An American team studied the impact of muscle atrophy and corticosteroid therapy on the immune response to messenger RNA (mRNA) vaccines against SARS-CoV-2 in 14 people aged between 20 and 60 with neuromuscular diseases (MNM). Participants were mostly nonambulant (13/14) and had Duchenne or Becker muscular dystrophy (9/14), SMN1-related proximal spinal muscular atrophy (SMA) (1/14) or limb girdle muscular dystrophy (2/14).
The results of this study show that:
- IgG levels 14 days after the second injection of the vaccine are comparable in people with vaccinated MNM and in a control group without MNM also vaccinated;
- compared to an unvaccinated control group having contracted Covid-19 (Covid+), IgG levels are 11 times higher for vaccinated people (healthy or suffering from MNM but not treated with corticosteroids) and nine times for patients vaccinated and on corticosteroids;
- all vaccinated people perform better in the virus neutralization test (+52.9%) than Covid+ people;
- post-vaccination symptoms remain moderate and comparable between participants with and without MNM.
These results suggest a correct vaccine response and protection rate, in the short term, in patients affected by MNM.