Flu News Friday 8/6/21
Read the latest on influenza vaccines in this week’s roundup.
Image credit: CDC Public Health Image Library
Here, a laboratory technician was performing hemagglutination inhibition (HI) testing, in China, during the country’s 2014-2015 flu season. Scientists use the HI assay to antigenically characterize circulating seasonal influenza viruses.
The Latest in Influenza Vaccines
Conference Announcement: The Eighth ESWI Influenza Conference is December 4th to 7th, 2021. Join colleagues and peers from around the world in Salzburg for the largest conference dedicated to influenza, RSV disease and Covid-19. Register here. Abstracts are due September 3, 2021; submit abstracts here.
1. Intradermal vaccination of live attenuated influenza vaccine protects mice against homologous and heterologous influenza challenges.
Lee et al., npj Vaccines / August 4, 2021
Scientists designed an injected, live attenuated influenza vaccine (LAIV) in which the non-structural 1 (NS1) protein was deleted to limit (attenuate) vaccine pathogenicity. The vaccine demonstrated immunogenicity and was found to exhibit durable protection against lethal challenge with homologous and heterologous strains; the results suggested full protective immunity for at least six months.
2. Seasonal influenza vaccination policies in the 194 WHO Member States: The evolution of global influenza pandemic preparedness and the challenge of sustaining equitable vaccine access
Morales et al., Vaccine / August 2021
Researchers examined changes to national seasonal influenza vaccination policies reported on the WHO/UNICEF Joint Reporting Forms on Immunization (JRF) in 2014 and 2018 for the 194 World Health Organization Member States. An understanding of the global landscape of policies provides a baseline for efforts to build upon existing programs in the context of pandemic preparedness, while identifying barriers, particularly in low-and middle-income countries (LMICs), to initiate and sustain these policies.
3. Cellular responses at the application site of a high-density microarray patch delivering an influenza vaccine in a randomized, controlled phase I clinical trial
Depelsenaire et al., PLOS One / July 30, 2021
A microarray patch (MAP) influenza vaccine was tested in a phase I clinical trial. While traditional influenza vaccines utilize intranasal or injected routes of administration, transdermal patch vaccines are an attractive alternative for their ability to be more practical in lower-resource settings, safer, culturally acceptable, and dose-sparing. The split, monovalent patch vaccine was found to exhibit immunogenicity and the data indicated an adaptive T cell response.
4. Single Replication M2SR Influenza Vaccine Induced Immune Responses Associated with Protection Against Human Challenge with Highly Drifted H3N2 Influenza Strain
Eiden et al., The Journal of Infectious Diseases /
July 29, 2021
Currently licensed vaccines targeting the H3N2 Influenza A subtype exhibit lower vaccine effectiveness than for vaccines targeting the H1N1 subtype or Influenza B viruses. Therefore, designing vaccines with broader protection are needed. In a phase II study, a supraseasonal influenza vaccine protected trial participants with vaccine-induced neutralizing antibodies when challenged with a “highly antigenically drifted” H3N2 strain. The vaccine induced both mucosal and systemic immunity. A “wild-type like” M2-deficient single replication influenza virus (M2SR) expressing hemagglutinin (HA) and neuraminidase (NA) from the H3N2 subtype (clade 1) was used for the vaccine, whereas the H3N2 subtype (clade 3) was used for the challenge strain.
5. Assay Harmonization and Use of Biological Standards To Improve the Reproducibility of the Hemagglutination Inhibition Assay: a FLUCOP Collaborative Study
Waldock et al., mSphere / July 28, 2021
The hemagglutinin inhibition (HI) assay is the traditional assay used to evaluate influenza correlates of immune protection. Because procedures and reagents are often different among labs, there is inter-lab variability in the test results. Scientists compared the various protocols from members of the FLUCOP consortium and studied the impact of HI assay harmonization and the use of biological standards to reduce this variability and increase reproducibility.
6. Links between fecal microbiota and the response to vaccination against influenza A virus in pigs
Borey et al., npj Vaccines / July 22, 2021
Scientists examined the evolution of B-cell immune responses upon influenza A virus (IAV) vaccination in pigs, and if the intensity of immune response was correlated with a shift in the fecal microbiota composition. It was found that particular types of bacteria were correlated and predictive of an “extreme,” IAV-specific IgG antibody response. Studying these host-pathogen interactions in animal models could shed light on why there is variability of vaccine immune responses within a single population, in animals or humans.
7. Canonical features of human antibodies recognizing the influenza hemagglutinin trimer interface
Zost et al., The Journal of Clinical Investigation /
June 22, 2021
Broadly reactive antibodies for head domain of the Influenza A virus’s hemagglutinin (HA) are considered to be rare. Scientists studied genetic and structural features common among broadly protective antibodies that recognize a recently identified Achilles’ heel of the Influenza A virus, the head domain’s trimer interface (T)). The study suggests the TI is a conserved antigenic site, meaning that this site is recognized by a broad array of human antibodies, and is recommended to serve as a target for the design of future universal influenza vaccines.
8. A Blueprint for Preventing Another Pandemic
TIME Magazine / June 2021
TIME Magazine, with guidance from the University of Washington Alliance for Pandemic Preparedness surveyed 73 experts across the globe on what should be done to prevent and mitigate the next health threat. Experts scored pandemic prevention measures by feasibility and priority. The respondents came from sectors including public health, infectious disease, immunology, hospital administration, data and technology, environment and climate, health inequity, supply chains and biosecurity.