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HSV-2 Vaccine

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Herpes simplex virus-2 (HSV-2) is the leading cause of genital herpes, a sexually transmitted disease affecting over 500 million people worldwide. BlueWillow’s intranasal nanoemulsion (NE) vaccine is uniquely suited to offer protection against this painful and distressing affliction, through its ability to elicit both a systemic and mucosal immune response.

About HSV-2

Genital herpes is a sexually transmitted disease most commonly caused by the herpes simplex virus-2 (HSV-2). Infections are lifelong and often asymptomatic facilitating the spread of the disease amongst sexual partners and from mother to child during birth. Genital herpes is also associated with an increased risk of HIV acquisition. The disease is widespread in both developed and underdeveloped countries, and is a global health priority. An estimated one out of six people of ages 15 to 49 in the U.S. are infected with HSV-2. The virus causes painful recurring genital sores that result in considerable psychological distress in patients.

Current Vaccines

Currently there are no approved vaccines for HSV-2.

Our Science

BlueWillow’s nanoemulsion (NE) adjuvant is uniquely suited to enable vaccines for sexually transmitted infections, wherein pathogens enter the body across mucosal surfaces. When used with intranasal vaccination, the NE adjuvant elicits both mucosal and systemic immunity. The mucosal immunity elicited by NE vaccines provides critical protection against these infections at their port of entry.

Recent research conducted by the University of Cincinnati in conjunction with BlueWillow has demonstrated that an intranasal NE vaccine elicits protection in both the prophylactic & therapeutic guinea pig models for HSV-2. This represents the first vaccine to show efficacy in both models.

As demonstrated in the chart below, BlueWillow’s intranasal NE HSV-2 vaccine elicits complete protection against genital herpes lesion recurrence in naïve guinea pigs following challenge. In addition the vaccine prevented the establishment of viral latency in 11 of the 12 animals vaccinated.


In the therapeutic guinea pig model, the same intranasal NE vaccine formulation reduced genital herpes lesion recurrence and viral shedding by more than 50%, as shown in the following chart.


Intranasal administration of BlueWillow’s novel NE adjuvant offers unique advantages over earlier intramuscular vaccine candidates, given its ability to elicit both a systemic and a mucosal immune response. Based on the results in animals, BlueWillow is planning to advance both its prophylactic and therapeutic NE vaccine candidates into P1 human studies.

Partnering Information

In July 2013, BlueWillow Biologics entered into an agreement with the Division of Microbiology and Infectious Diseases (DMID), a division of NIAID. Under the agreement, DMID agreed to fund certain activities and studies in support of developing intranasal and intramuscular NE vaccines for HSV-2. In addition, in March 2017, NIH awarded BlueWillow a $1.5M SBIR Phase II grant to complete its remaining preclinical activities and to hold a pre-IND meeting with the FDA for its intranasal vaccine candidate.  Activities under the grant are currently ongoing.

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