect pregnant women and infants from severe infectious disease, morbidity and mortality and is currently limited to tetanus, inactivated influenza, and pertussis-containing vaccines. There have been recent advancements in the development of vaccines designed primarily for use in pregnant women (respiratory syncytial virus and group B Streptococcus vaccines). Although there is increasing evidence to support vaccination in pregnancy, important gaps in knowledge still exist and need to be addressed by future studies. This collaborative consensus paper provides a review of the current literature on immunization during pregnancy and highlights the gaps in knowledge and a consensus of priorities for future research initiatives, in order to optimize protection for both the mother and the infant

Evaluation of pertussis immunization during pregnancy

Pertussis disease is most severe among young infants, leading to high morbidity and mortality. To reduce the burden of pertussis disease among young infants, immunization against pertussis during pregnancy has been implemented in an increasing number of countries over the past decade. My research goals have focused on addressing important knowledge gaps in the field of pertussis immunization during pregnancy to inform an evidence-based immunization program. Using data on hospitalized pertussis cases admitted to pediatric tertiary care centers in Canada, I report that the highest morbidity and mortality from pertussis is among infants <2 months of age with an incidence rate of 116.4/100,000/year, 38% intensive-care unit admission rate, and 2.3% case fatality rate. Age <16 weeks, encephalopathy and prematurity were independently associated with a 5-fold, 21-fold and 6-fold increased risk for intensive-care unit admission, respectively. I also developed a novel approach that enables comprehensive characterization of anti-pertussis immunoglobulin G (IgG) avidity using a range of bond-breaking agent concentrations combined with high-dimensional biology statistical tools. I applied this approach on cord blood samples, and found that vaccination against pertussis during pregnancy was associated with high levels of high-avidity antibodies. I also found that maternal pertussis vaccination at 28–32 weeks gestation was associated with higher cord blood anti-pertussis IgG avidity that vaccination at 33–36 weeks gestation. Furthermore, I compared antibody responses after primary and/or booster immunization in infants born to women with and without pertussis immunization during pregnancy. I found lower vaccine-induced antibody responses to pertussis, diphtheria and some Streptococcus pneumoniae serotypes in infants born to women vaccinated against pertussis during pregnancy compared with infants of unvaccinated women. The body of work presented here assists public health policy makers to reach evidence-based recommendations across countries. Supporting earlier immunization in the 3rd trimester will be of particular clinical relevance for preterm infants who would completely miss out on protection via maternal antibodies if immunization only occurred in late pregnancy. These data from the meta-analysis supports enhanced surveillance of pertussis, diphtheria and invasive pneumococcal disease in infants to determine the clinical significance of this effect.Medicine, Faculty ofExperimental Medicine, Division ofMedicine, Department ofGraduat

Meningococcal vaccination in pregnancy

Invasive meningococcal disease causes meningitis and septicemia worldwide with highest rates of disease occurring in children <2 years of age, and in particular young infants. Vaccination during pregnancy has been a successful strategy for prevention of other infections in young infants, most notably tetanus, pertussis and influenza. However, few studies of meningococcal vaccines in pregnancy have been undertaken, and none include the most commonly used current vaccines to prevent disease by capsular groups A, B, C, W and Y. The limited data suggest that the older polysaccharide vaccines are immunogenic, but the impact on prevention of infant disease has not been measured. Further studies of MenB protein vaccines and MenA protein-polysaccharide conjugate vaccines in particular are needed if vaccination in pregnancy is to be utilized as an approach to prevention of meningococcal disease in young infants

Challenges in evaluating SARS-CoV-2 vaccines during the pandemic

Key points: - Challenges to the evaluation of SARS-CoV-2 candidate vaccines prior to approval or licensure during the ongoing pandemic include rapidly changing levels of exposure to the virus and population immunity, social distancing practices, and the possibility of antibody-dependent enhancement of disease. - In order to measure vaccine efficacy accurately, researchers should account for these factors in sample size calculations and also carefully consider selection of trial endpoints. - SARS-CoV-2 vaccines must also be evaluated in populations known to be at increased risk for severe COVID-19, such as older adults, people of African descent, and people with multiple comorbidities. - Given the speed of SARS-CoV-2 vaccine development careful attention must be paid to post-licensure assessment of vaccines, including the risk of antibody dependent enhancement of disease, which must be actively monitored closely over multiple years after vaccination.Medicine, Faculty ofInfectious Diseases, Division ofPediatrics, Department ofReviewedFacultyPostdoctora

Pertussis immunization during pregnancy : a review of the evidence and gap analysis

Some countries have experienced marked increases in pertussis incidence, morbidity and mortality, especially among young infants. To protect infants too young to be vaccinated, several countries recommend tetanus-diphtheria-acellular pertussis (Tdap) immunization during pregnancy, preferably during late second or third trimester. Protection is postulated to result from transplacental transfer of enhanced maternal levels of pertussis-specific antibodies. Maternal immunization with Tdap vaccine has been shown to be highly effective in preventing pertussis disease in young infants, but instances of vaccine failure have been reported. Maternally derived antibodies also have the potential to blunt infants’ immune responses to primary pertussis immunization, but the clinical relevance of this is unclear. Maternal titers of pertussis antibodies decline rapidly following parturition so re-immunization is likely needed in subsequent pregnancies. While scientific evidence supporting maternal immunization against pertussis is accumulating, there are still important knowledge gaps that should be addressed by future research.Medicine, Faculty ofNon UBCPediatrics, Department ofReviewedFacultyResearche

The immune system of HIV-exposed uninfected infants

Infants born to human immunodeficiency virus (HIV) infected women are HIV-exposed but the majority remains uninfected [i.e. HIV-exposed uninfected (HEU)]. HEU infants suffer greater morbidity and mortality from infections compared to HIV-unexposed (HU) peers. The reason(s) for these worse outcomes are uncertain, but could be related to an altered immune system state. This review comprehensively summarizes the current literature investigating the adaptive and innate immune system of HEU infants. HEU infants have altered cell-mediated immunity, including impaired T-cell maturation with documented hypo- as well as hyper-responsiveness to T-cell activation. And although prevaccination vaccine-specific antibody levels are often lower in HEU than HU, most HEU infants mount adequate humoral immune response following primary vaccination with diphtheria toxoid, haemophilus influenzae type b, whole cell pertussis, measles, hepatitis B, tetanus toxoid, and pneumococcal conjugate vaccines. However, HEU infants are often found to have lower absolute neutrophil counts as compared to HU infants. On the other hand, an increase of innate immune cytokine production and expression of co-stimulatory markers has been noted in HEU infants, but this increase appears to be restricted to the first few weeks of life. The immune system of HEU children beyond infancy remains largely unexplored.SCOPUS: re.jinfo:eu-repo/semantics/publishe