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 est ...

candidate developed by the

University of Queensland , mottoeng = By means of knowledge and hard work , established = , endowment = A$224.3 million , budget = A$2.1 billion , type = Public research university , chancellor = Peter Varghese , vice_chancellor = Deborah Terry , city = ...

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 Adjuvant therapy, also known ...

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 v ...

. 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 phase ...

, after a number of trial participants were found to give

false positive A false positive is an error in binary classification in which a test result incorrectly indicates the presence of a condition (such as a disease when the disease is not present), while a false negative is the opposite error, where the test resul ...

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 immun ...

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 diagn ...

tests for affected participants. Nine days prior to the termination, on 2 December, the first

emergency use authorisation An Emergency Use Authorization (EUA) in the United States is an authorization granted to the Food and Drug Administration (FDA) under sections of the Federal Food, Drug, and Cosmetic Act as added to and amended by various Acts of Congress, inclu ...

had been granted to a COVID-19 vaccine; the

Pfizer–BioNTech COVID-19 vaccine The Pfizer–BioNTech COVID-19 vaccine (INN: tozinameran), sold under the brand name Comirnaty, is an mRNA-based COVID-19 vaccine developed by the German biotechnology company BioNTech. For its development, BioNTech collaborated with Americ ...

in the United Kingdom. Following the termination of V451, vaccine production capacity by CSL Limited was diverted to the

Oxford–AstraZeneca COVID-19 vaccine The Oxford–AstraZeneca COVID19 vaccine, sold under the brand names Covishield and Vaxzevria among others, is a viral vector vaccine for prevention of COVID-19. Developed in the United Kingdom by Oxford University and British-Swedish com ...

References

External links

* {{COVID-19 pandemic Australian COVID-19 vaccines Clinical trials Pharmaceutical industry in Australia Protein subunit vaccines