In recent years, several studies revealed that the current influenza vaccine strategy might be of minimal vaccine effectiveness and had a smaller effect on reducing morbidity and mortality in the end-stage renal disease population than previously thought. Thus, this also raised the question about the effectiveness of administration of influenza vaccination in chronic kidney disease patients not on dialysis. In this study, the investigators aim to evaluate the effectiveness of seasonal trivalent influenza vaccine, formulation 2013-2014, in patients with different stage of chronic kidney disease (CKD) not on dialysis.

The purpose of this study is to evaluate the antibody response to each of the three influenza vaccine strains included in the licensed seasonal flu vaccine, as measured by the method of hemagglutination inhibition (HI) and ELISA-based microneutralization (microNT-ELISA) assays. All participants will be divided into 3 groups: participants refused to receive vaccination, those receive either one (week 0) or one more booster vaccination (week 0 and week 4). The investigators will collect serum of participants at the 5th weeks, 9th weeks, and 21th week post vaccination and evaluate the difference of immune response in these 3 groups.

Inclusion Criteria:

1. .Males and non-pregnant females and aged ≥ 18 years with chronic kidney disease not on dialysis;
2. .Willing and able to adhere to visit schedules and all study requirements;
3. .Subjects read and signed the study-specific informed consent.
4. .Subjects who has either received the first dose of 2013-2014 seasonal influenza vaccination before or not.

Exclusion Criteria:

1. .Subject or his/her family is employed by the participated hospital;
2. .History of hypersensitivity to eggs or egg protein or similar pharmacological effects to study medication;
3. .Personal or family history of Guillain-Barré Syndrome;
4. .An acute febrile illness within 1 week prior to vaccination;
5. .Current upper respiratory illness, including the common cold or nasal congestion within 72 hours;
6. .Subjects with influenza-like illness as defined by the presence of fever (temperature ≥ 38°C) and at least two of the following four symptoms: headache, muscle/joint aches and pains (e.g. myalgia/arthralgia), sore throat and cough;
7. .Female subjects who are pregnant during the study.
8. .Treatment with an investigational drug or device, or participation in a clinical study, within 3 months before consent;
9. .Immunodeficiency, or under immunosuppressive treatment.
10. .Receipt of any vaccine within 1 week prior to study vaccination or expected receipt between Visit 1 (study vaccination) and Visit 2 (final collection of blood samples);
11. .Receipt of any blood products, including immunoglobulin in the prior 3 months;
12. .Any severe illness needed to be hospitalization within three months.
13. .Underlying condition in the investigators' opinion may interfere with evaluation of the vaccine.