Trial Outcomes & Findings for Study to Evaluate the Safety, Tolerability, and Immunogenicity of an RNA Vaccine Candidate Against COVID-19 in Healthy Children (NCT NCT04816643)

The study consisted of 2 parts, Phase 1 and Phase 2/3.

Out of 11837 participants enrolled, 11760 were vaccinated.

Study to Evaluate the Safety, Tolerability, and Immunogenicity of an RNA Vaccine Candidate Against COVID-19 in Healthy Children

Local reactions were collected in electronic diary (e-diary) or during unscheduled clinical assessments from Day 1 to 7 after Dose 1. Redness and swelling were measured and recorded in measuring device unit (mdu) where, 1 mdu = 0.5 centimeter (cm) and were graded as mild (\>=0.5 to 2.0 cm), moderate (\>2.0 to 7.0 cm), severe (\>7.0 cm) and Grade 4 (necrosis \[redness and swelling\] or exfoliative dermatitis \[redness\]). Pain at injection site was graded as mild (did not interfere with activity), moderate (interfered with activity), severe (prevented daily activity) and Grade 4 Emergency room (ER) visit or hospitalization). Grade 4 reactions were classified by investigator or medically qualified person. Reactions reported as adverse events in case report form within 7 days of study vaccination also included. Two-sided 95% confidence interval was based on Clopper and Pearson method.

Local reactions were collected in e-diary or during unscheduled clinical assessments from Day 1 to Day 7 after Dose 2. Redness and swelling were measured and recorded in mdu where, 1 mdu =0.5 cm and were graded as mild (\>=0.5 to 2.0 cm), moderate (\>2.0 to 7.0 cm), severe (\>7.0 cm) and Grade 4 (necrosis \[redness and swelling\] or exfoliative dermatitis \[redness\]). Pain at injection site was graded as mild (did not interfere with activity), moderate (interfered with activity), severe (prevented daily activity) and Grade 4 ER visit or hospitalization. Grade 4 reactions were classified by investigator or medically qualified person. Reactions reported as adverse events in case report form within 7 days of study vaccination were also included. Two-sided 95% CI was based on Clopper and Pearson method.

Local reactions were collected in e-diary or during unscheduled clinical assessments from Day 1 to Day 7 after Dose 3. Redness and swelling were measured and recorded in mdu where, 1 mdu =0.5 cm and were graded as mild (\>=0.5 to 2.0 cm), moderate (\>2.0 to 7.0 cm), severe (\>7.0 cm) and Grade 4(necrosis \[redness and swelling\] or exfoliative dermatitis \[redness\]). Pain at injection site was graded as mild (did not interfere with activity), moderate (interfered with activity), severe (prevented daily activity) and Grade 4 ER visit or hospitalization. Grade 4 reactions were classified by investigator or medically qualified person. Reactions reported as adverse events in case report form within 7 days of study vaccination also included. Two-sided 95% CI was based on Clopper and Pearson method.

Systemic events were recorded in an e-diary and at unscheduled clinical assessments from Day 1 to Day 7 after Dose 1. Fever: oral temperature \>= 38.0 degree Celsius (deg C); categorized as \>=38.0 deg C, 38.0 to 38.4 deg C, \>38.4 to 38.9 deg C, \>38.9 to 40.0 deg C and \>40.0 deg C. Fatigue, headache, chills, new or worsened muscle pain \& new or worsened joint pain: mild (did not interfere with activity), moderate (some interference with activity), severe (prevented daily routine activity). Vomiting: mild:1-2 times in 24 hours, moderate: \>2 times in 24 hours; severe: required intravenous hydration. Diarrhea: mild: 2-3 loose stools in 24 hours, moderate: 4-5 loose stools in 24 hours, severe: 6 or more loose stools in 24 hours. Grade 4 for all events: except fever; ER visit/hospitalization and were classified by investigator or medically qualified person. Events reported as AEs in CRF within 7 days after vaccination were included. Exact 95% CI based on Clopper and Pearson method.

Systemic events were recorded in an e-diary and at unscheduled clinical assessments from Day 1 to Day 7 after Dose 2. Fever: oral temperature \>= 38.0 C; categorized as \>=38.0 deg C, 38.0 to 38.4 deg C, \>38.4 to 38.9 deg C, \>38.9 to 40.0 deg C and \>40.0 deg C. Fatigue, headache, chills, new or worsened muscle pain \& new or worsened joint pain: mild (did not interfere with activity), moderate (some interference with activity), severe (prevented daily routine activity). Vomiting: mild:1-2 times in 24 hours, moderate: \>2 times in 24 hours; severe: required intravenous hydration. Diarrhea: mild: 2-3 loose stools in 24 hours, moderate: 4-5 loose stools in 24 hours, severe: 6 or more loose stools in 24 hours. Grade 4 for all events: except fever; ER visit/hospitalization and were classified by investigator or medically qualified person. Events reported as AEs in CRF within 7 days after vaccination were included. Exact 95% CI based on Clopper and Pearson method.

Systemic events were recorded in an e-diary and at unscheduled clinical assessments from Day 1 to Day 7 after Dose 3. Fever: oral temperature \>= 38.0 C; categorized as \>=38.0 deg C, 38.0 to 38.4 deg C, \>38.4 to 38.9 deg C, \>38.9 to 40.0 deg C and \>40.0 deg C. Fatigue, headache, chills, new or worsened muscle pain \& new or worsened joint pain: mild (did not interfere with activity), moderate (some interference with activity), severe (prevented daily routine activity). Vomiting: mild:1-2 times in 24 hours, moderate: \>2 times in 24 hours; severe: required intravenous hydration. Diarrhea: mild: 2-3 loose stools in 24 hours, moderate: 4-5 loose stools in 24 hours, severe: 6 or more loose stools in 24 hours. Grade 4 for all events: except fever; ER visit/hospitalization and were classified by investigator or medically qualified person. Events reported as AEs in CRF within 7 days after vaccination were included. Exact 95% CI based on Clopper and Pearson method.

Local reactions were collected in e-diary or during unscheduled clinical assessments from Day 1 to Day 7 after Dose 1. Redness and swelling were measured and recorded in mdu where, 1 mdu =0.5 cm and were graded as mild (\>=0.5 to 2.0 cm), moderate (\>2.0 to 7.0 cm), severe (\>7.0 cm) and Grade 4 (necrosis \[redness and swelling\] or exfoliative dermatitis \[redness\]). Pain at injection site was graded as mild (did not interfere with activity), moderate (interfered with activity), severe (prevented daily activity) and Grade 4 ER visit or hospitalization. Grade 4 reactions were classified by investigator or medically qualified person. Reactions reported as adverse events in case report form within 7 days of study vaccination were also included. Two-sided 95% CI was based on Clopper and Pearson method.

Local reactions were collected in e-diary or during unscheduled clinical assessments from Day 1 to Day 7 after Dose 2. Redness and swelling were measured and recorded in mdu where, 1 mdu =0.5 cm and were graded as mild (\>=0.5 to 2.0 cm), moderate (\>2.0 to 7.0 cm), severe (\>7.0 cm) and Grade 4 (necrosis \[redness and swelling\] or exfoliative dermatitis \[redness\]). Pain at injection site was graded as mild (did not interfere with activity), moderate (interfered with activity), severe (prevented daily activity) and Grade 4 ER visit or hospitalization. Grade 4 reactions were classified by investigator or medically qualified person. Reactions reported as adverse events in case report form within 7 days of study vaccination were also included. Two-sided 95% CI was based on Clopper and Pearson method.

Local reactions were collected in e-diary or during unscheduled clinical assessments from Day 1 to Day 7 after Dose 3. Redness and swelling were measured and recorded in mdu where, 1 mdu =0.5 cm and were graded as mild (\>=0.5 to 2.0 cm), moderate (\>2.0 to 7.0 cm), severe (\>7.0 cm) and Grade 4 (necrosis \[redness and swelling\] or exfoliative dermatitis \[redness\]). Pain at injection site was graded as mild (did not interfere with activity), moderate (interfered with activity), severe (prevented daily activity) and Grade 4 ER visit or hospitalization. Grade 4 reactions were classified by investigator or medically qualified person. Reactions reported as adverse events in case report form within 7 days of study vaccination were also included. Two-sided 95% CI was based on Clopper and Pearson method.

Systemic events were recorded in an e-diary and at unscheduled clinical assessments from Day 1 to Day 7 after Dose 1. Fever: oral temperature \>= 38.0 C; categorized as \>=38.0 deg C, 38.0 to 38.4 deg C, \>38.4 to 38.9 deg C, \>38.9 to 40.0 deg C and \>40.0 deg C. Fatigue, headache, chills, new or worsened muscle pain \& new or worsened joint pain: mild (did not interfere with activity), moderate (some interference with activity), severe (prevented daily routine activity). Vomiting: mild:1-2 times in 24 hours, moderate: \>2 times in 24 hours; severe: required intravenous hydration. Diarrhea: mild: 2-3 loose stools in 24 hours, moderate: 4-5 loose stools in 24 hours, severe: 6 or more loose stools in 24 hours. Grade 4 for all events: except fever; ER visit/hospitalization and were classified by investigator or medically qualified person. Events reported as AEs in CRF within 7 days after vaccination were included. Exact 95% CI based on Clopper and Pearson method.

Systemic events were recorded in an e-diary and at unscheduled clinical assessments from Day 1 to Day 7 after Dose 2. Fever: oral temperature \>= 38.0 C; categorized as \>=38.0 deg C, 38.0 to 38.4 deg C, \>38.4 to 38.9 deg C, \>38.9 to 40.0 deg C and \>40.0 deg C. Fatigue, headache, chills, new or worsened muscle pain \& new or worsened joint pain: mild (did not interfere with activity), moderate (some interference with activity), severe (prevented daily routine activity). Vomiting: mild:1-2 times in 24 hours, moderate: \>2 times in 24 hours; severe: required intravenous hydration. Diarrhea: mild: 2-3 loose stools in 24 hours, moderate: 4-5 loose stools in 24 hours, severe: 6 or more loose stools in 24 hours. Grade 4 for all events: except fever; ER visit/hospitalization and were classified by investigator or medically qualified person. Events reported as AEs in CRF within 7 days after vaccination were included. Exact 95% CI based on Clopper and Pearson method.

Systemic events were recorded in an e-diary and at unscheduled clinical assessments from Day 1 to Day 7 after Dose 3. Fever: oral temperature \>= 38.0 C; categorized as \>=38.0 deg C, 38.0 to 38.4 deg C, \>38.4 to 38.9 deg C, \>38.9 to 40.0 deg C and \>40.0 deg C. Fatigue, headache, chills, new or worsened muscle pain \& new or worsened joint pain: mild (did not interfere with activity), moderate (some interference with activity), severe (prevented daily routine activity). Vomiting: mild:1-2 times in 24 hours, moderate: \>2 times in 24 hours; severe: required intravenous hydration. Diarrhea: mild: 2-3 loose stools in 24 hours, moderate: 4-5 loose stools in 24 hours, severe: 6 or more loose stools in 24 hours. Grade 4 for all events: except fever; ER visit/hospitalization and were classified by investigator or medically qualified person. Events reported as AEs in CRF within 7 days after vaccination were included. Exact 95% CI based on Clopper and Pearson method.

Local reactions were collected in e-diary or during unscheduled clinical assessments from Day 1 to Day 7 after Dose 1. Redness and swelling were measured and recorded in mdu where, 1 mdu =0.5 cm and were graded as mild (\>=0.5 to 2.0 cm), moderate (\>2.0 to 7.0 cm), severe (\>7.0 cm) and Grade 4 (necrosis \[redness and swelling\] or exfoliative dermatitis \[redness\]). Tenderness at injection site was graded as mild (hurts if gently touched), moderate (hurts if gently touched with crying), severe (causes limitation of limb movement) and Grade 4 ER visit or hospitalization. Grade 4 reactions were classified by investigator or medically qualified person. Reactions reported as adverse events in case report form within 7 days of study vaccination were also included. Two-sided 95% CI was based on Clopper and Pearson method.

Local reactions were collected in e-diary or during unscheduled clinical assessments from Day 1 to Day 7 after Dose 2. Redness and swelling were measured and recorded in mdu where, 1 mdu =0.5 cm and were graded as mild (\>=0.5 to 2.0 cm), moderate (\>2.0 to 7.0 cm), severe (\>7.0 cm) and Grade 4 (necrosis \[redness and swelling\] or exfoliative dermatitis \[redness\]). Tenderness at injection site was graded as mild (hurts if gently touched), moderate (hurts if gently touched with crying), severe (causes limitation of limb movement) and Grade 4 ER visit or hospitalization. Grade 4 reactions were classified by investigator or medically qualified person. Reactions reported as adverse events in case report form within 7 days of study vaccination were also included. Two-sided 95% CI was based on Clopper and Pearson method.

Local reactions were collected in e-diary or during unscheduled clinical assessments from Day 1 to Day 7 after Dose 3. Redness and swelling were measured and recorded in mdu where, 1 mdu =0.5 cm and were graded as mild (\>=0.5 to 2.0 cm), moderate (\>2.0 to 7.0 cm), severe (\>7.0 cm) and Grade 4 (necrosis \[redness and swelling\] or exfoliative dermatitis \[redness\]). Tenderness at injection site was graded as mild (hurts if gently touched), moderate (hurts if gently touched with crying), severe (causes limitation of limb movement) and Grade 4 ER visit or hospitalization for severe tenderness at injection site). Grade 4 reactions were classified by investigator or medically qualified person. Reactions reported as adverse events in case report form within 7 days of study vaccination were also included. Two-sided 95% CI was based on Clopper and Pearson method.

Systemic events recorded in an e-diary and at unscheduled clinical assessments from Day 1 to 7 after Dose 1. Fever: oral temperature \>= 38.0 C; categorized as \>=38.0 deg C, 38.0 to 38.4 deg C, \>38.4 to 38.9 deg C, \>38.9 to 40.0 deg C and \>40.0 deg C. Decreased appetite: mild (decreased interest in eating), moderate (decreased oral intake), severe (refusal to feed). Drowsiness: mild (increased or prolonged sleeping bouts), moderate (slightly subdued interfering with daily activity), severe (disabling; not interested in usual daily activity). Irritability: mild (easily consolable), moderate (requiring increased attention), severe (Inconsolable; crying cannot be comforted). Grade 4 for all events except fever: ER visit/hospitalization and were classified by investigator or medically qualified person. Events reported as AEs in the CRF within 7 days after vaccination were also included. Exact 95% CI based on Clopper and Pearson method.