Sanofi's protein-based non-mRNA COVID-19 vaccine Nuvaxovid (NVX-CoV2705) demonstrated statistically significant lower systemic reactogenicity (the expected side effects that might occur following vaccination) compared to mNEXSPIKE (mRNA-1283), Moderna's latest mRNA COVID-19 vaccine, across all pre-specified endpoints in the COMPARE study. The randomized, double-blind study, which enrolled 1,000 adults in the US, was presented at the European Society of Clinical Microbiology and Infectious Diseases (ESCMID) Global Congress in Munich, Germany. These results address a persistent challenge: despite the end of the pandemic, COVID-19 continues to cause significant hospitalizations and deaths globally, while placing considerable strain on health systems during seasonal peaks.
Yet vaccination uptake remains low, with concerns about vaccine side effects ranking among the top reasons cited by adults for not getting vaccinated against COVID-19. In the COMPARE study, when side effects did occur with Nuvaxovid, they were less severe and shorter in duration compared to mNEXSPIKE. Severe systemic symptoms (body-wide reactions such as fatigue, headache, or fever) that prevent people from carrying out their normal daily activities were more than 50% less frequent with Nuvaxovid, affecting fewer than one in ten Nuvaxovid recipients compared to one in five mNEXSPIKE recipients, an analysis of the data showed.
Severe local symptoms (reactions at the injection site such as pain, redness, or swelling) with Nuvaxovid were rare, and more than 75% less frequent compared to mNEXSPIKE. This was reflected in the study participants' own experience: those who received Nuvaxovid were nearly twice as likely as mNEXSPIKE recipients to say they would definitely choose the same vaccine type again the following year. The study met its primary endpoint ?
the probability of experiencing at least one systemic reaction within seven days of vaccination - with statistical significance, with 91.6% of mNEXSPIKE recipients affected compared to 83.6% of Nuvaxovid recipients (risk difference: 8.0%; 95% CI: 4.0%?12%; p Coronavirus disease (COVID-19) is an infectious disease caused by the SARS-CoV-2 virus. Most people infected with the virus will experience mild to moderate respiratory illness and recover without requiring special treatment. However, some will become seriously ill resulting in hospitalization and death.
The disease not only causes immediate health impacts but also increases the long-term risk of cardiovascular complications, including heart attacks and strokes, and older adults hospitalized for COVID-19 face substantially higher mortality risk than those hospitalized for influenza. Older adults and those with chronic conditions - including cardiovascular disease, chronic lung disease, diabetes, and obesity - face the highest risk of severe illness. In the US, an estimated 74% of adults have at least one such risk factor, underscoring the scale of the vulnerable population that stands to benefit from effective and well-tolerated COVID-19 vaccination.
