Vaxart and Novavax reported data from their respective norovirus and COVID-19/flu combination vaccines on Wednesday. The early-stage results for Vaxart's programme pushed its stock up 28%, while Novavax's candidate will likely face higher scrutiny given US health regulators' increased standards for COVID-19 jabs (see – Physician Views Results: Doctors divided on ethics, impact of new COVID-19 policy).Last month, the FDA announced that it would require "new vaccines" to be tested in placebo-controlled trials. A regulatory framework for COVID-19 vaccines specifically detailed how booster shots could be approved for older adults and younger, at-risk individuals on the basis of immunogenicity data, but that placebo-controlled trials would be required to clear updated jabs for healthy people between the ages of five months and 65 years old. A day after the framework was released, Moderna voluntarily withdrew its marketing for mRNA-1083, a combination COVID-19/flu vaccine, after the FDA said that Phase III flu efficacy data would be required for approval (see – ViewPoints: A vaccine expert's grim verdict on Kennedy's health agenda). Pill protectionVaxart, which develops oral recombinant pill vaccines, shared Phase I data suggesting that its second-generation norovirus constructs designed to protect against the GI.1 and GII.4 genotypes can elicit a better immune response than its initial versions. The company randomised 60 patients evenly across three cohorts to receive either its first-generation products, an equivalent dose of its updated vaccine constructs, or a low-dose of the next-gen pills. Topline data showed that patients who received the standard dose had a 141% increase in GI.1 norovirus blocking antibody assay (NBAA) titres compared with the first-generation version, and a 94% increase for GII.4 NBAA titres. "Consistent with what we previously demonstrated in animal models, these clinical data prove that our second-generation constructs increased antibody titres in humans, providing additional compelling evidence of the potential of our oral pill vaccine candidates," said Sean Tucker, Vaxart’s founder and chief scientist. "The significant increases in NBAA titers reported today give us high confidence that our second-generation constructs will provide even greater protection against infection."Vaxart plans to move its norovirus vaccine pills into Phase IIb testing next half, but advancing the programme is dependent on if it can secure funding or a partner. If the company does find the means to continue work on the constructs, it said a Phase III study could launch next year. Setting up for registrational studyNovavax said that its COVID-19-Influenza Combination (CIC) vaccine induced similar immune responses as two separate jabs in a descriptive Phase III study of 2,000 adults aged 65 and older.The trial compared the CIC programme — as well as an experimental, standalone trivalent hemagglutinin nanoparticle seasonal influenza (tNIV) jab designed to protect against the H1N1, H3N2 and B flu strains — against Novavax's own COVID-19 vaccine Nuvaxovid and Sanofi's Fluzone HD. According to the company, both investigational programmes elicited "robust" immune responses to their respective viral strains, reaching a 2.4 to 5.7-fold increase compared with baseline. The study was not powered to demonstrate statistical significance, but rather to inform the design of a registrational Phase III trial. In regards to safety, both the CIC and tNIV candidates were well tolerated and had reactogenicity similar to the two comparators, with nearly all adverse events being mild or moderate.