Main populations in need of EV and RSV treatments

Both EV and RSV infections are known to primarily affect vulnerable populations. These groups include newborns, young children, the elderly, immunosuppressed patients, and those with certain coexisting diseases such as chronic respiratory diseases. The specifics of the vulnerability of these at-risk groups are summarized below:

Newborns and young children
Newborns and young children are particularly susceptible to severe illnesses from RSV. The WHO states that each year more than 3 million children under the age of 5 are hospitalized due to RSV infections, and nearly 60,000 children in this age group die each year.

“Each year more than 3 million children under the age of 5 are hospitalized due to RSV infections”

Newborns, young children and teenagers may encounter complications from EV infections, although most children experience uncomplicated EV infections. Of note, however, is the fact that EV can lead to sepsis in some newborns, which can lead to organ failure and death. A large age group of children are susceptible to developing CNS infections (meningitis and encephalitis), which can lead to lasting symptoms. Furthermore, EV has been identified as a causative agent for type 1 diabetes.

Elderly
On the other end of the spectrum, aging is associated with an increase in chronic disorders and age-related diseases (e.g., cardiovascular disease) that may negatively affect a subject’s resistance to infections.

In addition, aging is associated with a weakening of the immune system (immunosenescence). During immunosenescence, the ability to protect against infections and cancer is compromised, wound healing and the immune response to vaccination are all impaired while both the inflammatory response and the risk of chronic inflammation are enhanced.

“177,000 elderly people are hospitalized and 14,000 die from RSV each year in the US alone”

Two cardinal features of immunosenescence linked to infection are an increased susceptibility to respiratory infections and the reactivation of chronic viral infections. The older demographic continues to grow, and it has been estimated that the world’s elderly population (>65 years) will exceed 1.5 billion in 2050. For this group, infection is the reason behind a third of the deaths. The CDC states that about 177,000 elderly people are hospitalized and 14,000 die from RSV each year in the US alone (these figures are acknowledged as likely to be underestimated).

Immunosuppressed subjects
Immunodeficiency is characterized by a malfunctioning immune system. This is due to either genetics (primary immunodeficiency) or immunosuppressive changes (secondary or acquired immunodeficiency). The prevalence of immunodeficiency is increasing due to a growing and aging population.

“There are about 6 million people with primary immunodeficiency and the prevalence of secondary immunodeficiency is considerably greater”

There are about 6 million people with primary immunodeficiency. The prevalence of secondary immunodeficiency is considerably greater, comprising patients with immunodeficiency due to factors such as aging, HIV, chemotherapy, and malnutrition. Immunodeficient subjects are at increased risk of complications from what are regarded as mild and uncomplicated infections in healthy individuals. For example, RSV pneumonia in immunocompromised adults is associated with a mortality rate of 11–78% depending on the severity of the immunosuppression.