Vaccine Info

RVx201 Herpes Vaccine

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Last reviewed
October 7, 2021
Fact checked by
Robert Carlson, MD

RVx201 Herpes Vaccine Description

RVx201 is a first-in-human herpes simplex virus type 2 (HSV-2) live-attenuated therapeutic vaccine modified to be interferon sensitive and destroy the ability of the virus to inhibit immune responses.

Produced by Rational Vaccines, Inc., technology is based on the pioneering research of the late Dr. William Halford, who dedicated over 25 years to studying herpes simplex virus 1 (HSV-1) and herpes simplex virus 2 (HSV-2).

Rational's HSV vaccine candidates carry attenuating mutations in a key viral gene that encodes a protein named “infected cell protein 0” (ICP0). ICP0 controls the balance of HSV latency and replication. These mutations are designed to weaken the virus, limiting its ability to cause infection while retaining its ability to sufficiently stimulate the body’s immune system to elicit an effective and amplified response to combat infection. Unfortunately, ICP0 also aids the virus in evading the immune system’s protective defenses, namely the interferon-mediated response.

Research studies with the predecessor mutant of RVx-201 (termed in research publications HSV-2 0∆NLS) have provided the following observations: Mice vaccinated with HSV-2 0∆NLS showed an improved antibody response compared to vaccination with a subunit vaccine candidate, Mice immunized with HSV-2 0∆NLS were protected in subsequent challenges with live wild-type virus, Studies in mice demonstrated the predecessor HSV-2 mutant to be avirulent, and providing supportive evidence of its potential safety.

The UK issued the Innovation Passport for RVx201 in July 2021. The Innovation Passport is awarded by the UK's Innovative Licensing and Access Pathway (ILAP) Steering Group, consisting of the Medicines and Healthcare products Regulatory Agency (MHRA), National Institute for Health and Care Excellence, and the Scottish Medicines Consortium. RVx201 is the first vaccine for HSV-2 to be awarded this designation under ILAP, which the MHRA launched in January 2021

Rational Vaccines, Inc. is located at 8 Cabot Rd #3800, Woburn, MA.

RVx201 Herpes Vaccine Indication

RVx201 Herpes Vaccine candidate is indicated to destroy the ability of the herpes virus (HSV-2) to inhibit immune responses. Symptomatic herpectic disease is a condition of immuno-tolerance. 

'Our theory is that by introducing a live-attenuated mutant of the herpes virus, which can safely replicate and infect new cells at the site of injection, our candidate may elicit a wide enough immune response to act as an immune modulator. Our hope is that this immunotherapy could help patients better control the symptoms caused by the reactivation of their wild-type herpetic infection,' says Rational Vaccines's website.

RVx201 Herpes Vaccine News

September 15, 2021 - Rational Vaccines announced Kerstin Westritschnig, M.D., as the Company's chief medical officer. Specialized in clinical immunology, Dr. Westritschnig brings extensive industry experience, including deep expertise in vaccine research and development, infectious disease, immune-oncology, and biologics.

July 22, 2021 - Rational Vaccines Receives UK MHRA Innovation Passport for RVx201 for the Treatment of Genital Herpes Resulting From Herpes Simplex Type 2 Virus. The United Kingdom’s new Innovative Licensing and Access Pathway (ILAP) was launched by the U.K Medicines and Healthcare products Regulatory Agency in January 2021 to reduce the time to market innovative medicines.

March 30, 2021 - Study validates pre-clinical safety of novel live-attenuated HSV-2 vaccine candidates.

RVx201 Herpes Vaccine Clinical Trials

In preclinical animal models, data have shown that RVx201 is safe and does not establish latency, and the vaccine's immunization protects against lethal challenges with virulent HSV-2 strains. RVx201 is in the IND enabling stage of development. The purpose of this stage is to secure approval to conduct first-in-human clinical trials.

Clinical Trials

No clinical trials found