The phrase "affect the severity or" is correct and usable in written English.
It can be used in contexts discussing how certain factors influence the intensity or seriousness of a situation or condition.
Example: "The medication may affect the severity or duration of the symptoms experienced by the patient."
Alternatives: "influence the intensity of" or "impact the seriousness of".
However, in vitro toxicity tests, clinical data, and morphometry-assisted histopathological analyses yielded no evidence of any toxic or otherwise adverse local or systemic effects of CMS, nor did they affect the severity or course of atopic dermatitis.
Knocking out SPARC expression did affect the severity or onset of disease (data not shown).
Co-immunization with hGPI325-339 APL APL 15, an agonistic APL, however, did not affect the severity or course of arthritis.
Injection of either wild-type or IFN-γR KO MSCs at day -1 did not affect the severity or incidence of arthritis, whereas injection of Treg cells did reduce the severity of CIA.
Because the genetic background in maize can dramatically affect the severity, or even presence, of the mutant phenotype, F2 populations from crosses to inbreds where the mutant phenotype is consistent and easy to score will be very helpful.
Factors that increase the risk of polio infection or affect the severity of the disease include immune deficiency, malnutrition, physical activity immediately following the onset of paralysis, skeletal muscle injury due to injection of vaccines or therapeutic agents, and pregnancy.
Importantly, the experiments presented establish that changes in the activity of any one of three major signaling components – Nrf2, Maf-S or Keap1 – affect the severity of PD symptoms in the Drosophila α-synuclein model, offering multiple unique opportunities for drug development.
Immunity gained from infection in the first wave or vaccination will affect the severity of the second wave.
What you eat (or, as you'll see, what you don't eat) can affect the severity of your jet lag-induced malaise.
However, mast cell deficiency did not affect the severity of IBD triggered by non-steroidal anti-inflammatory agents (NSAID) exposure or helicobacter infection that also affect intestinal permeability.
