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Novavax Covid-19 Vaccine Trial

The Novavax vaccine candidate is called NVX-CoV2373. This vaccine candidate is engineered from the genetic sequence of SARS-CoV-2, the virus that causes Covid-19 disease.

The Novavax vaccine in the South African trial leverages the same technology used in an influenza (flu) vaccine that successfully completed a later stage clinical trial, Phase 3, in the US, as well as other experimental vaccines against Ebola and MERS.

Previously, NVX-CoV2373 was tested in over 130 volunteers in Australia. There are additional phase 2 studies, similar to this one active here in South Africa, ongoing in Australia and the U.S.

Trial sites

The trial has enrolled volunteers at 10 sites in Gauteng, the Western Cape, KwaZulu-Natal and the Free State.

  • In Gauteng, the sites are in Soweto (two sites), Hillbrow, and Shosanguve.
  • In the Western Cape, the sites are in Cape Town and Worcester.
  • The KwaZulu-Natal sites are in Veralam and Umlazi.
  • The Free State site is in Bloemfontein.


This Phase 2 NVX-CoV2373 study in South Africa will enroll up to 2,904 volunteers 18-64-years-old. The trial will evaluate the vaccine candidate’s safety, immunogenicity, and efficacy [protection against Covid-19].

The randomized, observer-blinded, placebo-controlled trial will include two groups, known as cohorts:

  • One cohort will evaluate the efficacy, safety and immunogenicity of NVX-CoV2373 in approximately 2,665 healthy, HIV-negative adults.
  • The second cohort will evaluate the safety and immunogenicity of NVX-CoV2373 in approximately 240 medically stable, HIV-positive adults.

Participants will need to provide written informed consent to participate in the trial and they will remain on the trial for approximately one year.

Trial implementation

The study gathers safety and immunogenicity data and, in addition, it is designed to evaluate efficacy against symptomatic COVID-19. It will also evaluate safety and immunogenicity in a small cohort of HIV exposed participants. This study will be conducted in South Africa under the regulatory oversight of South African Health Products Regulatory Authority in partnership with the Bill and Melinda Gates Foundation.

When you enrol in the study, a medical examination will be performed (health check, including blood pressure check) and blood and nasal swab samples will be collected.

Your participation includes receiving either NVX-CoV2373 or a placebo (half of the participants will receive the vaccine candidate; half will receive a normal placebo vaccine of saline)

  • You will receive 1 injection at the time of enrolment and 1 injection 3 weeks later of either the NVX-CoV2373 vaccine being studied or a placebo
  • You will attend a series of visits to the doctor’s office for evaluation and collection of samples to assess immune response
  • You will be provided a diary to track any symptoms and be followed closely for any signs of COVID-19 disease for the 12 months.
  • You will not be charged for study exams and procedures.
  • If you develop COVID-19 symptoms during the study, you should notify the clinical trial team. The team can help assess for COVID-19 disease and provide guidance.
  • We will also do repeat nasal or saliva samples on you, as well as blood samples, should you be identified to be infected with the virus during the study.


The NVX-CoV vaccine candidate is one of the lead experimental vaccines that are currently in the clinical development phase in humans. The South African study is part of a larger, global clinical programme to evaluate NVX-CoV2373, including larger Phase 3 studies with approximately 30,000 participants, to be launched throughout the world.

A special committee of experts was established to ensure safety of the vaccine throughout this study. This committee, the Data Safety Monitoring Board (DSMB), has the important job of reviewing all of the data as the study goes along (rather than waiting to the end) to make sure there is no undue risk to participants in this study. If the DSMB felt it was necessary, they could recommend to stop this study at any time due to safety concerns.

The protocol document is available for viewing here. A protocol is a document describing the background, rationale and objectives as well as the design, methodology, statistical considerations and organisation of a clinical research study.



Screening for Novavax COVID-19 vaccine trial participation is now closed.