The safety and immunogenicity of FluMos-v1, an experimental nanoparticle influenza vaccine developed to provide long-lasting protection against multiple flu virus strains, is being evaluated in a first-in-human, Phase 1 trial. 

Scientists from NIH’s National Institute of Allergy and Infectious Diseases (NIAID) developed FluMos-v1 to stimulate antibodies against multiple influenza virus strains by displaying part of the influenza virus hemagglutinin (HA) protein on self-assembling nanoparticle scaffolds. 

Similarities with available flu vaccines: FluMos-v1 vaccine is designed to elicit antibodies directed against the hemagglutinin protein from four different virus strains, two influenza type A strains of H1 and H3 subtype and two influenza type B strains.

Dissimilarities with available flu vaccines: FluMos-v1 displays multiple copies of each of the four HA types. The 20 HA epitopes arrayed in repeating patterns on the nanoparticle scaffolds sent a strong signal to the immune system and prompted a robust antibody response in animal models. 

The trial will include 35 healthy volunteers, aged 15-50 years. Of these, 15 trial participants will be given an FDA approved quadrivalent seasonal flu vaccine (Single IM dose), while 5 would be administered the experimental vaccine (single dose 20mcg). If there are no safety concerns with this dose then an additional 15 volunteers would be given one 60 mcg dose of the investigational vaccine.

All study participants will be required to monitor their body temperature and record any adverse effects such as redness, pain or swelling at the injection site, tiredness, headache, muscle aches or joint pain. Blood samples would be collected periodically for 40 weeks to determine levels of hemagglutinin-directed antibodies produced following vaccination. Oral mucosal samples would also be taken for research purposes to evaluate the oral mucosal immune response to the vaccine. 

In animal studies, FluMos-v1 was shown to generate antibodies to hemagglutinin included in the vaccine, equal to or slightly more than the commercially available vaccines. But these studies also revealed that it was superior to commercial vaccines in eliciting antibodies to two influenza type A subtypes (H5 and H7) not included in the vaccine.  

“Flu viruses are constantly changing, so the vaccine composition is reviewed each year and updated as needed based on which influenza viruses are making people sick, the extent to which those viruses are spreading, and how well the previous season’s vaccine protects against those viruses” (CDC).

It is therefore hoped that a universal flu vaccine would obviate the need for annual flu vaccination.

(Source: NIH press release, June 1, 2021)

Dr Sanjay Kalra, DM, Bharti Hospital, KarnalImmediate Past President, Endocrine Society of India