Research shows that the mRNA vaccines produce slightly stronger immunity, with more frequent CD8+ involvement and a more slowly fading antibody response, than Novavax[1], and Novavax has somewhat milder short-term side effects[2].
[1] "Summary of the evidence" section of https://www.nature.com/articles/s41541-025-01302-x
[2] https://www.cidrap.umn.edu/covid-19/novavax-says-its-covid-vaccine-produces-fewer-milder-reactions-pfizer-version
I know people who assert they received long-lasting injuries from mRNA vaccines, but have not heard this about Novavax.

Durable vaccine-induced immunity is the basis of long-term protection against infection and disease. This review covers three topics. First, we describe the immunological foundations of durable response and its determinants (e.g., vaccine design, host, and pathogen factors). Second, we summarize the current evidence regarding the durable immune responses conferred by mRNA- and adjuvanted protein-based vaccine platforms. Lastly, we discuss the challenges in developing durable mRNA vaccines and outline future considerations.

Preliminary data showed Novavax's non-mRNA JN.1 COVID-19 vaccine induced lower frequency and severity of short-term side effects and impact on daily life compared with Pfizer-BioNTech mRNA vaccine...