Burden of disease of respiratory syncytial virus in older adults and adults considered at high risk of severe infection.

Background: Availability of new vaccines for adults has increased interest in understanding Canada's respiratory syncytial virus (RSV) burden in older adults and adults considered at high risk of severe infection.

Objective: To characterize the burden of RSV disease in Canada by joint analysis of the published literature and hospitalization data from a healthcare administrative database.

Methods: Electronic databases of published literature were searched to identify studies and systematic reviews reporting data on outpatient visits, hospitalizations, intensive care unit (ICU) admissions and deaths associated with RSV infection in adults.

Summary of the National Advisory Committee on Immunization (NACI) Supplemental Guidance on Influenza Vaccination in Adults 65 Years of Age and Older.

Background: Adults 65 years of age and older are at higher risk of influenza complications, such as hospitalization and death. As a result, seasonal influenza immunization is particularly important for this group.

Objective: This supplemental statement provides an evidence summary on the preferential use of one or more of the age-appropriate influenza vaccines for adults 65 years of age and older, over other age-appropriate influenza vaccines.

Trivalent and quadrivalent seasonal influenza vaccine in adults aged 60 and older: a systematic review and network meta-analysis.

Objectives: To compare the efficacy of influenza vaccines of any valency for adults 60 years and older.

Design And Setting: Systematic review with network meta-analysis (NMA) of randomised controlled trials (RCTs). MEDLINE, EMBASE, JBI Evidence-Based Practice (EBP) Database, PsycINFO, and Cochrane Evidence -Based Medicine database were searched from inception to 20 June 20, 2022.

Burden of disease of respiratory syncytial virus in infants, young children and pregnant women and people.

Background: Passive immunization products for infants and pregnant women and people have sparked interest in understanding Canada's respiratory syncytial virus (RSV) burden. This rapid review examines RSV burden of disease in infants, young children and pregnant women and people.

Methods: Electronic databases were searched to identify studies and systematic reviews reporting data on outpatient visits, hospitalizations, intensive care unit admissions, deaths and preterm labour associated with RSV.

Summary of the National Advisory Committee on Immunization (NACI) Statement-Recommendations on Fractional Influenza Vaccine Dosing in the Event of a Shortage: Pandemic preparedness.

Background: At the commencement of a pandemic, it is important to consider the impact of respiratory infections on the health system and the possibility of vaccine shortages due to increased demand. In the event of an influenza vaccine shortage, a strategy for administration of fractional influenza vaccine doses might be considered. This article reviews the available evidence for efficacy, effectiveness, immunogenicity and safety of fractional influenza vaccine dosing, and summarizes the National Advisory Committee on Immunization (NACI) recommendations on fractional dosing strategies by public health programs in Canada.

Intraseasonal waning immunity of seasonal influenza vaccine - A systematic review and meta-analysis.

Background: Recently, studies have suggested that influenza antibody titers decline with time since vaccination. Duration of vaccine protection is an important factor to determine the optimal timing of vaccination.

Objective: We aimed to systematically evaluate the implication of waning immunity on the duration of seasonal influenza vaccine antibody response.

Evaluation of influenza case definitions for use in real-world evidence research.

Background: Laboratory confirmation of influenza is not routinely done in practice. With the advent of big data, it is tempting to use healthcare administrative databases for influenza vaccine effectiveness studies, which often rely on clinical diagnosis codes. The objective of this article is to compare influenza incidence curves using international case definitions derived from clinical diagnostic codes with influenza surveillance data from the United States (US) Centers for Disease Control and Prevention (CDC).

Evaluation of the 2018-2019 vaccine effectiveness against medically attended influenza-like illness using medical records and claims data.

Background: Healthcare administrative databases are a rich source of information that could be leveraged to estimate real-world influenza vaccine effectiveness (VE). We aimed to evaluate the VE of standard egg-based influenza vaccines and determine if administrative healthcare data provide accurate VE estimates compared to the US CDC data.

Methods: This retrospective cohort study was conducted during the 2018-2019 influenza season.

Effect of early measles vaccination on long-term protection: A systematic review.

Background: In North America, the first dose of a measles-containing vaccine (MCV1) is administered at ≥12 months of age. However, MCV1 may be given to infants <12 months living in highly endemic areas or traveling to these areas. Although an early dose of MCV1 leads to immediate protection, it remains unclear how this impacts long-term immunity.

Is there a difference in the immune response, efficacy, effectiveness and safety of seasonal influenza vaccine in males and females? - A systematic review.

Introduction: Seasonal influenza is an important cause of morbidity and mortality, despite being vaccine-preventable. Sex factors (genes and hormones) seem to impact individuals' susceptibility to infectious diseases and their response to vaccination. However, most vaccine studies do not explicitly assess sex differences in vaccine response, but rather adjust for sex.

Multiplex Polymerase Chain Reaction Panel for Suspected Pertussis: What About a Positive Mycoplasma pneumoniae Result?

Background: The use of bacterial multiplex polymerase chain reaction (PCR) in children with suspected pertussis sometimes yields unexpected positive results for Mycoplasma pneumoniae. We aimed to evaluate the clinical significance of positive M. pneumoniae results in this population.

Impact of influenza vaccination on healthcare utilization - A systematic review.

Introduction: Although a vaccine-preventable disease, influenza causes approximately 3-5 million cases of severe illness and about 290,000-650,000 deaths worldwide, which occur primarily among people 65 years and older. Nonetheless, prevention of influenza and its complications rely mainly on vaccination. We aimed to systematically evaluate influenza vaccine effectiveness at reducing healthcare utilization in older adults, defined as the reduction of outpatient visits, ILI and influenza hospitalizations, utilization of antibiotics and cardiovascular events by vaccination status during the influenza season.