Verorab Rabies Vaccine

1. Introduction to Verorab Rabies Vaccine

Verorab is a purified, inactivated rabies vaccine derived from Vero cell cultures. Developed using advanced virological techniques, it ensures high immunogenicity and a strong safety profile. As a cell culture–based rabies vaccine, it eliminates the risks associated with older nerve tissue–derived vaccines.

Manufactured by Sanofi, Verorab is globally distributed and widely used in public health systems, private clinics, and travel medicine programs. It is listed as an essential medicine by the World Health Organization (WHO), underlining its critical role in the prevention and control of rabies in both endemic and non-endemic regions.

Its primary indications include:

• Pre-exposure prophylaxis for individuals at risk of rabies due to occupation or travel
• Post-exposure prophylaxis following bites or scratches by animals suspected of rabies

WHO endorses Verorab for use in rabies immunization programs as part of both intramuscular and intradermal schedules, especially in regions with limited access to healthcare.

2. Medical and Preventive Uses of Verorab

2.1 Approved Uses

Verorab is approved for two major clinical scenarios:

• Pre-exposure prophylaxis (PrEP): Recommended for veterinarians, animal handlers, laboratory workers handling rabies virus, and travelers to high-risk areas. It ensures protection prior to any potential rabies exposure.
• Post-exposure prophylaxis (PEP): Indicated following potential rabies exposure, including:
  • Animal bites or scratches
  • Mucosal contamination from infected saliva
  • Open wounds exposed to potentially rabid animals

2.2 Off-Label Uses and Investigational Applications

In some cases, Verorab may be used outside standard labeling:

• Administration to immunocompromised patients with altered dosing or scheduling
• Use in patients with interrupted or incomplete vaccination series
• Emergency mass vaccination programs in areas facing rabies outbreaks or natural disasters disrupting healthcare access

3. Mechanism of Action: How Verorab Works

Verorab introduces purified inactivated rabies virus antigen, specifically targeting the rabies glycoprotein G, which is essential for virus entry into host cells.

• The immune system responds by producing virus-neutralizing antibodies
• These antibodies prevent the virus from reaching the central nervous system
• Protective levels are typically reached within 7–14 days post-vaccination

In PEP cases, Verorab is administered alongside Rabies Immune Globulin (RIG) to provide immediate passive immunity while active immunization builds over time.

4. Verorab Composition and Formulation

• Active Ingredient: Inactivated rabies virus (Wistar strain PV-BHK21)
• Production method: Grown in Vero cell cultures, then purified and inactivated using β-propiolactone
• Excipients: Includes buffer solutions, stabilizers, and trace antibiotics (e.g., neomycin)
• Presentation: Lyophilized powder in a glass vial with a separate vial of diluent

Each reconstituted dose delivers a minimum of 2.5 IU of rabies antigen, suitable for both intramuscular and intradermal administration.

5. Dosage and Administration Guidelines

5.1 Pre-Exposure Prophylaxis Protocols

The standard intramuscular regimen consists of three doses:

• Day 0, Day 7, and Day 21 or 28

Intradermal protocols are also endorsed by WHO and may involve lower antigen doses, especially in resource-limited settings. Booster doses are advised every 3–5 years for continuous-risk individuals, or after potential exposure if antibody titers are low.

5.2 Post-Exposure Prophylaxis (PEP) Protocol

Two main IM schedules are recommended:

• Essen protocol: 5 doses on Days 0, 3, 7, 14, and 28
• Zagreb protocol: 2 doses on Day 0 (both deltoids), followed by single doses on Days 7 and 21

RIG should be co-administered on Day 0 for category III exposures, infiltrated around the wound and injected intramuscularly elsewhere if needed.

5.3 Catch-Up Dosing and Incomplete Schedule Management

If doses are delayed or skipped:

• Continue remaining doses without restarting the entire series
• Consult serological testing if immunosuppression or uncertainty exists

6. Common and Serious Side Effects of Verorab

6.1 Common Adverse Reactions

• Injection site pain, redness, or induration
• Fever, headache, fatigue, or muscle aches
• Gastrointestinal discomfort in some cases

Most symptoms resolve within 1–2 days and do not require treatment.

6.2 Less Common but Serious Reactions

• Hypersensitivity reactions: rash, urticaria, or angioedema
• Anaphylactic shock (very rare)
• Neurological complications like Guillain-Barré syndrome (extremely rare)

All serious events must be reported to pharmacovigilance authorities promptly.

7. Warnings, Contraindications, and Precautions

7.1 General Warnings

• Verorab does not replace immediate and thorough wound cleansing
• Incomplete vaccination may result in inadequate immunity
• Immunosuppressive treatments can reduce vaccine effectiveness

7.2 Contraindications

• Known allergy to any component of the vaccine
• History of anaphylaxis after previous rabies vaccination

7.3 Important Precautions Before Use

• Review of past allergic reactions or immunodeficiencies
• Monitoring of patient for at least 30 minutes post-injection
• Appropriate resuscitation equipment should be accessible

8. Drug and Vaccine Interactions with Verorab

• Immunosuppressants (e.g., chemotherapy, biologics) may blunt antibody response
• High-dose corticosteroids can delay seroconversion
• Concurrent administration with other vaccines is permitted but should be injected at separate sites

Inactivated vaccines like Verorab generally do not interfere with other vaccines but spacing is recommended when possible.

9. Handling, Storage, and Disposal Guidelines

9.1 Proper Storage Conditions

Verorab must be stored under strict cold chain conditions to maintain its immunogenic potency. The vaccine should be kept refrigerated at a controlled temperature between 2°C and 8°C at all times. Freezing must be strictly avoided, as it can irreversibly denature the vaccine’s active components and render it ineffective.

Each vial should be inspected regularly for any signs of discoloration or particulate matter. Healthcare facilities should implement a rotation system, ensuring that older stock is used first and that expiration dates are routinely checked. Products should be discarded if the expiration date is exceeded or if there is evidence of improper storage.

9.2 Reconstitution and Handling Instructions

Verorab is supplied as a lyophilized powder that must be reconstituted using the sterile diluent provided with each vial. The following steps are critical to ensure correct preparation:

• Draw the entire contents of the diluent vial into a sterile syringe.
• Inject the diluent into the vial containing the freeze-dried vaccine powder.
• Gently swirl the vial to mix; avoid vigorous shaking.
• Use the reconstituted vaccine within 30 minutes to avoid loss of potency.

All needles and syringes must be handled with care to prevent accidental injury or contamination. Single-use devices should never be reused. After administration, used sharps must be immediately placed in puncture-proof sharps containers in accordance with biomedical waste management protocols.

9.3 Disposal of Expired or Unused Vaccine

Expired or unused vaccine vials should be disposed of as per national medical waste disposal guidelines. These typically include:

• Labeling and segregating biological waste separately from general waste
• Autoclaving or incinerating expired vials in approved medical waste facilities
• Documenting the batch number, quantity, and reason for disposal for regulatory compliance

Proper disposal prevents environmental contamination and accidental use of compromised vaccine material.

10. Overdose and Emergency Management

Overdose with Verorab is uncommon, but may occur due to incorrect administration or repeated dosing outside of the recommended schedule. Instances may include administration of an extra dose or re-administration of a full course due to uncertainty in exposure history.

Symptoms following overdose are generally mild and include localized pain, swelling, or systemic symptoms like fever or fatigue. Severe outcomes are rare due to the vaccine’s high safety profile.

In such cases:

• Symptomatic treatment should be initiated
• The patient should be observed for adverse effects, especially hypersensitivity
• No specific antidote exists; management is supportive and primarily observational

11. Guidelines for Careful Administration in Special Populations

11.1 Use in Elderly Patients

In geriatric patients, immunosenescence may result in a reduced or delayed immune response. While Verorab remains safe and well-tolerated in the elderly, clinicians should monitor these patients more closely to assess vaccine efficacy and side effect profile.

Common concerns in this demographic include:

• Subtle adverse events that may be misattributed to underlying comorbidities
• Need for booster dose evaluation based on antibody titers

11.2 Use in Pregnant and Lactating Women

Verorab is considered safe for administration during pregnancy and lactation. WHO supports its use when the risk of rabies exposure outweighs potential risks to the mother or fetus. The vaccine does not contain live virus and therefore does not pose a teratogenic threat.

Key considerations include:

• Assessing the exposure risk in rabies-endemic regions
• Avoiding delay in PEP in pregnant women following exposure
• Compatibility with breastfeeding—no need to interrupt nursing

11.3 Use in Pediatric Populations

Verorab is approved for use in children, including infants. The dosage is the same as for adults, though administration technique may differ based on age.

Special precautions for children include:

• Using the anterolateral thigh for intramuscular injections in infants under 2 years
• Providing distraction or comfort measures during vaccination
• Monitoring for fever and local reactions, which may be more pronounced

12. Safe Handling Precautions for Healthcare Workers and Caregivers

Personnel involved in the storage, preparation, and administration of Verorab must adhere to strict biosafety and infection control protocols. The following precautions are essential:

• Use of personal protective equipment (PPE), including gloves and lab coats
• Hand hygiene before and after handling the vaccine
• Proper disposal of reconstitution equipment and syringes in sharps containers

In the event of accidental exposure (e.g., needlestick injury or splash to mucous membranes), the affected individual should:

• Immediately wash the area with soap and water or flush with saline
• Report the incident and seek medical evaluation
• Follow institutional protocols for post-exposure assessment

Stringent training and vigilance help prevent occupational exposure and ensure safe vaccine handling throughout the immunization process.

Verorab Rabies Vaccine FAQ