Final answer:
Epidemics of neuromuscular disease in the summer may be due to seasonal changes in the host's immune response, rather than the pathogen. Cells involved in antibody-mediated immunity are usually elevated in winter, while cell-mediated immunity is higher in the summer. This pattern has been observed in animal models and human studies.
Step-by-step explanation:
When epidemics of neuromuscular disease occur in the summer, it is suspected that the seasonal variation in infection and disease prevalence may be due to changes primarily in the host, not the pathogen. For example, immune cells such as helper T-lymphocytes and B-lymphocytes, which are important for antibody-mediated immunity, are usually elevated in winter, but cell-mediated immunity, which involves key players in immune response to the disease, is higher in the summer. This seasonal pattern is supported by evidence from animal models and studies conducted on human subjects.