Vaccine Info

NVX-CoV2373 COVID-19 Vaccine

Last Reviewed
January 18, 2021

NVX-CoV2373 COVID-19 Vaccine Description

NVX-CoV2373 is a prefusion protein coronavirus vaccine candidate made using Novavax’s proprietary nanoparticle technology, Matrix-M, an adjuvant to enhance immune responses and stimulate high levels of neutralizing antibodies.

Novavax’s patented saponin-based Matrix-M adjuvant has demonstrated a potent and well-tolerated effect by stimulating the entry of antigen-presenting cells into the injection site and enhancing antigen presentation in local lymph nodes, boosting immune response and helping an immunized person make antibodies against the virus.

Novavax identified NVX‑CoV2373 as its lead COVID-19 candidate following pre-clinical testing that demonstrated high immunogenicity and high levels of neutralizing antibodies.

A Phase 1 clinical trial of NVX‑CoV2373 initiated in Australia during May 2020. On August 4, 2020, Novavax announced the Phase 1 data from its Phase 1/2 clinical trial found the recombinant COVID-19 vaccine candidate adjuvanted with Matrix-M was generally well-tolerated elicited robust antibody responses numerically superior to that seen in human convalescent sera.

All subjects in this study developed anti-spike IgG antibodies after a single dose of vaccine. Many of them also developed wild-type virus-neutralizing antibody responses. After Dose 2, 100% of participants developed wild-type virus-neutralizing antibody responses. Both anti-spike IgG and viral neutralization responses compared favorably to responses from patients with clinically significant COVID‑19 disease.

Importantly, the IgG antibody response was highly correlated with neutralization titers, demonstrating that a significant proportion of antibodies were functional. This study was published on August 6, 2020.

And, the adjuvant was dose-sparing, with the lower 5 µg dose of NVX‑CoV2373 performing comparably with the 25 µg dose. Cellular immune responses were measured in a subset of participants, and NVX‑CoV2373 induced antigen-specific polyfunctional CD4+ T cell responses with a strong bias toward the Th1 phenotype (IFN-g, IL-2, and TNF-a).

On September 2, 2020, the New England Journal of Medicine published further detail on the previously announced results. NVX‑CoV2373 demonstrated a reassuring safety and reactogenicity profile and induced robust antibody responses numerically superior to that seen in human convalescent sera.

The Phase 2 portion will assess immunity, safety, and COVID-19 disease reduction in up to 1,500 volunteers in the USA and Australia, with approximately 50 percent between 60 and 84 years of age.

A Phase 3, Randomized, Stratified, Observer-Blind, Placebo-Controlled Study to Evaluate the Efficacy, Safety, and Immunogenicity of mRNA-1273 SARS-CoV-2 Vaccine in Adults Aged 18 Years and Older was last updated on October 28, 2020.

The federal government awarded Novavax $1.6 billion as part of Operation Warp Speed (OWS). Novavax uses the OWS funding to complete late-stage clinical development, including a pivotal Phase 3 clinical trial; establish large-scale manufacturing, and delivering 100 million doses of NVX‑CoV2373 beginning as early as late 2020.

The Coalition for Epidemic Preparedness Innovations is also investing up to $388 million, and the Department of Defense is investing up to $60 million of funding to advance the clinical development of NVX‑CoV2373.

As of September 24, 2020, Novavax stated it 'has continued to scale-up its manufacturing capacity, currently at up to 2 billion annualized doses, once all capacity has been brought online by mid-2021.'

On November 4, 2020, Novavax confirmed various supply agreements with the USA, the United Kingdom, Canada, Australia, and partnerships with Japan, South Korea, and India.

And a press statement issued on November 30, 2020, “Novavax is in a leading position to significantly contribute to the need for safe and efficacious vaccines that will ultimately end the worldwide COVID-19 pandemic,” said Stanley C. Erck, CEO, Novavax. “We continue to make meaningful progress as we work to test, manufacture, and ultimately deliver NVX-CoV2373 with unprecedented speed, as well as put partnerships in place that would ensure widespread and equitable access worldwide.”

On December 10, 2020, the NEJM published a review, which found 'At 35 days, NVX-CoV2373 appeared to be safe, and it elicited immune responses that exceeded levels in Covid-19 convalescent serum. The Matrix-M1 adjuvant-induced CD4+ T-cell responses were biased toward a Th1 phenotype.'

Furthermore, 'The primary safety and immunogenicity analyses indicate that in healthy adult participants 18 to 59 years of age, two-dose regimens of 5 μg and 25 μg of rSARS-CoV-2 plus the Matrix-M1 adjuvant had acceptable safety findings and induced high immune responses, with levels of neutralizing antibodies that closely correlated with anti-spike IgG. Furthermore, after the second vaccination with rSARS-CoV-2 plus Matrix-M1, neutralizing antibody responses exceeded values seen in symptomatic Covid-19 outpatients and were of the magnitude seen in convalescent serum from hospitalized patients with Covid-19.'

On December 28, 2020, NIAID Director Anthony S. Fauci, M.D., said in a press statement, “The launch of this study, the fifth investigational COVID-19 vaccine candidate to be tested in a Phase 3 trial in the USA, demonstrates our resolve to end the pandemic through the development of multiple safe and effective vaccines.”

On January 6, 2021, Karen Kotloff, M.D., stated in a University of Maryland School of Medicine press release, “This virus has not been democratic. We have seen that it has impacted minorities, the elderly, and people with certain medical conditions the hardest. So an important goal of this research is to learn about the safety and effectiveness of the vaccine in these groups."

On January 7, 2021, Novavax stated 'it is currently conducting late-stage clinical studies to demonstrate the efficacy, safety, and immunogenicity of NVX-CoV2373 to prevent COVID-19. This includes two large pivotal Phase 3 clinical trials in the United States/Mexico (the PREVENT-19 trial) and the United Kingdom, as well as a Phase 2b trial in South Africa.'

“The continued increase in significant COVID-19 transmission in virtually all parts of the world underscores the need for multiple safe, efficacious vaccines in enormous quantities to stop the pandemic,” added Stanley C. Erck, Novavax President and Chief Executive Officer. “We appreciate the confidence of the Australian government and the opportunity to play a role in ensuring that its citizens will have access to a protein-based vaccine that can be distributed using existing distribution channels, should it receive regulatory approval.”

Novavax previously announced it was awarded $1.6 billion in funding from the U.S. government to meet its Operation Warp Speed goals to expedite the delivery of millions of doses of safe, effective vaccines for COVID-19. The award is funding the U.S. and Mexico pivotal Phase 3 trial and manufacturing scale-up. 

Maryland based Novavax, Inc. is a leading innovator of recombinant vaccines; its proprietary recombinant technology platform combines the power and speed of genetic engineering to efficiently produce highly immunogenic nanoparticles to address urgent global health needs.

NVX-CoV2373 COVID-19 Vaccine Indication

NVX-CoV2373 is a vaccine candidate indicated as a SARS-CoV-2 coronavirus vaccine to prevent COVID-19 disease. In preclinical trials, NVX-CoV2373 demonstrated efficient binding with receptors targeted by the virus, a critical aspect for effective vaccine protection.

No pediatric, pregnancy or oncology vaccine efficacy has been disclosed.

NVX-CoV2373 COVID-19 Vaccine Dosage

Novavax evaluated two intramuscular immunizations of 5 and 25 μg NVX Cov2373, with and without its Matrix-M adjuvant, in a Phase I trial. NVX-CoV2373 was reported stable and will allow handling in a liquid formulation that can be stored at 2°C to 8°C, allowing for successful cold chain management with existing infrastructure.

NVX-CoV2373 COVID-19 Vaccine News

January 11, 2021 - Howard University Joins Novavax Phase 3 Clinical Trial of NVX-CoV2373 Vaccine Candidate Against COVID-19. “We believe that diverse participation in COVID-19 trials will go a long way toward encouraging potentially life-saving vaccination when it is available,” said President Wayne A. I. Frederick, M.D., MBA, a practicing surgeon at Howard University Hospital. “Along with following COVID-19 prevention guidelines, effective vaccination is the most promising approach to mitigating and ending the pandemic. Our goal through participation is to ensure a safe and effective product is developed to address the needs of Black, Latino, and other minority communities.”

January 11, 2021 - Illinois-based Baxter International Inc. announced that Baxter BioPharma Solutions has agreed to provide sterile manufacturing services for NVX-CoV2373, Novavax’ COVID-19 recombinant nanoparticle vaccine candidate with Matrix-M™ adjuvant. The agreement is expected to advance commercial-scale manufacturing essential for the vaccine’s production and distribution in the United Kingdom and European markets. Baxter’s manufacturing services for NVX-CoV2373 will take place at its facility in Halle/Westfalen, Germany. 

January 7, 2021 - Novavax, Inc. announced that it had executed an Advance Purchase Agreement with the Commonwealth of Australia for 51 million doses of NVX-CoV2373, Novavax’ COVID-19 vaccine candidate. This follows an agreement in principle that was announced in November 2020. 

January 6, 2021 - Researchers at the University of Maryland School of Medicine will participate in a Phase 3 clinical trial of an investigational COVID-19 vaccine to protect against SARS-CoV-2, the coronavirus causing COVID-19 that continues to impact millions of people around the world. The clinical trial will test the safety and effectiveness of NVX-CoV2373, being developed by U.S. biotechnology company Novavax, Inc., based in Gaithersburg, MD.

December 28, 2020 - Novavax said Monday it is starting a late-stage trial of its COVID-19 vaccine candidate NVX-CoV2373, with plans to enroll up to 30,000 volunteers at about 115 sites the U.S. and Mexico. The trial will be randomized, placebo-controlled, and evaluate the treatment's efficacy in patients aged 18 and older. “We’ve come this far, this fast, but we need to get to the finish line,” said NIH Director Francis S. Collins, M.D., Ph.D. “That will require multiple vaccines using different approaches to ensure everyone is protected safely and effectively from this deadly disease.”

December 16, 2020 - Novavax, Inc. announced an Advance Purchase Agreement with New Zealand's government to purchase 10.7 million doses of NVX-CoV2373, Novavax’s candidate vaccine against COVID-19. Under the terms of the agreement, Novavax will manufacture NVX-CoV2373 with a target of delivering initial doses by mid-2021. The company will work with Medsafe, New Zealand’s regulatory agency, to obtain product approvals as needed.

December 10, 2020 - Study published by the NEJM: Phase 1–2 Trial of a SARS-CoV-2 Recombinant Spike Protein Nanoparticle Vaccine.

November 30, 2020 - The company announced 2 of the three planned late-stage efficacy trials for NVX-CoV2373 sponsored by Novavax are fully enrolled, and more than 20,000 participants have been dosed to-date. The primary efficacy endpoints for these trials have been harmonized and reviewed by global regulatory agencies to facilitate regulatory approval and ensure that the results are generalizable across global populations.

November 10, 2020 - Novavax released its federal contract in a quarterly financial filing with the Securities and Exchange Commission. 

November 9, 2020 - Novavax, Inc. announced that the U.S. FDA had granted Fast Track Designation for NVX-CoV2373, the Company’s COVID-19 vaccine candidate, a stable, prefusion protein made using Novavax’ nanoparticle technology and includes its proprietary MatrixM™ adjuvant. Novavax said it expects to begin its pivotal Phase 3 clinical trial in the USA and Mexico by the end of November.

November 4, 2020 - Novavax, Inc. announced the signing of a non-binding Heads of Terms document with the Australian Government to supply 40 million doses of the Company’s COVID-19 vaccine candidate, NVX-CoV2373, for the Australian community.

October 27, 2020 - Novavax, Inc. announced updates on its Phase 3 clinical development program of NVX-CoV2373. The Company also announced that it would present data from its ongoing Phase 1/2 clinical trial, including new Phase 2 reactogenicity data, on October 30, 2020, during the U.S. Center for Disease Control and Prevention’s Advisory Committee on Immunization Practices meeting.

September 25, 2020 - Endo International plc announced that its subsidiary, Par Sterile Products, LLC (Par Sterile), has entered into a non-exclusive agreement with Novavax, Inc fill-finish manufacturing services at its plant in Rochester, Michigan for NVX-CoV2373, Novavax' COVID-19 vaccine candidate.

September 24, 2020 - Novavax, Inc. announced that it had initiated its first Phase 3 study to evaluate the efficacy, safety, and immunogenicity (NVX-CoV2373, Novavax’ COVID-19 vaccine candidate. The trial is being conducted in the United Kingdom (UK), in partnership with the UK Government’s Vaccines Taskforce. It is expected to enroll and immunize up to 10,000 individuals between 18-84 years of age, with and without relevant comorbidities, over the next four to six weeks.

September 15, 2020 - Novavax announced an amendment to its existing agreement with Serum Institute of India Private Limited (SIIPL) under which SIIPL will also manufacture the antigen component of NVX‑CoV2373, Novavax’ COVID‑19 vaccine candidate. With this agreement, Novavax increases its manufacturing capacity of NVX-CoV2373 to over 2-billion doses annually, when all planned capacity has been brought online by mid-2021.

September 10, 2020 - Novavax, Inc. announced it would participate in five upcoming investor conferences. A topic of discussion will be Novavax’s COVID-19 vaccine candidate, NVX-CoV2373.

September 8, 2020 - Nine CEOs sign a historic pledge to continue to make the safety and well-being of vaccinated individuals the top priority in the development of the first COVID-19 vaccines.

September 2, 2020 - Novavax announced the publication in The New England Journal of Medicine of Phase 1 data from its Phase 1/2 clinical trial of NVX‑CoV2373, its COVID‑19 vaccine candidate. The publication offers further detail on the previously announced results. NVX‑CoV2373 demonstrated a reassuring safety and reactogenicity profile and induced robust antibody responses numerically superior to that seen in human convalescent sera.

August 31, 2020 - Novavax, Inc. announced it had reached an agreement in principle with the Government of Canada to supply up to 76 million doses of NVX-CoV2373, Novavax’ COVID-19 vaccine candidate. Maryland-based Novavax stated that Novavax expects to supply doses of NVX-CoV2373 to Canada as early as the second quarter of 2021.

August 24, 2020 - Novavax announced that the first volunteers had been enrolled in the Phase 2 portion of its ongoing clinical trial to evaluate the immunogenicity and safety of NVX-CoV2373, Novavax’ COVID-19 vaccine candidate. The Phase 2 clinical trial expands on the age range of the Phase 1 portion by including older adults 60-84 years of age as approximately 50 percent of the trial’s population.

August 17, 2020 - Novavax, Inc. announced the beginning of a Phase 2b clinical trial in South Africa to evaluate the efficacy of NVX-CoV2373; Novavax’ COVID-19 vaccine candidate uses proprietary nanoparticle technology and includes Novavax’ proprietary Matrix‑M™ adjuvant. Dr. Shabir Madhi, Professor of Vaccinology at Wits University, will lead the clinical trial supported in part by a $15 million grant from the Bill & Melinda Gates Foundation. Novavax expects that its COVID-19 vaccine would ultimately be supplied to South Africa through Novavax’s recently announced collaboration with the Serum Institute of India if approved in South Africa.

August 14, 2020 - Novavax, Inc. announced it had signed a Heads of Terms with the Government of the United Kingdom (UK) for the purchase of 60 million doses of NVX-CoV2373, Novavax’ COVID-19 vaccine, and a Phase 3 clinical trial to assess the efficacy of the vaccine in the UK population. Novavax will also expand its collaboration with FUJIFILM Diosynth Biotechnologies, which is expected to produce up to 180 million doses annually in the UK.

August 13, 2020 - Novavax and SK bioscience announced a development and supply agreement for the antigen component of NVX-CoV2373, Novavax’ COVID-19 vaccine candidate, for supply to global markets, including the COVAX Facility. Besides, the companies have signed a letter of intent with the Republic of Korea’s Ministry of Health and Welfare to work toward broad and equitable access to NVX-CoV2373 in South Korea. Under the terms of the agreement, SK bioscience will manufacture the vaccine antigen component for the final drug product globally during the pandemic period.

August 7, 2020 - Novavax and Takeda announced a partnership for developing, manufacturing, and commercializing NVX‑CoV2373, Novavax’ COVID‑19 vaccine candidate, in Japan. NVX‑CoV2373 is a stable, prefusion protein made using Novavax’s recombinant protein nanoparticle technology and includes Novavax’s proprietary Matrix‑M™ adjuvant. Takeda will receive funding from the Government of Japan’s Ministry of Health, Labour and Welfare (MHLW) to support the technology transfer, establishment of infrastructure, and scale-up of manufacturing. Takeda anticipates the capacity to manufacture over 250 million doses of the COVID-19 disease prevention vaccine per year.

August 7, 2020 - Several days after making some headlines with a press release about the data, the Novavax vaccine effort has been published on Medrxiv. The reactions to the vaccine itself look fine. Overall, there seem to be no overt safety signs of causing any concern.

August 6, 2020 - Novavax announced a license agreement with Serum Institute of India Private Limited to develop and commercialize NVX‑CoV2373 in low- and middle-income countries and India. This agreement excludes major upper-middle and high-income countries, for which Novavax continues to retain rights.

August 5, 2020 - NIH-Moderna investigational COVID-19 vaccine shows promise in mouse studies. The vaccine is currently being evaluated in Phase 3 clinical testing.

August 4, 2020 - Novavax announced Phase 1 data from its Phase 1/2 clinical trial of its COVID‑19 vaccine candidate, NVX‑CoV2373.

July 27, 2020 - The US government issued a federal task order reserving production capacity at one of Texas A&M University System College Station's facilities. This task order is valued at about $265 million, announced by the university on July 27, 2020.

July 23, 2020 - Novavax, Inc. and FUJIFILM Diosynth Biotechnologies (FDB) announced today an agreement to manufacture bulk drug substances NVX-CoV2373, Novavax' COVID-19 vaccine candidate. FDB's site in Morrisville, North Carolina, has begun production of the first batch of NVX-CoV2373. 

July 7, 2020 - Novavax, Inc. announced that it has been selected to participate in Operation Warp Speed and has been awarded $1.6 billion by the U.S. federal government to complete late-stage clinical development, including a pivotal Phase 3 clinical trial; establish large-scale manufacturing; and deliver 100 million doses of NVX‑CoV2373, Novavax’ COVID-19 vaccine candidate, as early as late 2020. 

June 15, 2020 - Novavax, Inc. announced that it has agreed to sell Series A Convertible preferred stock that could generate gross proceeds of approximately $200 million.

June 8, 2020 - Novavax announced that Gregory M. Glenn, M.D., President of Research and Development, will join other vaccine industry leaders for a panel discussion at 2020 BIO Digital. “We see neutralizing titers in the 10,000 range in non-human primates." The company expects results and plans to start a Phase II trial and manufacture 100 million doses in 2020.

June 4, 2020 - Novavax announced that the company had been awarded a contract by the U.S. Department of Defense (DoD) to manufacture NVX‑CoV2373, Novavax’ COVID-19 vaccine candidate. NVX‑CoV2373 consists of a stable, prefusion protein antigen made using its proprietary nanoparticle technology and includes Novavax’s proprietary Matrix‑M™ adjuvant.

May 25, 2020 - Novavax, Inc. announced enrollment of the first participants in a Phase 1/2 clinical trial of its coronavirus vaccine candidate, NVX‑CoV2373, a stable, prefusion protein made using its proprietary nanoparticle technology. Preliminary immunogenicity and safety results from the Phase 1 portion of the trial are expected in July 2020.

May 13, 2020 -  Dr. Gregory Glenn's presentation at the World Vaccine Congress regarding NVX-CoV2373 Vaccine for COVID-19.

May 11, 2020 - Novavax, Inc. announced that the Coalition for Epidemic Preparedness Innovations (CEPI) would invest up to $384 million of additional funding, on top of $4 million it invested in March, to advance the clinical development of NVX-CoV2373, Novavax’ coronavirus vaccine candidate against SARS-CoV-2. The additional funding from CEPI will also support the rapid scale-up of the NVX-CoV2373 vaccine antigen and Novavax’s proprietary Matrix-M™ adjuvant, which is expected to enhance immune responses by stimulating high levels of neutralizing antibodies.

April 8, 2020 - Novavax, Inc, announced it had identified a coronavirus vaccine candidate, NVX-CoV2373. The NVX-CoV2373 clinical development plan combines a Phase 1/Phase 2 approach to allow rapid advancement during the current coronavirus pandemic.

March 10, 2020 - CEPI to provide an initial $4 million to accelerate vaccine development to prepare for Phase 1 clinical study.

NVX-CoV2373 COVID-19 Vaccine Clinical Trials

Novavax reported its Phase 1 portion of its Phase 1/2 clinical trial, NVXCoV2373 was generally well-tolerated and elicited robust antibody responses numerically superior to that seen in human convalescent sera. NVX-CoV2373 is also being evaluated in two ongoing Phase 2 studies, which began in August; a Phase 2b trial in South Africa and a Phase 1/2 continuation in the U.S. and Australia.

Clinical Trial NCT04611802: A Phase 3, Randomized, Observer-Blinded, Placebo-Controlled Study to Evaluate the Efficacy, Safety, and Immunogenicity of a SARS-CoV-2 Recombinant Spike Protein Nanoparticle Vaccine (SARS-CoV-2 rS) With Matrix-M1™ Adjuvant in Adult Participants ≥ 18 Years -- Last Update Posted: January 8, 2021.

This clinical trial is now recruiting.

Novavax’s pivotal Phase 3 clinical trial is being conducted with support from the U.S. Government through Operation Warp Speed. The trial design is harmonized with those of other leading companies and calls for the enrollment of up to 30,000 participants in the U.S., Puerto Rico, and Mexico, with proportional representation among diverse populations most vulnerable to COVID-19 distributed across race/ethnicity, age, and those living with co-morbidities.

Participants in the study will randomly be assigned to receive SARS-CoV-2 rS with Matrix-M1 adjuvant or placebo. Each participant in the study will receive a total of 2 intramuscular injections over the course of the study.

Clinical Trial NCT04583995A Phase 3, Randomised, Observer-Blinded, Placebo-Controlled Trial to Evaluate the Efficacy and Safety of a SARS-CoV-2 Recombinant Spike Protein Nanoparticle Vaccine (SARS-CoV-2 rS) With Matrix-M1™ Adjuvant in Adult Participants 18-84 Years of Age in the United Kingdom -- Last Update Post November 17, 2020

This Phase 3 study is to evaluate the efficacy, immune response, and safety of a coronavirus disease 2019 (COVID-19) vaccine called SARS-CoV-2 rS with Matrix-M1 adjuvant in adults aged 18-84 years in the United Kingdom.

Approximately 15,000 participants will take part in the study. The first 400 participants who meet additional criteria will receive a flu vaccine, in addition to the SARS-CoV-2 rS vaccine or placebo, as part of a sub-study.

An effort will be made to enroll a target of at least 25% of participants who are ≥ 65 years of age, as well as prioritizing other groups that are most affected by COVID-19, including racial and ethnic minorities.

The trial protocol calls for unblinding of data once 152 participants have achieved mild, moderate, or severe endpoints. Two interim analyses are planned once 66 and 110 endpoints have occurred.

Clinical Trial NCT04533399: A Phase 2A/B, Randomized, Observer-blinded, Placebo-controlled Study to Evaluate the Efficacy, Immunogenicity, and Safety of a SARS-CoV-2 Recombinant Spike Protein Nanoparticle Vaccine (SARS-CoV-2 rS) With Matrix-M1™ Adjuvant in South African Adult Subjects Living Without HIV; and Safety and Immunogenicity in Adults Living With HIV -- Last Update Posted: November 2, 2020

This Phase 2 study is to evaluate the effectiveness and safety of a coronavirus disease 2019 vaccine called SARS-CoV-2 rS with Matrix-M1 adjuvant in a minimum of approximately 2,960 to a maximum of approximately 4,164 healthy HIV-negative (HIV-) adult participants and in approximately 240 medically stable HIV-positive (HIV+) adult participants in up to 15 sites across South Africa.

Clinical Trial NCT04368988: A 2-Part, Phase 1/2, Randomized, Observer-Blinded Study To Evaluate The Safety And Immunogenicity Of A SARS-CoV-2 Recombinant Spike Protein Nanoparticle Vaccine (SARS-CoV-2 rS) With Or Without MATRIX-M™ Adjuvant In Healthy Subjects—last Update Posted: October 9, 2020.

The Phase 1 portion is a randomized, observer-blinded, placebo-controlled trial designed to evaluate the immunogenicity and safety of NVX‑CoV2373, both adjuvanted with Matrix‑M and unadjuvanted. The trial enrolls approximately 130 healthy participants 18 to 59 years of age at two sites in Australia. The protocol’s two-dose trial regimen assesses two dose sizes (5 and 25 micrograms) with Matrix‑M and without.

The Phase 2 portion is expected to be conducted in multiple countries, including the United States, and would assess immunity, safety, and COVID‑19 disease reduction in a broader age range. The estimated completion date: July 2020.

The Phase 2b clinical trial of NVX-CoV2373 will include two cohorts. One cohort will evaluate the efficacy, safety, and immunogenicity in approximately 2,665 healthy adults. The second cohort will evaluate safety and immunogenicity in approximately 240 medically stable, HIV-positive adults. This allows for the evaluation of the vaccine across a diverse, representative study population.