Booster Vaccination Against COVID-19

Inclusion Criteria:

- Signed informed consent

- Healthy male or female aged 18 - 60 years (including both groups)

- Subjects who were vaccinated with CoronaVac for 2 doses and who had a minimum of 90
days and a maximum of 270 days after the second dose

- Subjects may have a controlled or moderate comorbidity

- Female subjects of childbearing potential should be willing to ensure that they or
their partner use effective birth control methods continuously from 1 month before and
up to 3 months after vaccination

- Subjects agreed to comply with all study requirements

- Subjects are willing to share their medical history with their physician and allow
access to all medical records when relevant to study procedures

- Subjects are willing to agree to abstain from donating blood during the study

Exclusion Criteria:

Subjects meeting any of the following criteria will be excluded from the study:

- Administration of any vaccine (registered or investigational) other than study
intervention within 30 days before and after each study vaccine (one week for
authorized seasonal flu vaccine or pneumococcal vaccine)

- Positive for COVID-19 after primary vaccination

- Pre-or planned use of another vaccine or product likely to affect the study (e.g.
adenovirus vectored vaccines, any coronavirus vaccine)

- Subjects who were pregnant at the time of enrollment or who plan to become pregnant
within the first 3 months following vaccination and who are breastfeeding

- Subjects with fever (above 38°C) at the time of vaccination and/or up to 72 hours
before

- Administration of immunoglobulins and/or any blood product within 3 months prior to
vaccination

- Any confirmed or suspected immunosuppressive or immunodeficiency state; asplenia;
recurrent severe infections and use of immunosuppressants (less than ≤14 days) in the
last 6 months, excluding topical steroids or short-term oral steroids

- Possible history of allergic disease or reaction (e.g. to the active substance) by any
component of the study vaccines

- Any history of anaphylaxis

- Current cancer diagnosis or treatment (excluding basal cell carcinoma of the skin and
cervical carcinoma in situ)

- History of bleeding disorder (e.g. factor deficiency, coagulopathy or platelet
disorder), or prior history of significant bleeding or bruising following
intramuscular injections or venipuncture

- Continued use of anticoagulants such as coumarins and related anticoagulants (i.e.
warfarin) or new oral anticoagulants (i.e. apixaban, rivaroxaban, dabigatran and
edoxaban)

- Cerebral venous sinus thrombosis, antiphospholipid syndrome, or a history of
heparin-induced thrombocytopenia and thrombosis (HITT or HIT type 2).

- Suspected or known current alcohol or drug addiction

- Any other significant disease, disorder or finding that could significantly increase
the subject's risk for participation in the study, affect the subject's ability to
participate in the study, or impair the interpretation of study data; severe and/or
uncontrolled cardiovascular disease, respiratory disease, gastrointestinal disease,
liver disease, kidney disease, endocrine disorder, and neurological disease
(mild/moderate well-controlled comorbidities are permitted)

- History of active or previous autoimmune neurological disorders (e.g. multiple
sclerosis, Guillain-Barre syndrome, transverse myelitis) (Bell's palsy will not be an
exclusion criterion)

- Subjects with severe renal impairment or liver failure

- Subjects who will undergo scheduled elective surgery during the study

- Subjects with a life expectancy of less than 6 months

- Subject who participated in another clinical trial study involving an investigational
product in the past 12 weeks

- In case of clinical necessity, a COVID-19 PCR (polymerase chain reaction) test will be
requested from the subjects, and subjects who are positive will be excluded from the
study

- Known history of SARS-CoV-2 infection

- Acute respiratory disease (moderate or severe illness with or without fever) (Subjects
may be screened again after acute condition has resolved)

- Fever (oral temperature > 37.8°C) (Subjects can be enrolled again after acute
condition improves)

- Insufficient level of Turkish to perform the informed consent, except where briefing
by an independent witness can be provided and is available