- Parasitic infection is a serious public health problem throughout the world particularly in developing countries including Egypt. The individuals infected with helminths are responding to the parasite infections by a specific Th2 type innate and adaptive immune responses. The Coronavirus Disease 2019 pandemic has affected over 169 million people and caused the death of millions worldwide. COVID vaccines with up to 95% of efficacy and effectiveness have been developed and approved by the Food and Drug Administration (FDA), USA. Moreover, it's reported that vaccination against COVID may lead to Cytokine Storm Syndrome in some vaccinated people with release of large amounts of cytokines as (IFNγ, IL-12, TNFα).

• Parasitic infection is a serious public health problem throughout the world particularly in developing countries including Egypt.
• Stool examination and CBC(complete blood count) are considered as the most easily, affordable and accessible diagnostic tool to suspect the presence of parasitic infection.
• One of the most important laboratory findings in many helminthic and protozoan infections is the high rate of peripheral blood eosinophilia. Giardia lamblia cause increased number of lymphocytes.
• The individuals infected with helminths are responding to the parasite infections by a specific Th2 type innate and adaptive immune responses. The Th2 pattern cytokines predominate in long-term helminth infected individuals.
• During chronic helminths infection, there is increased production of interleukin-4 (IL-4) and interleukin-10 (IL-10) as anti-inflammatory cytokines, as well as increased activation and expansion of eosinophils, mast cells and basophils.
• In addition, IFNγ have an important inflammatory role in many protozoan parasites as Cryptosporidium, Microsporidia, Entamoeba histolytica.
• The Coronavirus Disease 2019 pandemic has affected over 169 million people and caused the death of millions worldwide. COVID vaccines with up to 95% of efficacy and effectiveness have been developed and approved by the Food and Drug Administration (FDA), USA.
• Moreover, it's reported that vaccination against COVID may lead to Cytokine Storm Syndrome in some vaccinated people with release of large amounts of cytokines as (IFNγ, IL-12, TNFα).

Inclusion Criteria:

• Vaccinated and non-vaccinated individuals with COVID-19 vaccines who are known to have different parasitic infections (helminths and protozoan) and admitted to Assiut city hospitals.

Exclusion Criteria:

• Bleeding disorders that may alter CBC results.

Vaccinated and non-vaccinated individuals with COVID-19 vaccines who are known to have different parasitic infections (helminths and protozoan) and admitted to Assiut city hospitals.