V451 was a
COVID-19 vaccine
A COVID19 vaccine is a vaccine intended to provide acquired immunity against severe acute respiratory syndrome coronavirus 2 (SARS‑CoV‑2), the virus that causes coronavirus disease 2019 ( COVID19).
Prior to the COVID19 pandemic, an e ...
candidate developed by the
University of Queensland and the Australian pharmaceutical company
CSL Limited
CSL Limited is an Australian multinational specialty biotechnology company that researches, develops, manufactures, and markets products to treat and prevent serious human medical conditions. CSL's product areas include blood plasma derivative ...
. The vaccine candidate used the University of Queensland's
molecular clamp technology and the
MF59 MF59 is an immunologic adjuvant that uses squalene. It is Novartis' proprietary adjuvant that is added to influenza vaccines to help stimulate the human body's immune response through production of CD4 memory cells.
MF59 is the first oil-in-water ...
adjuvant In pharmacology, an adjuvant is a drug or other substance, or a combination of substances, that is used to increase the efficacy or potency of certain drugs. Specifically, the term can refer to:
* Adjuvant therapy in cancer management
* Analgesic ...
.
Description
V451 is a protein
subunit vaccine
A subunit vaccine is a vaccine that contains purified parts of the pathogen that are antigenic, or necessary to elicit a protective immune response.
A "subunit" vaccine doesn't contain the whole pathogen, unlike live attenuated or inactivated va ...
. As part of the vaccine's design, researchers added "a fragment of one protein found on the HIV virus" as a "ground-breaking
molecular clamp technology".
Terminated trial
The development of the vaccine was cancelled on 11 December 2020 during its
Phase I trial
The phases of clinical research are the stages in which scientists conduct experiments with a health intervention to obtain sufficient evidence for a process considered effective as a medical treatment. For drug development, the clinical phases ...
, after a number of trial participants were found to give
false positive test results for
HIV antibodies
The human immunodeficiency viruses (HIV) are two species of ''Lentivirus'' (a subgroup of retrovirus) that infect humans. Over time, they cause acquired immunodeficiency syndrome (AIDS), a condition in which progressive failure of the immune ...
when they did not in fact have HIV. This was due to the HIV virus fragment used as a molecular clamp leading to "a partial antibody response" to HIV. This is an undesirable outcome as it will interfere with future
HIV screening
HIV tests are used to detect the presence of the human immunodeficiency virus (HIV), the virus that causes acquired immunodeficiency syndrome (AIDS), in serum, saliva, or urine. Such tests may detect antibodies, antigens, or RNA.
AIDS diagnos ...
tests for affected participants.
Nine days prior to the termination, on 2 December, the first
emergency use authorisation had been granted to a COVID-19 vaccine; the
Pfizer–BioNTech COVID-19 vaccine in the United Kingdom. Following the termination of V451, vaccine production capacity by CSL Limited was diverted to the
Oxford–AstraZeneca COVID-19 vaccine.
References
External links
*
{{COVID-19 pandemic
Australian COVID-19 vaccines
Clinical trials
Pharmaceutical industry in Australia
Protein subunit vaccines