#Safety and #immunogenicity of ascending doses of #influenza A(#H7N9) inactivated #vaccine with or without MF59®

#Immunogenicity of a #booster dose of a bivalent (Asp614Gly and #omicron BA.4/5 #variant) self-amplifying #mRNA #SARS-CoV-2 booster vaccine versus the BNT162b2 omicron BA.4/5 mRNA vaccine: a randomised phase 3 trial

Source: Lancet Infectious Diseases, SummaryBackgroundWe previously showed that ARCT-154, a self-amplifying mRNA COVID-19 vaccine, had improved immunogenicity and antibody persistence compared with …

#Safety, #immunogenicity, and optimal dosing of a MVA-based #vaccine against #MERS-CoV in healthy adults: a phase 1b, double-blind, randomised placebo-controlled clinical trial

Source: Lancet Infectious Diseases, SummaryBackgroundMERS-CoV is a respiratory pathogen with a case-fatality rate of 36%, and for which no vaccines are currently licensed. MVA-MERS-S is a candidate…

Preclinical #immunogenicity and #safety of #hemagglutinin-encoding #modRNA #influenza #vaccines

Source: npj Vaccines, AbstractSeasonal epidemics of influenza viruses are responsible for a significant global public health burden. Vaccination remains the most effective way to prevent infection;…

Immunogenicity and biodistribution of lipid nanoparticle formulated self-amplifying mRNA vaccines against H5 avian influenza - npj Vaccines

This study reports on the immunogenicity and biodistribution of H5 hemagglutinin (HA)-based self-amplifying (sa) mRNA vaccines in mice. Four sa-mRNA vaccines encoding either a secreted full-length HA, a secreted HA head domain, a secreted HA stalk domain, or a full-length membrane-anchored HA were investigated. All vaccines elicited an adaptive immune response. However, the full-length HA sa-RNA vaccines demonstrated superior performance compared to head and stalk domain vaccines. The antibody titers positively correlated with the vaccine dose. Cellular immune responses and antigen-specific IgA antibodies in the lungs were also observed. The comparison of the sa-mRNA vaccines encoding the secreted and membrane-anchored full-length HA revealed that anchoring of the HA to the membrane significantly enhanced the antibody and cellular responses. In addition to the injection site, the intramuscularly injected sa-mRNA-LNPs were also detected in the draining lymph nodes, spleen, and to a lesser extent, in the lung, kidney, liver, and heart.

A synthetic TLR4 agonist significantly increases humoral immune responses and the protective ability of an MDCK-cell-derived inactivated H7N9 vaccine in mice - Archives of Virology

Antigenically divergent H7N9 viruses pose a potential threat to public health, with the poor immunogenicity of candidate H7N9 vaccines demonstrated in clinical trials underscoring the urgent need for more-effective H7N9 vaccines. In the present study, mice were immunized with various doses of a suspended-MDCK-cell-derived inactivated H7N9 vaccine, which was based on a low-pathogenic H7N9 virus, to assess cross-reactive immunity and cross-protection against antigenically divergent H7N9 viruses. We found that the CRX-527 adjuvant, a synthetic TLR4 agonist, significantly enhanced the humoral immune responses of the suspended-MDCK-cell-derived H7N9 vaccine, with significant antigen-sparing and immune-enhancing effects, including robust virus-specific IgG, hemagglutination-inhibiting (HI), neuraminidase-inhibiting (NI), and virus-neutralizing (VN) antibody responses, which are crucial for protection against influenza virus infection. Moreover, the CRX-527-adjuvanted H7N9 vaccine also elicited cross-protective immunity and cross-protection against a highly pathogenic H7N9 virus with a single vaccination. Notably, NI and VN antibodies might play an important role in cross-protection against lethal influenza virus infections. This study showed that a synthetic TLR4 agonist adjuvant has a potent immunopotentiating effect, which might be considered worth further development as a means of increasing vaccine effectiveness.

A Phase 2 Clinical Trial to Evaluate the Safety, Reactogenicity, and Immunogenicity of Different Prime-Boost Vaccination Schedules of 2013 and 2017 A(H7N9) Inactivated Influenza Virus Vaccines Administered with and without AS03 Adjuvant in Healthy US Adults

AbstractIntroduction. A surge of human influenza A(H7N9) cases began in 2016 in China due to an antigenically distinct lineage. Data are needed about the s

Immunogenicity and safety of varying dosages of a fifth-wave influenza A/H7N9 inactivated vaccine given with and without AS03 adjuvant in healthy adults - PubMed

AS03 adjuvant improved the immune responses to an inactivated fifth-wave H7N9 influenza vaccine, particularly in younger adults, but invoked lower responses to drifted H7N9 strains. These findings may inform future influenza pandemic preparedness strategies.