Update: Influenza Activity - United States and Worldwide, May 20-October 13, 2018

A Randomized Trial of Behavioral Nudges Delivered Through Text Messages to Increase Influenza Vaccination Among Patients With an Upcoming Primary Care Visit

PURPOSE

To evaluate if nudges delivered by text message prior to an upcoming primary care visit can increase influenza vaccination rates.

DESIGN

Randomized, controlled trial.

SETTING

Two health systems in the Northeastern US between September 2020 and March 2021.

SUBJECTS

74,811 adults.

INTERVENTIONS

Patients in the 19 intervention arms received 1-2 text messages in the 3 days preceding their appointment that varied in their format, interactivity, and content.

MEASURES

Influenza vaccination.

ANALYSIS

Intention-to-treat.

RESULTS

Participants had a mean (SD) age of 50.7 (16.2) years; 55.8% (41,771) were female, 70.6% (52,826) were White, and 19.0% (14,222) were Black. Among the interventions, 5 of 19 (26.3%) had a significantly greater vaccination rate than control. On average, the 19 interventions increased vaccination relative to control by 1.8 percentage points or 6.1% (P = .005). The top performing text message described the vaccine to the patient as "reserved for you" and led to a 3.1 percentage point increase (95% CI, 1.3 to 4.9; P < .001) in vaccination relative to control. Three of the top five performing messages described the vaccine as "reserved for you." None of the interventions performed worse than control.

CONCLUSIONS

Text messages encouraging vaccination and delivered prior to an upcoming appointment significantly increased influenza vaccination rates and could be a scalable approach to increase vaccination more broadly.

Text Message Reminders for the Second Dose of Influenza Vaccine for Children: An RCT

BACKGROUND AND OBJECTIVES

Among children requiring 2 influenza doses in a given season, second dose receipt nearly halves the odds of influenza. Nationally, many children do not receive both needed doses. This study sought to compare the effectiveness of text message reminders with embedded interactive educational information versus usual care on receipt and timeliness of the second dose of influenza vaccine.

METHODS

This trial took place over the 2017 to 2018 and 2018 to 2019 influenza seasons among 50 pediatric primary care offices across 24 states primarily from the American Academy of Pediatrics' Pediatric Research in Office Settings practice-based research network. Caregiver-child dyads of children 6 months to 8 years in need of a second influenza vaccination that season were individually randomized 1:1 into intervention versus usual care, stratified by age and language within each practice. Intervention caregivers received automated, personalized text messages, including educational information. Second dose receipt by April 30 (season end) and by day 42 (2 weeks after second dose due date) were assessed using Mantel Haenszel methods by practice and language. Analyses were intention to treat.

RESULTS

Among 2086 dyads enrolled, most children were 6 to 23 months and half publicly insured. Intervention children were more likely to receive a second dose by season end (83.8% versus 80.9%; adjusted risk difference (ARD) 3.8%; 95% confidence interval [0.1 to 7.5]) and day 42 (62.4% versus 55.7%; ARD 8.3% [3.6 to 13.0]).

CONCLUSIONS

In this large-scale trial of primary care pediatric practices across the United States, text message reminders were effective in promoting increased and timelier second dose influenza vaccine receipt.

Month of Influenza Virus Vaccination Influences Antibody Responses in Children and Adults

The improvement of influenza virus vaccines and the development of a universal product have been long-standing goals in pre-clinical and clinical research. To meet these goals and to understand the strengths and weaknesses of current vaccine strategies, scientists routinely study human responses toward seasonal influenza vaccines. This research is frequently performed with clinical samples taken throughout an influenza season, often without strict attention to the month of inoculation for each study participant. Here, we ask how the timing of vaccination affects outcomes. Results demonstrate significant influences of inoculation month on the immune response. During the progression from fall to winter months, there are changes in host lifestyles and in the frequencies of clinical/sub-clinical viral infections that can significantly alter vaccine immunogenicity. We now recommend routine assessment of inoculation month during clinical studies to inform data interpretation and expedite the development of successful vaccines. This recommendation is pertinent to numerous vaccine development efforts within and outside the influenza virus field.

Chimeric Hemagglutinin-Based Live-Attenuated Vaccines Confer Durable Protective Immunity against Influenza A Viruses in a Preclinical Ferret Model

Epidemic or pandemic influenza can annually cause significant morbidity and mortality in humans. We developed novel chimeric hemagglutinin (cHA)-based universal influenza virus vaccines, which contain a conserved HA stalk domain from a 2009 pandemic H1N1 (pH1N1) strain combined with globular head domains from avian influenza A viruses. Our previous reports demonstrated that prime-boost sequential immunizations induced robust antibody responses directed toward the conserved HA stalk domain in ferrets. Herein, we further followed vaccinated animals for one year to compare the efficacy and durability of these vaccines in the preclinical ferret model of influenza. Although all cHA-based immunization regimens induced durable HA stalk-specific and heterosubtypic antibody responses in ferrets, sequential immunization with live-attenuated influenza virus vaccines (LAIV-LAIV) conferred the best protection against upper respiratory tract infection by a pH1N1 influenza A virus. The findings from this study suggest that our sequential immunization strategy for a cHA-based universal influenza virus vaccine provides durable protective humoral and cellular immunity against influenza virus infection.

Detection and discrimination of influenza B Victoria lineage deletion variant viruses by real-time RT-PCR

Background

During the 2016/17 influenza season, influenza B/VIC lineage variant viruses emerged with two (K₁₆₂N₁₆₃) or three (K₁₆₂N₁₆₃D₁₆₄) amino acid (aa) deletions in the haemagglutinin (HA) protein. There are currently five antigenically distinct HA proteins expressed by co-circulating influenza B viruses: B/YAM, B/VIC V1A (no deletion), B/VIC V1A-2DEL (2 aa deletion) and two antigenically distinguishable groups of B/VIC V1A-3DEL (3 aa deletion). The prevalence of these viruses differs across geographical regions, making it critical to have a sensitive, rapid diagnostic assay that detects and distinguishes these influenza B variant viruses during surveillance.

Aim

Our objective was to develop a real-time RT-PCR (rRT-PCR) assay for detection and discrimination of influenza B/VIC lineage variant viruses.

Methods

We designed a diagnostic assay with one pair of conserved primers and three probes specific to each genetic group. We used propagated influenza B/VIC variant viruses and clinical specimens to assess assay performance.

Results

This rRT-PCR assay detects and distinguishes the influenza B/VIC V1A, B/VIC V1A-2DEL, and B/VIC V1A-3DEL variant viruses, with no cross-reactivity. This assay can be run as a multiplex reaction, allowing for increased testing efficiency and reduced cost.

Conclusion

Coupling this assay with the Centers for Disease Control and Prevention’s Human Influenza Virus Real-Time RT-PCR Diagnostic Panel Influenza B Lineage Genotyping Kit results in rapid detection and characterisation of circulating influenza B viruses. Detailed surveillance information on these distinct influenza B variant viruses will provide insight into their prevalence and geographical distribution and could aid in vaccine recommendations.

A Heterogeneous Swine Show Circuit Drives Zoonotic Transmission of Influenza A Viruses in the United States

Influenza pandemics are associated with severe morbidity, mortality, and social and economic disruption. Every summer in the United States, youths attending agricultural fairs are exposed to genetically diverse influenza A viruses (IAVs) circulating in exhibition swine, resulting in over 450 lab-confirmed zoonotic infections since 2010. Exhibition swine represent a small, defined population (∼1.5% of the U.S. herd), presenting a realistic opportunity to mitigate a pandemic threat by reducing IAV transmission in the animals themselves. Through intensive surveillance and genetic sequencing of IAVs in exhibition swine in six U.S. states in 2018 (n = 212), we characterized how a heterogeneous circuit of swine shows, comprising fairs with different sizes and geographic coverage, facilitates IAV transmission among exhibition swine and into humans. Specifically, we identified the role of an early-season national show in the propagation and spatial dissemination of a specific virus (H1δ-2) that becomes dominant among exhibition swine and is associated with the majority of zoonotic infections in 2018. These findings suggest that a highly targeted mitigation strategy, such as postponing swine shows for 1 to 2 weeks following the early-season national show, could potentially reduce IAV transmission in exhibition swine and spillover into humans, and this merits further study.IMPORTANCE The varying influenza A virus (IAV) exposure and infection status of individual swine facilitates introduction, transmission, and dissemination of diverse IAVs. Since agricultural fairs bring people into intimate contact with swine, they provide a unique interface for zoonotic transmission of IAV. Understanding the dynamics of IAV transmission through exhibition swine is critical to mitigating the high incidence of variant IAV cases reported in association with agricultural fairs. We used genomic sequences from our exhibition swine surveillance to characterize the hemagglutinin and full genotypic diversity of IAV at early-season shows and the subsequent dissemination through later-season agricultural fairs. We were able to identify a critical time point with important implications for downstream IAV and zoonotic transmission. With improved understanding of evolutionary origins of zoonotic IAV, we can inform public health mitigation strategies to ultimately reduce zoonotic IAV transmission and risk of pandemic IAV emergence.

Novel reassortant of H1N1 swine influenza virus detected in pig population in Russia

Pigs play an important role in interspecies transmission of the influenza virus, particularly as "mixing vessels" for reassortment. Two influenza A/H1N1 virus strains, A/swine/Siberia/1sw/2016 and A/swine/Siberia/4sw/2017, were isolated during a surveillance of pigs from private farms in Russia from 2016 to 2017. There was a 10% identity difference between the HA and NA nucleotide sequences of isolated strains and the most phylogenetically related sequences (human influenza viruses of 1980s). Simultaneously, genome segments encoding internal proteins were found to be phylogenetically related to the A/H1N1pdm09 influenza virus. In addition, two amino acids (129-130) were deleted in the HA of A/swine/Siberia/4sw/2017 compared to that of A/swine/Siberia/1sw/2016 HA.

Vaccination in the Elderly and IBD

PURPOSE OF REVIEW

Significant gaps in knowledge and utilization of vaccinations exist among practitioners providing care for patients with IBD. This review is intended to update the reader on best practices for vaccination within the IBD population with a specific focus on the elderly.

RECENT FINDINGS

Advances in IBD therapeutics have recently increased the number of immunosuppressive therapies available to practitioners. Differences in mechanisms of action of these medications have led to differential implications pertaining to vaccination strategies. Additionally, new vaccines, including the recombinant zoster vaccine, have recently become available for the use in the IBD population. Given the prominent role the IBD provider plays in the management of patients with IBD, a clear understanding of best practices is essential. This review provides a framework for the integration of optimal vaccination strategies for practitioners caring for adult and elderly patients with IBD.

Decreasing influenza vaccine coverage among adults with high-risk chronic diseases in Spain from 2014 to 2017

The objectives of this study were to estimate coverage of influenza vaccination in Spain among adults suffering chronic conditions, to assess time trends from 2014 to 2017 and to identify vaccine uptake predictors. We used individualized data of persons ≥15 y interviewed in the 2017 Spanish National Health Survey. Vaccine uptake and the presence of the chronic conditions analyzed (diabetes; cancer; chronic respiratory disease; chronic heart disease and cerebrovascular disease) were self-reported. Independent variables included sex, age and nationality. In 2017 overall influenza vaccination uptake among subjects with high-risk chronic conditions remained low (40.3%) and decreased significantly from 2014 (41.7%, adjusted OR 0.98 95%CI 0.84-0.98). The highest coverage was found among those with cerebrovascular disease (52.2%), diabetes (51.5%) and heart disease (51.4%) and the lowest figures for those suffering cancer (34.9%) and respiratory disease (35.1%). Coverage for cancer patients declined a 25% from 2014 to 2017. Older persons had higher coverages whereas females and immigrant population had lower uptakes.We conclude that influenza vaccination coverage among the high-risk population in Spain for suffering chronic conditions remains at a low level and has decreased significantly from 2014 to 2017, this affects more intensely to females and immigrants.

Molecular epidemiology and genetic characterization of influenza B virus in Lebanon during 2016-2018

BACKGROUND

Influenza B viruses are a major cause of serious acute respiratory infections in humans.

METHODS

Nasopharyngeal swabs were collected from subjects with influenza-like illness during October 2016-June 2018 and screened for influenza A and B. The hemagglutinin (HA) and neuraminidase (NA) genes of the Lebanese influenza B specimens were sequenced and phylogenetically compared with the vaccine strains and specimens from the Eastern Mediterranean Region and Europe.

RESULTS

Influenza A and B viruses co-circulated between October and May and peaked between January and March. During the 2016-2017 season, A/H3N2 (33.4%) and B/Yamagata (29.7%) were the predominantly circulating viruses followed by B/Victoria and A/H1N1pdm09 viruses. During the 2017-2018 season, A/H3N2 (31.5%) and A/H1Npdm09 (29.3%) were most prevalent with co-circulation of B/Yamagata and to a lesser extent B/Victoria viruses. The B/Yamagata specimens belonged to clade-3 while the B/Victoria belonged to clade-1A. None of the analyzed specimens had a mutation known to confer resistance to NA inhibitors (NAIs).

CONCLUSION

Multiple subtypes of influenza co-circulate each year in Lebanon with a peak between January and March. The trivalent vaccine included a B/Victoria strain which mismatched the B/Yamagata lineage that predominated during the study period, highlighting the importance of quadrivalent vaccines.