vaccines for covid-19 are gold strategy and great achievement at this century for protection against complications of covid-19 , development of many vaccines with different technology represent a big challenge for this disease so the world live bad days and the vaccines save world to see the light once again , mRNA based vaccines have a new technology which designed before for cancer therapy, this technology is very effective , producible and fast for future disease targets but these vaccine must contain excipients for preservation of this technology mRNA so we now study these side effects of excipients and we suspect that polyethylene glycol as excipients have big role at hypoglycemic effects with antidiabetic medications like metformin and insulin especially at children and older age

diabetics patients as chronic diseases represent high percentage at all the world and high priority for vaccines against covid-19 so we will focus on these group as need more attention and need best health and quality of life so my study concentrate on diabetics patients from 12 years to 80 years who were taken mRNA based vaccines and suffer from recurrent hypoglycemia , i will check the blood glucose one month after the first or second injection of mRNA based vaccines Pfizer or moderna vaccines and study all medicines taken by patients and suspect what's happen is there is hypoglycemic effect or nor by following up the readings of blood glucose by glucometers or CGM

there are previous studies about relation of metformin and polyethylene glycol injection and this study conclude that The subcutaneous injection of PEX168 once a week can effectively, continuously and safely improve HbA1c levels in patients with T2D when combined with metformin ( Gao F, Lv X, Mo Z, Ma J, Zhang Q, Yang G, Liu W, Li Q, Zhou J, Bao Y, Jia W. Efficacy and safety of polyethylene glycol loxenatide as add-on to metformin in patients with type 2 diabetes: A multicentre, randomized, double-blind, placebo-controlled, phase 3b trial. Diabetes Obes Metab. 2020 Dec;22(12):2375-2383. doi: 10.1111/dom.14163. Epub 2020 Sep 6. PMID: 32744358.

Inclusion Criteria:

- Male and female subjects between the ages of 12 and 80 years, inclusive, with Type 1 or 2 diabetes mellitus as defined by the American Diabetes Association (Diabetes care, Vol. 21: S5- S19, 1998) for more than one year.

Exclusion Criteria:

• under 12 years above 80 years undergone bariatric surgery no exercises during testing

The study population is a group of individuals selected on the basis of inclusion and exclusion criteria which relate to the variables being studied. It is the population from which the sample population will be randomly or purposively selected