Frequently Asked Questions

Rabies is an old viral disease of mammals, maintained in animals, most often transmitted to humans through the bite of a rabid animal. Exposures can also occur through scratches, abrasions, open wounds, or mucous membranes (such as a person’s eyes, nose or mouth) contaminated with saliva or other potentially infectious material from a rabid animal. Both nonbite and bite exposures require treatment with rabies post-exposure prophylaxis.¹

Infection with the rabies virus is not curable but it is preventable. Rabies is prevented through vaccinating household pets, avoiding contact with stray animals and wildlife, and seeking prompt medical care if exposed. The Advisory Committee on Immunization Practices (ACIP) advises that prompt rabies post-exposure prophylaxis is essentially 100% effective in preventing human rabies.² After the onset of the clinical symptoms of rabies, death is inevitable.²

Once the rabies virus enters the body, it hijacks cells, sequesters the body’s immune response, and penetrates the muscles.³  The rabies virus replicates in neurons and reaches and spreads throughout the central nervous system, causing either furious rabies or paralytic rabies. ³ After infecting the central nervous system, the rabies virus spreads through peripheral nerves to the salivary glands and other tissues.⁴ The virus damages and may kill neurons, resulting in brain dysfunction that ultimately leads to death.⁵

More than 90% of all rabid animals reported in the United States are wildlife (not domestic animals, which include pets and livestock). The 5 species of wild animals that are considered the primary reservoirs, which means they are more prevalently rabid and have a higher risk for transmitting the virus, are⁶:

• raccoons
• bats
• skunks
• foxes
• mongooses (in Puerto Rico) 

Worldwide. Around the world, about 59,000 people die from canine rabies every year, which is 160 people a day.  The majority of these deaths occur in Africa and Asia and 40% are in children under the age of 15.^7,8

United States. In the United States, there are approximately 2 deaths from rabies every year.⁹ Bats are currently the most common source of human rabies infection (at a rate of 70%) as many people are often either unaware that bats can cause rabies or that they were even bitten.¹⁰ However, real-life studies tracking humans with suspected rabies exposures in US emergency departments found nearly 50% – 70% of post-exposure prophylaxis (PEP) is administered due to domestic dog exposures.^11,12

Canine rabies costs global economies an estimated $8.6 billion USD every year. The majority of these costs are a result of productivity lost to premature death, cost of post-exposure prophylaxis, and income lost while seeking post-exposure prophylaxis. The yearly costs for emergency response activities related to rabies in the United States is estimated to be about $7.6 million. The cost of post-exposure prophylaxis in the United States is estimated to be $209 million a year.^7,13

As a result of vaccination programs, canine rabies has been eliminated from the United States. However, dogs can still potentially acquire rabies from wildlife that are infected with the virus.¹³ Throughout the United States, rabies vaccination is required for dogs, and it is critical to maintain the current 70% vaccination rate in order to protect pets and humans from the rabies virus.¹³

PEP is a 3-step process that helps in preventing human rabies in exposed patients who have not been previously vaccinated against the virus (because the rabies virus is too powerful for the human immune system to fight).^14,15 A human rabies immune globulin (HRIG) is an important component of PEP.¹⁶ Administration of an HRIG prevents the rabies virus from advancing into the bite victim’s central nervous system long enough for the vaccine to boost the patient’s own natural immune response.² The combination of HRIG and rabies vaccine is critically important because not all patients will develop protective antibody titers by the end of the 14-day post-exposure regimen.¹⁷ Because the incubation period for rabies in a given person cannot be readily predicted, delivering antiviral antibodies with an HRIG, such as KEDRAB, as soon as possible after exposure is recommended. Delays in treatment are potentially lethal.^16,18

The 3 Crucial Steps in Post-exposure Prophylaxis

Yes. According to the ACIP, the 3-step post-exposure prophylaxis process (wound washing, human rabies immune globulin, rabies vaccine) is essentially 100% effective. A human rabies immune globulin (HRIG) is an important component of PEP. A rabies vaccine can take approximately 7 to 10 days to work and may not be enough to prevent a rabies infection from becoming fatal.¹⁵

No, unless the vaccine isn’t available and/or wasn’t administered the same day, in which case it would need to be given the following day. Post-exposure prophylaxis in persons who have not previously received the rabies vaccine should always include administration of both the passive antibody (human rabies immune globulin) and the vaccine (human diploid cell vaccine [HDCV] or purified chick embryo cell vaccine [PCECV]).² 

HRIG provides immediate protection. It is administered only once, and to previously unvaccinated patients, to provide rabies virus-neutralizing antibody coverage, known as passive immunization, until the patient responds to the rabies vaccine.^15,16

The rabies vaccine stimulates the patient’s immune system to produce virus-neutralizing antibodies for ongoing protection. This is known as active immunization and it occurs approximately 7 to 10 days after initiation of the vaccine series, which should be given according to the manufacturer’s instructions and at a site away from HRIG injection.^15,16

No. The dose for human rabies immune globulin is always 20 IU/kg body weight, regardless of when the patient receives PEP treatment. Human rabies immune globulin, such as KEDRAB, and the first dose of rabies vaccine should be given as soon as possible after exposure, preferably at the time of the first rabies vaccine dose. However, should a delay occur, administer KEDRAB at any time up to and including 7 days after the first dose of rabies vaccine. If there is a delay, initiate post-exposure prophylaxis at any time after exposure.¹⁶

When performed appropriately, post-exposure prophylaxis is essentially 100% effective in preventing human rabies. However, failures have occurred when a rabies vaccine series was not administered or a human rabies immune globulin (HRIG) was not properly administered. These include not administering HRIG; only injecting HRIG intramuscularly when bite site(s) are known; not injecting HRIG into all bite wounds; and less than thorough infiltration of HRIG at the exposure site(s).^2,15,19,20

Each year in the United States, an estimated 60,000 people are treated for a potential exposure to the rabies virus.¹⁰

Typically, after exposure to a rabid or potentially rabid animal, human rabies immune globulin should be administered to persons who have not previously been vaccinated for the rabies virus. There are certain instances where previously vaccinated persons without adequate antibody titers should receive HRIG.²

Yes, children are one of the highest at-risk age groups for rabies exposure. This is because children are more likely to approach potentially rabid animals, are smaller in size, and are less able to defend themselves during an animal attack.²¹ Globally, 40% of those who are bitten by animals suspected of being infected with the rabies virus are children under the age of 15.⁵

The first and only FDA-approved HRIG with established safety and effectiveness in adults and children is KEDRAB.¹⁶

The amount of volume needed will depend on each patient’s bite scenario, wounds, and body weight. Since pediatric patients usually weigh less than adults, the need for dilution may be likely to increase during HRIG administration. Without dilution, a higher concentration HRIG product may not have enough volume to ensure adequate coverage for the treatment of large or multiple bites or scratches. When administering HRIG to any patient, it’s important to follow Advisory Committee on Immunization Practices (ACIP) guidelines.¹⁴

KEDRAB is a human rabies immune globulin (HRIG) indicated for passive, transient post-exposure prophylaxis (PEP) of rabies infection to persons of all ages when given immediately after contact with a rabid or possibly rabid animal. KEDRAB should be administered concurrently with a full course of rabies vaccine.¹⁶ KEDRAB is a biologic prepared by chromatographic fractionation from a pool of plasma collected from selected US adult human donors who have been immunized with rabies vaccine and have developed high titers of anti-rabies antibody.²²

The recommended dosage of KEDRAB for pediatric and adult patients is 20 IU/kg body weight. No more than the recommended dose of KEDRAB should be given, even if the antibody response to vaccination is delayed.¹⁶

KEDRAB is prepared from the plasma of healthy, US adult donors who have been immunized with the rabies vaccine and have developed high titers of anti-rabies antibodies in their blood. Donors and donated plasma are carefully screened to help reduce the risk for transmission of viral disease. Some of the purification process steps for KEDRAB, such as euglobulin precipitation and ion exchange chromatography, are also known to contribute to virus removal.²²

KEDRAB is for wound infiltration and intramuscular use. When the bite site is known and infiltration at the bite site is feasible, as much of the dose as possible should be infiltrated into and around any detectable bite wounds. Any remaining volume should be injected intramuscularly at an anatomical site distant from the site of rabies vaccination administration.¹⁶

No, not necessarily. It’s critical to ensure that all wounds are fully infiltrated with human rabies immune globulin, regardless of concentration. Without dilution, a higher concentration HRIG may not have enough volume available to ensure adequate coverage for the treatment of large or multiple bites and/or scratches, especially in patients with lower body weight, such as children.^15,16

KEDRAB is the first and only FDA-approved HRIG that has been studied for safety and effectiveness in children.¹⁶

Additionally, KEDRAB comes in 2-mL and 10-mL vials which are visibly different in size, making it easy for hospital staff to identify the dosage needed. KEDRAB is available in the 150 IU/mL concentration, which has been in use for many years and is already familiar to healthcare professionals.¹⁶

Lastly, KEDRAB is available in a ready-to-use solution; dilution with dextrose is not necessary. This may lower the potential for errors caused by the need to prepare an admixture.^16,23

KEDRAB has been available in the US since 2017.²² 

Outside of the US, KEDRAB has been sold and marketed since 2006 as KamRAB^®. More than 5 million mLs of the product has been sold globally.²²

Yes, KEDRAB administration is necessary. No, the vaccine alone isn’t enough. A human rabies immune globulin (HRIG), such as KEDRAB, is an important component of post-exposure prophylaxis (PEP). It provides immediate rabies virus-neutralizing antibody coverage, known as passive immunization, until the patient responds to the rabies vaccine series. The rabies vaccine can take approximately 7 to 10 days to work and may not be enough to prevent a rabies infection from becoming fatal. The rabies vaccine series stimulates the immune system to produce virus-neutralizing antibodies for ongoing protection.^15,16

Per Advisory Committee for Immunization Practices (ACIP) recommendations, administration of an HRIG prevents the rabies virus from advancing into the bite victim’s central nervous system long enough for the vaccine to boost the patient’s own natural immune response.^2,15

Additionally, PEP failure can occur when HRIG is not administered correctly.¹⁹

Using a higher volume of an HRIG does not increase chances of compartment syndrome.²⁴

No cases of compartment syndrome were detected in studies measuring the feasibility of RIG wound infiltration in small compartments when performed by experienced healthcare staff following proper post-exposure prophylaxis protocol.²⁴