Researchers have made significant strides in developing an oral norovirus vaccine, with promising results showing that it is safe and effective in older adults. The VXA-G1.1-NN vaccine tablet was tested on 65 participants aged 55 to 80 years and showed robust systemic and mucosal immune responses.
Norovirus infections cause approximately 20 million cases of acute gastroenteritis annually, resulting in 70,000 hospitalizations and up to 800 deaths. Older adults are disproportionately affected, with 90% of norovirus-associated deaths occurring in individuals aged 65 and older.
The study, published in Science Translational Medicine, found that vaccination with VXA-G1.1-NN was well tolerated across all dose levels, with mild to moderate symptoms reported as the most common side effects. The vaccine induced strong immune responses, including increases in serum antibodies and mucosal immunity.
Notably, the vaccine’s effectiveness was comparable to younger adults from a prior clinical trial, suggesting that it may be suitable for older adults. Oral administration of VXA-G1.1-NN was found to be safe and capable of generating durable immune responses.
Further trials are required to evaluate the vaccine’s effectiveness, but the study supports the feasibility of an oral vaccine for norovirus. A phase 2 clinical trial is currently investigating a bivalent version targeting both GI.1 and GII.4 norovirus genogroups to explore potential cross-protection against diverse norovirus strains.
Overall, this breakthrough could offer advantages over injectable vaccines, including ease of distribution and self-administration. The development of an oral norovirus vaccine has the potential to significantly reduce the burden of norovirus infections on older adults and healthcare systems.
Source: https://medicalxpress.com/news/2025-03-oral-norovirus-vaccine-safety-strong.html