The goal of this clinical trial is to assess the immunogenicity, efficacy and safety of the Convacell vaccine in healthy adult volunteers aged 18 years and older. The main questions it aims to answer are: * To assess the immunogenicity and safety of single and double dose intramuscular administration of the Convacell vaccine; * To assess the epidemiological effectiveness of the Convacell vaccine in the prevention of SARS-CoV-2 infection and development of severe COVID-19 compared with placebo when single or double intramuscular injection.
The trial will be conducted in two stages (Stage IIb and Stage III). • Stage IIb Participants will be vaccinated one dose or two doses of the Convacell vaccine. Investigators will compare one dose and two doses groups and will choose the best vaccine dosage regimen in terms of immunogenicity and safety. • Stage III Participants will be vaccinated the Convacell vaccine or Placebo. Investigators will use the dosage regimen chosen in IIb stage.
Study Type
INTERVENTIONAL
Allocation
RANDOMIZED
Purpose
PREVENTION
Masking
DOUBLE
Enrollment
16,304
solution for intramuscular injection, 0.5 ml
solution for intramuscular injection, 0.5 ml
Limited Liability Company "OLLA-MED"
Moscow, Russia
State budgetary health care institution of the city of Moscow "City Clinical Hospital No. 24 of the Department of Health of the City of Moscow"
Moscow, Russia
Limited Liability Company "Scientific Research Center Eco-Safety"
Saint Petersburg, Russia
St. Petersburg State Budgetary Health Institution "City Polyclinic No. 117"
Saint Petersburg, Russia
Limited Liability Company "Otkrytaya Meditsina"
Tolyatti, Russia
Limited Liability Company "Meditsinskiy Diagnosticheskiy Tsentr"
Yaroslavl, Russia
Change in titer of IgG antibodies to N-protein of SARS-CoV-2 (Stage IIb)
Outcome Measure is analyzed separately in the 18-60 and \>60 age subgroups.
Time frame: Days 0, 42
Frequency of symptomatic COVID-19 with laboratory-confirmed infection within 6 months after vaccination compared with the placebo group (Stage III)
Laboratory confirmation of SARS-CoV-2 infection in accordance with current clinical guidelines can be a PCR study or an antigen test of a swab from the nasopharynx or oropharynx. The symptomatic form of COVID-19 is the presence of at least one of the following symptoms: fever/chills, cough, shortness of breath or difficulty breathing, fatigue, muscle or body pain, headache, loss of the sense of taste or smell, sore throat, nasal congestion or runny nose, nausea or vomiting, diarrhea. Outcome Measure is analyzed separately in the 18-60 and \>60 age subgroups.
Time frame: Days 0-180 (6 months)
Change in titer of IgM antibodies to N-protein of SARS-CoV-2 on day 42 after initial vaccination (Stage IIb)
Outcome Measure is analyzed separately in the 18-60 and \>60 age subgroups.
Time frame: Days 0, 42
Proportion of SARS-CoV-2 seropositive participants on day 42 after initial vaccination (Stage IIb)
Outcome Measure is analyzed separately in the 18-60 and \>60 age subgroups.
Time frame: Days 0, 42
Change in titer of IgG antibodies to N-protein of SARS-CoV-2 on day 42 after initial vaccination (Stage IIb)
Outcome Measure is analyzed separately in the 18-60 and \>60 age subgroups.
Time frame: Days 0, 42
The frequency of seroconversion (appearance of specific antibodies to SARS-CoV-2 N-protein) on day 42 after initial vaccination (Stage IIb)
Outcome Measure is analyzed separately in the 18-60 and \>60 age subgroups.
Time frame: Days 0, 42
Change from Baseline in the Mean Specifically Sensitized T-lymphocytes (Stage IIb)
Outcome Measure is analyzed separately in the 18-60 and \>60 age subgroups.
Time frame: Days 0, 42
Number of volunteers hospitalized with COVID-19 (Stage IIb)
* Total number of SARS-CoV-2 infection cases (laboratory-confirmed) * Total number of COVID-19 cases (laboratory-confirmed) * Total number of COVID-19 related deaths Outcome Measure is analyzed separately in the 18-60 and \>60 age subgroups.
Time frame: through trial Stage IIb; Days 0-49
Frequency of laboratory confirmed asymptomatic SARS-CoV-2 infections within 6 months. after initial vaccination compared with the placebo group (Stage III)
Outcome Measure is analyzed separately in the 18-60 and \>60 age subgroups.
Time frame: Days 0-180 (6 months)
Frequency of laboratory-confirmed severe COVID-19 (Stage III)
Frequency of laboratory-confirmed severe COVID-19 in accordance with current criteria * RR \> 30/min * Blood oxygen saturation (SpO2) ≤ 93% * Oxygenation index (PaO2 /FiO2) ≤ 300 mmHg * Decreased level of consciousness, agitation * Unstable hemodynamics (systolic arterial pressure \[SBP\] less than 90 mm Hg. or diastolic blood pressure \[DBP\] less than 60 mmHg, diuresis less than 20 ml/hour) * Lung changes on computed tomography (CT) or radiographs typical for a viral lesion * Arterial blood lactate \> 2 mmol/l * Assessment on a quick scale (quick Sequential Organ Failure Assessment, qSOFA) \> 2 points Outcome Measure is analyzed separately in the 18-60 and \>60 age subgroups.
Time frame: Days 0-180 (6 months)
Overall frequency of all AEs/SAEs (Stage IIb and III)
Outcome Measure is analyzed separately in the 18-60 and \>60 age subgroups.
Time frame: through trial Stage IIb (Days 0-49), through trial Stage III (Days 0-196)
Overall frequency of all AEs/SAEs associated with the study drug (Stage IIb and III)
Outcome Measure is analyzed separately in the 18-60 and \>60 age subgroups.
Time frame: through trial Stage IIb (Days 0-49), through trial Stage III (Days 0-196)
The frequency of local post-vaccination reactions at the injection site (Stage IIb and III)
* Erythema at the injection site (presence/absence); * Soreness (presence/absence), including assessment duration of preservation of pain and its intensity: weak, moderate, strong; * Edema (presence/absence), including diameter infiltrate assessment: weak (up to 2.5 cm), medium (from 2.6 to 5 cm), strong (more than 5 cm or the presence of lymphangitis) reactions; * Enlargement of regional lymph nodes (presence/absence); * Induration at the injection site (presence/absence); * Itching at the injection site (presence/absence). Outcome Measure is analyzed separately in the 18-60 and \>60 age subgroups.
Time frame: Days 0-7 after initial vaccination and revaccination
The frequency of systemic post-vaccination reactions at the injection site (Stage IIb and III)
* Increase in body temperature, including an assessment fever severity: mild (37.3-37.5°C), moderate (37.6-38.5°С) and strong (\> 38.5°С); * Chills; * Deterioration of general health, malaise; * Headache; * Dizziness; * Loss of appetite; * Insomnia; * Nausea, Vomiting, Dyspepsia; * Diarrhea; * Body pain or muscle weakness; * Sweating; * Pain in the joints; * Pain in the abdomen; * Convulsions; * Myalgia; * Enlargement of regional lymph nodes. * Changes in the side of the mucous membranes, the presence of papules, vesicles, erosions. Outcome Measure is analyzed separately in the 18-60 and \>60 age subgroups.
Time frame: Days 0-7 after initial vaccination and revaccination
The frequency of local post-vaccination reactions at the injection site (Stage IIb and III)
Outcome Measure is analyzed separately in the 18-60 and \>60 age subgroups.
Time frame: Days 0-21 after initial vaccination and revaccination
Frequency of systemic post-vaccination reactions (Stage IIb and III)
Outcome Measure is analyzed separately in the 18-60 and \>60 age subgroups.
Time frame: Days 0-42 after initial vaccination
The frequency of toxic post-vaccination complications (Stage IIb and III)
Septic conditions, generalized infection. Outcome Measure is analyzed separately in the 18-60 and \>60 age subgroups.
Time frame: through trial Stage IIb (Days 0-49), through trial Stage III (Days 0-196)
The frequency of allergic post-vaccination complications (Stage IIb and III)
Polymorphous eruption, angioedema, arthralgia, anaphylactic shock. Outcome Measure is analyzed separately in the 18-60 and \>60 age subgroups.
Time frame: through trial Stage IIb (Days 0-49), through trial Stage III (Days 0-196)
The frequency of neurological post-vaccination complications (Stage IIb and III)
Encephalitis, neuritis, polyneuritis. Outcome Measure is analyzed separately in the 18-60 and \>60 age subgroups.
Time frame: through trial Stage IIb (Days 0-49), through trial Stage III (Days 0-196)
The presence of allergic reactions (Stage IIb and III)
Outcome Measure is analyzed separately in the 18-60 and \>60 age subgroups.
Time frame: through trial Stage IIb (Days 0-49), through trial Stage III (Days 0-196)
Сhange in white blood cell count and relative white blood cell count (Stage IIb)
Outcome Measure is analyzed separately in the 18-60 and \>60 age subgroups.
Time frame: Day 0 (screening), day 28 ± 2 (visit 4)
Сhange in neutrophils count and relative neutrophils count (Stage IIb)
Outcome Measure is analyzed separately in the 18-60 and \>60 age subgroups.
Time frame: Day 0 (screening), day 28 ± 2 (visit 4)
Сhange in lymphocytes count and relative lymphocytes count (Stage IIb)
Outcome Measure is analyzed separately in the 18-60 and \>60 age subgroups.
Time frame: Day 0 (screening), day 28 ± 2 (visit 4)
Сhange in monocyte count and relative monocyte count (Stage IIb)
Outcome Measure is analyzed separately in the 18-60 and \>60 age subgroups.
Time frame: Day 0 (screening), day 28 ± 2 (visit 4)
Сhange in the IgE level (Stage IIb)
Outcome Measure is analyzed separately in the 18-60 and \>60 age subgroups.
Time frame: Day 0 (screening), day 28 ± 2 (visit 4)
The proportion of participants with delayed post-vaccination reactions (percent) (Stage IIb and III)
Outcome Measure is analyzed separately in the 18-60 and \>60 age subgroups.
Time frame: through trial Stage IIb (Days 0-49), through trial Stage III (Days 0-196)
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