Study to Evaluate Safety and Immunogenicity of COVID-19 Vaccine in Children 6 Months to < 12 Years

COVID-19 Clinical Trial

— COVID-19  

Official title:

A Phase 2/3 Age De-escalating Study to Evaluate the Safety and Immunogenicity of a SARS-CoV-2 Recombinant Spike Protein Vaccine (SARS-CoV-2 rS) With Matrix-M™ Adjuvant in Children 6 Months to < 12 Years of Age

Clinical Trial Details — Status: Active, not recruiting

Administrative data

• NCT number: NCT05468736
• Other study ID #: 2019nCoV-503
• Status: Active, not recruiting
• Phase: Phase 2/Phase 3
• Start date: July 22, 2022
• Est. completion date: September 8, 2025

Study information

• Verified date: January 2024
• Source: Novavax
• Contact: n/a
• Is FDA regulated: No
• Study type: Interventional

Clinical Trial Summary

This is a Phase 2/3 randomized, observer-blinded, placebo-controlled, age de-escalation trial to evaluate the safety and immunogenicity of 2 primary doses and a booster dose of NVX CoV2373 given 21 days apart in pediatric participants (3 age cohorts; 6 to < 12 years, 2 to < 6 years, and 6 to < 24 months of age). Each age cohort will be conducted in 2 parts starting with the oldest age cohort (6 to < 12 years of age).

Description:

This is a Phase 2/3 randomized, observer-blinded, placebo-controlled, age de-escalation trial to evaluate the safety and immunogenicity of 2 primary doses and a booster dose of NVX CoV2373 given 21 days apart in pediatric participants (3 age cohorts). Each age cohort will be conducted in 2 parts starting with the oldest age cohort (6 to < 12 years of age).

Part 1 will enroll approximately 120 healthy or medically stable sentinel participants per age cohort (10% of the intended enrollment population per age cohort, for a total of 360 sentinel participants overall) who will be randomized in a 1:1 ratio to receive 2 doses of NVX-CoV2373 or placebo with doses given 21 days apart.

Part 2 will enroll a larger number of healthy or medically stable participants (N= approximately 1,080 per age cohort), for a total of approximately 3,240 pediatric participants enrolled in Part 2, and a total of approximately 3,600 participants enrolled in the entire trial). Initial randomization in Part 2 will be in a 2:1 ratio, and the safety and effectiveness of 2 doses of NVX-CoV2373 given 21 days apart will be assessed.

Recruitment information / eligibility

• Status: Active, not recruiting
• Enrollment: 3600
• Est. completion date: September 8, 2025
• Est. primary completion date: November 13, 2023
• Accepts healthy volunteers: Accepts Healthy Volunteers
• Gender: All
• Age group: 6 Months to 11 Years

Eligibility

Inclusion Criteria:

To be included in this study, each individual must satisfy all of the following criteria:

1. Pediatric participants 6 months to < 12 years of age at randomization, determined to be healthy or medically stable by the investigator (based on review of health status, vital signs [to include body temperature], medical history, and targeted physical examination [to include body weight]). Vital signs must be within the normal range prior to the first vaccination, according to the child's age, sex, weight, and height/length.

2. For children from 6 months to < 12 months of age: born at full-term (= 37 weeks gestation) with a minimum birth weight of 2.5 kilograms (kg).

3. Participant and parent(s)/caregiver(s) or legally acceptable representative willing and able to give informed consent and assent, as required, prior to study enrollment and to comply with study procedures.

4. Participants of childbearing potential (defined as any participant who has experienced menarche and who is NOT surgically sterile [ie, hysterectomy, bilateral tubal ligation, or bilateral oophorectomy]) must agree to be heterosexually inactive from at least 28 days prior to enrollment and through 3 months after the last vaccination OR agree to consistently use a highly effective contraception method from at least 28 days prior to enrollment and through 3 months after the last vaccination.

5. Agree not to participate in another SARS-CoV-2 prevention trial for the duration of the study.

Exclusion Criteria:

If an individual meets any of the following criteria, he or she is ineligible for this study:

1. Any acute illness/infection (according to investigator judgment) on the day of vaccination or febrile illness (temperature = 100.4°F [= 38.0°C]). A prospective subject should not be included in the study until the condition has resolved or the febrile event has subsided.

2. Unstable acute or chronic illness. Criteria for unstable medical conditions include:

1. Substantive changes in chronic prescribed medication (change in class or significant change in dose) in the past 2 months.

2. Currently undergoing workup of undiagnosed illness that could lead to a diagnosis of a new condition.

NOTE: Well-controlled human immunodeficiency virus [HIV] infection with undetectable HIV ribonucleic acid [RNA < 50 copies/mL] and CD4 count > 200 cells/µL for at least 1 year, documented within the last 6 months, is NOT considered an unstable chronic illness. Participant's or parent's/caregiver's verbal report will suffice as documentation.

3. Participation in research involving an investigational product (drug/biologic/device) administered within 45 days prior to the first study vaccination.

4. History of a previous laboratory-confirmed diagnosis of SARS-CoV-2 infection or COVID-19.

5. Prior administration of an investigational, authorized, or approved Coronavirus vaccine (ie, against either SARS-CoV, SARS-CoV-2, or MERS CoV) or expected receipt during the period of study follow-up.

6. Previous or current diagnosis of MIS-C.

7. Receipt of medications intended to prevent or treat COVID-19.

8. Received any vaccine within 14 days prior to first study vaccination or planned receipt of any vaccine before Day 49 (ie, 28 days after the second vaccination), except for influenza vaccination, which may be received > 14 days prior to or > 14 days after any study vaccination.

9. Known or suspected congenital or acquired immunodeficiency or autoimmune disease/condition; or receipt of immunosuppressive therapy, such as anti-cancer chemotherapy or radiation therapy; or long-term systemic corticosteroid therapy (prednisone or equivalent for > 14 continuous days) within 90 days prior to first study vaccination. NOTE: An immunosuppressant dose of glucocorticoid is defined as a systemic dose = 20 mg of prednisone per day or equivalent. The use of topical, inhaled, and nasal glucocorticoids is permitted. Topical tacrolimus and ocular cyclosporin are permitted. Stable autoimmune endocrine disorders (eg, thyroiditis, pancreatitis), including stable diabetes mellitus type 1, or participants with a history of Kawasaki disease are NOT excluded.

10. Received immunoglobulin or blood-derived products within 90 days prior to first study vaccination.

11. Active cancer (malignancy) on chemotherapy within 1 year prior to first study vaccination (with the exception of malignancy cured via excision, at the discretion of the investigator).

12. Any known allergies to products contained in the investigational product.

13. Participants who are breastfeeding a child, pregnant or who plan to become pregnant within 3 months following the last study vaccination.

14. Any other condition that, in the opinion of the investigator, would pose a health risk to the participant if enrolled or could interfere with the evaluation of the trial vaccine or interpretation of study results.

15. Study team member or first-degree relative of any study team member (inclusive of Sponsor, and study site personnel involved in the study).

16. Current participation in any other COVID-19 prevention clinical trial.

17. Participants with a history of myocarditis or pericarditis.

Related Conditions & MeSH terms

• COVID-19

Intervention

Biological:
• Biological/Vaccine: SARS-CoV-2 rS/Matrix-M1 Adjuvant (Initial Vaccination Period)
Alternating intramuscular (deltoid) injections of SARS-CoV-2 rS co-formulated with Matrix-M1 adjuvant (0.5 mL) (or fractional dose if necessary) on Days 0 and 21 in the Initial Vaccination Period.
• SARS-CoV-2 rS/Matrix-M1 Adjuvant (Open Label Crossover Vaccination period)
Alternating intramuscular (deltoid) injections of SARS-CoV-2 rS co-formulated with Matrix-M1 adjuvant (0.5 mL) on Day 201 and Day 229 for the participants originally randomized to placebo.
• SARS-CoV-2 rS/Matrix-M1 Adjuvant (Booster Vaccination)
In Booster Vaccination period, one dose of intramuscular (deltoid) injection of SARS-CoV-2 rS co-formulated with Matrix-M1 adjuvant (0.5 mL) on Day 0

Other:
• Placebo
Alternating intramuscular (deltoid) injections of placebo (0.5 mL) on Days 0 and 21 in the Initial Vaccination Period or on Days 201 or Day 229 in the Booster Vaccination Period

Locations

Country	Name	City	State
Colombia	Clinica de la costa	Barranquilla	Atlantico
Colombia	Centro de Estudios en Infectologia Pediatrica S.A.S.CEIP	Cali	Valle Del Cauca
Colombia	Fundacion Oftalmologica de Santander - FOSCAL	Floridablanca	Santander
Colombia	Fundacion Centro de Investigacion Clinica - CIC	Medellin	Antioquia
Colombia	Centro de Atencion e Investigacion Medica S.A.S-CAIMED	Puente Aranda	Bogota
Colombia	Centro de Atencion e Investigacion Medica - CAIMED	Yopal	Casanare
Dominican Republic	Instituto Dermatologico y Cirugia de Piel Dr. Huberto Bogaert Diaz IDCP	Santo Domingo	Distrito Nacional
Dominican Republic	MEDYVAC INTERNACIONAL SRL en Clinica Cruz Jiminian	Santo Domingo	Distrito Nacional
Dominican Republic	PROBEBE en Hospital Universitario Maternidad Nuestra Senora de la Altagracia	Santo Domingo	Distrito Nacional
Dominican Republic	Registrum Group (Hospital Materno Infantil San Lorenzo de Los Mina)	Santo Domingo	Distrito Nacional
Dominican Republic	Registrum Group (Hospital Regional Marcelino Velez)	Santo Domingo	Distrito Nacional
Guatemala	CECLISA	Guatemala
Guatemala	Centro de Investigaciones Pediátricas (CIP)	Guatemala
Guatemala	SMI (Servicios Medicos Integrales)	Guatemala
Honduras	DEMEDICA	San Pedro Sula	Cortés
Honduras	Inverime S.A.	Tegucigalpa	Francisco Morazan
Honduras	Investigacion Sin Limites	Tegucigalpa	Francisco Morazan
Mexico	Panamerican Clinical Research, Mexico S.A de C.V.	Cuernavaca	Morelos
Mexico	Panamerican Clinical Research S.A de C.V.	Guadalajara	Jalisco
Mexico	Centro Multidisciplinario para el Desarrollo Especializado de la Investigacion Clinica en Yucatan S.C.P.	Mérida	Yucatan
Mexico	Panamerican Clinical Research Mexico S.A. de C.V. (Queretaro Site)	Queretaro
Mexico	Clinical Research Institute S.C.	Tlalnepantla
Mexico	Innovacion y Desarrollo en Ciencias de la Salud (IDeCSa)	Tlalpan	Mexico City
Mexico	Instituto Nacional de Ciencias Medicas y Nutricion Salvador Zubiran	Tlalpan	Ciudad De Mexico
Mexico	FAICIC S. de R.L. de C.V.	Veracruz
Philippines	Medical Mission Group Hospital-Lucban and Southern Luzon State University	Lucena	Quezon
Philippines	Manila Doctors Hospital	Manila	Metro Manila
Philippines	University of the Philippines - Philippine General Hospital	Manila	Metro Manila
Philippines	FEU-NRMF	Quezon City	Metro Manila
Philippines	National Children's Hospital	Quezon City	Metro Manila
Philippines	University of the Philippines Manila - National Institutes of Health (NIH) - Institute of	San Juan	Batangas
South Africa	Tiervlei Trial Centre	Bellville	Western Cape
South Africa	REIMED Riger Park	Boksburg	Gauteng
South Africa	Setshaba Research Centre	Ga-Tshwene	Gauteng
South Africa	Soweto Clinical Trials Centre	Johannesburg	Gauteng
South Africa	Wits Vida Nkanyezi Site- Rahima Moosa Mother and Child Hospital	Johannesburg	Gauteng
South Africa	WiWits RHI - Shandukani Research Centre	Johannesburg	Gauteng
South Africa	Be Part Yoluntu Centre - Paarl	Paarl	Western Cape
South Africa	Wits Vida- Chris Hani Baragwanath Hospital	Soweto	Gauteng
South Africa	Limpopo Clinical Research Initiative	Thabazimbi	Limpopo
South Africa	Stellenbosch University Worcester	Worcester	Western Cape
Spain	Hospital Universitario Severo Ochoa	Leganés	Madrid
Spain	Hospital Universitario 12 de Octubre	Madrid
Spain	Complejo Hospitalario Universitario de Santiago	Santiago de Compostela	A Coruña
Spain	Hospital Universitario de Torrejon	Torrejon de Ardoz	Madrid
United Kingdom	Lakeside Healthcare Research	Corby	Northamptonshire
United Kingdom	St Georges Hospital	London
United States	Advanced Research Center	Anaheim	California
United States	Morehouse School of Medicine	Atlanta	Georgia
United States	Velocity Clinical Research	Beachwood	Ohio
United States	Tekton Research Beaumont	Beaumont	Texas
United States	Coast Clinical Research, LLC	Bellflower	California
United States	Imagine Research of Palm Beach County	Boynton Beach	Florida
United States	Palm Harbor Dermatology PA	Brandon	Florida
United States	Craig A. Spiegel, M.D.	Bridgeton	Missouri
United States	PanAmerican Clinical Research	Brownsville	Texas
United States	Tekton Research - Atlanta	Chamblee	Georgia
United States	WR - ClinSearch, LLC	Chattanooga	Tennessee
United States	South Texas Clinical Research	Corpus Christi	Texas
United States	Velocity Clinical Research - Covington	Covington	Louisiana
United States	Velocity Clinical Research - Covington, LA	Covington	Louisiana
United States	Dayton Clinical Research	Dayton	Ohio
United States	Bay Colony Pediatrics	Dickinson	Texas
United States	Apex Research Group	Fair Oaks	California
United States	Velocity Clinical Research Grants Pass	Grants Pass	Oregon
United States	Tribe Clinical Research	Greenville	South Carolina
United States	Corning Center for Clinical Research	Horseheads	New York
United States	Mercury Clinical Research	Houston	Texas
United States	Trio Clinical Trials	Houston	Texas
United States	Leavitt Clinical Research	Idaho Falls	Idaho
United States	Westside Center for Clinical Research	Jacksonville	Florida
United States	Velocity Clinical Research - Lafayette LA	Lafayette	Louisiana
United States	Alliance for Multispecialty Research	Layton	Utah
United States	Michael W. Simon, M.D., PSC	Lexington	Kentucky
United States	Be Well Clinical Studies, LLC	Lincoln	Nebraska
United States	Meridian Clinical Research	Lincoln	Nebraska
United States	Preferred Research Partners, Inc.	Little Rock	Arkansas
United States	Ark Clinical Research	Long Beach	California
United States	Bluegrass Clinical Research, Inc./All Children Pediatrics	Louisville	Kentucky
United States	Cordova Research Institute, LLC	Miami	Florida
United States	Boeson Research	Missoula	Montana
United States	Clinical Research Associates, Inc.	Nashville	Tennessee
United States	Orange County Research Institute	Ontario	California
United States	ARS-Nona Pediatric Center	Orlando	Florida
United States	Research Your Health	Plano	Texas
United States	Clinical Research Partners, LLC	Richmond	Virginia
United States	Mercury Clinical Research - Pediatric Center	Richmond	Texas
United States	Alliance for Multispecialty Research c/o Wee Care Pediatrics - Roy	Roy	Utah
United States	Tekton Research	San Antonio	Texas
United States	California Research Foundation	San Diego	California
United States	Senders Pediatrics	South Euclid	Ohio
United States	Lynn Institute of Tulsa	Tulsa	Oklahoma
United States	Clinical Research of California	Walnut Creek	California
United States	Velocity Clinical Research - West Jordan	West Jordan	Utah

Sponsors (1)

Lead Sponsor	Collaborator
Novavax

Countries where clinical trial is conducted

United States,  Colombia,  Dominican Republic,  Guatemala,  Honduras,  Mexico,  Philippines,  South Africa,  Spain,  United Kingdom, 

Outcome

Type	Measure	Description	Time frame	Safety issue
Primary	Reactogenicity Incidence and Severity	Reactogenicity incidence, duration, and severity (mild, moderate, severe, or potentially life-threatening) recorded by parent(s)/caregiver(s) on an electronic patient-reported outcome diary application (eDiary) on days of vaccination and subsequent 6 days (total 7 days after each vaccine injection).	Day 0 to Day 7
Primary	Incidence and Severity of Medically Attended Adverse Events (MAAEs)	Incidence and severity of MAAEs through 28 days after second injection of each set of vaccinations (initial and crossover), and after a booster dose.	Day 0 to Day 28
Primary	Incidence and Severity of Unsolicited Adverse Events (AEs)	Incidence and severity of unsolicited AEs through 28 days after second injection of each set of vaccinations (initial and crossover), and after a booster dose.	Day 0 to Day 28
Primary	Incidence and Severity of MAAEs Attributed to Study Vaccine	Incidence and severity of MAAEs attributed to study vaccine after initial vaccination at Day 0 through Month 24 or the EoS.	Day 0 to Day 730
Primary	Incidence and Severity of Serious Adverse Events (SAEs)	Incidence and severity of SAEs after initial vaccination at Day 0 through Month 24 or the EoS.	Day 0 to Day 730
Primary	Incidence and Severity of Adverse Events of Special Interest (AESIs)	Incidence and severity of AESIs (including multisystem inflammatory syndrome in children [MIS-C], and myocarditis and/or pericarditis) after initial vaccination at Day 0 through Month 24 or the EoS.	Day 0 to Day 730
Primary	Death due to any cause	Death due to any cause occurring from Day 0 to EoS.	Day 0 to Day 730
Secondary	Participants with PCR positive mild, moderate or severe COVID-19 after the primary series of 2 doses	Incidence rate of participants with first episode of PCR-positive mild, moderate, or severe COVID-19 overall and per age cohort, with or without positive anti-NP serology at baseline after the primary series of 2 doses.	Day 0 to Day 730
Secondary	Participants with PCR positive moderate or severe COVID-19 after the primary series of 2 doses	Incidence rate of participants with first episode of PCR-positive moderate or severe COVID-19 overall and per age cohort, with or without positive anti-NP serology at baseline, and by risk factors to develop severe COVID-19 after the primary series of 2 doses.	Day 0 to Day 730
Secondary	Participants with diagnostic test - positive asymptomatic, mild, moderate or severe COVID-19 after the primary series of 2 doses	Incidence rate of participants with first episode of diagnostic test-positive asymptomatic, mild, moderate, or severe COVID-19 (regardless of confirmatory test used, ie, PCR or rapid antigen test, and of testing location, ie, central or externally tested) overall and per age cohort, with or without positive anti-NP serology at baseline after the primary series of 2 doses.	Day 0 to Day 730
Secondary	Participants with diagnostic test - positive moderate or severe COVID-19 after the primary series of 2 doses	Incidence rate of participants with first episode of diagnostic test-positive moderate or severe COVID-19 (regardless of confirmatory test used, ie, PCR or rapid antigen test, and of testing location, ie, central or externally tested) overall and per age cohort, with or without positive anti NP serology at baseline, and by risk factors to develop severe COVID-19 after the primary series of 2 doses.	Day 0 to Day 730
Secondary	Participants with PCR positive mild, moderate or severe COVID-19 after the booster dose	Incidence rate of participants with first episode of PCR-positive mild, moderate, or severe COVID-19 overall and per age cohort, with or without positive anti-NP serology at baseline after the booster dose.	Day 0 to Day 730
Secondary	Participants with PCR positive moderate or severe COVID-19 after the booster dose	Incidence rate of participants with first episode of PCR-positive moderate or severe COVID-19 overall and per age cohort, with or without positive anti-NP serology at baseline, and by risk factors to develop severe COVID-19 after the booster dose.	Day 0 to Day 730
Secondary	Participants with diagnostic test - positive asymptomatic, mild, moderate or severe COVID-19 after the booster dose	Incidence rate of participants with first episode of diagnostic test-positive asymptomatic, mild, moderate, or severe COVID-19 (regardless of confirmatory test used, ie, PCR or rapid antigen test, and of testing location, ie, central or externally tested) overall and per age cohort, with or without positive anti-NP serology at baseline after the booster dose.	Day 0 to Day 730
Secondary	Participants with diagnostic test moderate or severe COVID-19 after the booster dose	Incidence rate of participants with first episode of diagnostic test-positive moderate or severe COVID-19 (regardless of confirmatory test used, ie, PCR or rapid antigen test, and of testing location, ie, central or externally tested) overall and per age cohort, with or without positive anti-NP serology at baseline after the booster dose, and by risk factors to develop severe COVID-19.	Day 0 to Day 730
Secondary	Antibodies to SARS-CoV-2 Nucleoprotein (NP) at Specified Time Points	Antibodies to SARS-CoV-2 NP, regardless of whether the infection was symptomatic. Antibodies to SARS-CoV-2 NP at Days 0 and 35, at Crossover Visit 1, at Booster vaccination visit, and at Months 12 and 24 will be used to determine natural infection and to determine the incidence of asymptomatic infection acquired during study follow-up.	Day 0 to Day 730
Secondary	Neutralizing antibody response, post-booster, by age cohort,seronegative to anti-SARS-CoV-2 NP antibodies at baseline and pre-booster	Neutralizing antibody response at 28 days post booster for pediatric participants in the Immunogenicity Population overall and by age cohort, seronegative to anti-SARS-CoV-2 NP antibodies at baseline and pre-booster, compared with that observed at 28 days post-booster vaccination in young adult participants 18 to < 26 years of age.	Day 0 to Day 28
Secondary	Neutralizing antibody response, by age cohort, regardless of serostatus at baseline and pre-booster	Neutralizing antibody response at 28 days post-booster for pediatric participants in the Immunogenicity Population overall and by age cohort, regardless of serostatus at baseline and pre-booster, compared with that observed in pediatric participants at baseline (Day 0).	Day 0 to Day 28
Secondary	Serum IgG levels to SARS-CoV-2 S protein, post-booster, by age cohort, regardless of serostatus at baseline and pre-booster vaccination	Serum IgG levels to SARS-CoV-2 S protein at 28 days post-booster vaccination for pediatric participants in the Immunogenicity Population overall and by age cohort, regardless of serostatus at baseline and pre-booster vaccination, compared with that observed at 28 days post-booster vaccination in young adult participants 18 to < 26 years of age.	Day 0 to Day 28
Secondary	Serum IgG levels to SARS-CoV-2 S protein, post booster, by age cohort, regardless of serostatus at baseline and pre-booster	Serum IgG levels to SARS-CoV-2 S protein at 28 days post-booster for pediatric participants in the Immunogenicity Population overall and by age cohort, regardless of serostatus at baseline and pre-booster, compared with that observed in pediatric participants at baseline (Day 0).	Day 0 to Day 28
Secondary	Serum IgG levels to SARS-CoV-2 S protein , post booster, by age cohort, regardless of serostatus at baseline and pre-booster	Serum IgG levels to SARS-CoV-2 S protein at 28 days post-booster for pediatric participants in the Immunogenicity Population overall and by age cohort, regardless of serostatus at baseline and pre-booster, compared with that observed in pediatric participants at Day 35,	Day 0 to Day 35
Secondary	Percentage of pediatric participants by age cohort reporting SARS-CoV-2 infection (COVID-19) by severity	Proportion of pediatric participants by age cohort reporting SARS-CoV-2 infection (COVID-19) from Day 28 through 6 months, from Day 28 through end of Month 12, from Day 28 through EOS, from 6 months through end of Month 12, and from 6 months through EOS, by severity classification.	Day 28 to Day 730
Secondary	Neutralizing antibody response in the Immunogenicity Population	Neutralizing antibody response at Day 35 for pediatric participants in the Immunogenicity Population by age cohort and with and without anti-SARS-CoV 2 NP antibodies at baseline.	Day 35
Secondary	Serum IgG levels to SARS-CoV-2 S protein after second injection of the initial vaccination series	Serum IgG levels to SARS-CoV-2 S protein 14 days after second injection of the initial vaccination series (Day 35) in pediatric participants in the Immunogenicity Population by age cohort and subsets with and without anti-NP antibodies at baseline.	Day 35
Secondary	Treatment and severity of COVID 19 after a PCR-confirmed case	Description of course, treatment and severity of COVID 19 reported after a PCR-confirmed case via the Case Form.	Day 0 to Day 730
Secondary	Antibodies to SARS-CoV-2 NP, regardless of whether the infection was symptomatic.	Antibodies to SARS-CoV-2 NP, regardless of whether the infection was symptomatic. Antibodies to SARS-CoV-2 NP at Days 0 and 35, at Crossover Visit 1, at Booster vaccination visit, and at Months 12 and 24 will be used to determine natural infection and to determine the incidence of asymptomatic infection acquired during study follow-up.	Day 0 to Day 730
Secondary	Serum IgG levels to SARS-CoV-2 S protein expressed as GMT	Serum IgG levels to SARS-CoV-2 S protein at Months 6 (pre- booster), 7/8 (1-month post-booster), 12, and 24 post-vaccination with NVXCoV2373.	Day 180 to Day 730
Secondary	MN titers to SARS-CoV-2 S protein expressed as GMT	MN titers at Months 6 (pre- booster), 7/8 (1-month post-booster), 12, and 24 post-vaccination with NVXCoV2373.	Day 180 to Day 730