Stamaril1000 IU/0.5 ml

Approved / Established Use

Stamaril is indicated for active immunization against yellow fever infection in individuals aged 9 months and older who:

• Live in or are traveling to countries or areas in sub-Saharan Africa or tropical South America where yellow fever infection is endemic or where there is a risk of transmission.
• Require documented proof of vaccination for entry into certain countries under the International Health Regulations (IHR), even when travel is not to a high-risk area.
• Work with or may be exposed to the yellow fever virus (e.g., certain laboratory personnel), based on individual risk assessment.

Guideline-Supported Use in Special Situations

In outbreak settings, national and WHO guidance may extend use of Stamaril to infants as young as 6 months when the risk of yellow fever exposure is high and outweighs the risk of vaccine-associated adverse events in this younger age group.

Stamaril is not used to treat active yellow fever infection; it is a preventive (prophylactic) vaccine only, and it has no role once infection has occurred.

Each single-dose vial of Yellow Fever Vaccine contains live attenuated yellow fever virus (17D strain), propagated in embryonated chicken eggs and supplied as a lyophilized (freeze-dried) pellet or powder for reconstitution with the accompanying sterile diluent immediately before use.

The reconstituted 0.5 mL dose contains not less than the minimum potency required by the relevant national/international regulatory standard, along with stabilizing excipients (such as sorbitol and gelatin) and trace residual proteins from the egg-based manufacturing process.

Stamaril is a live attenuated viral vaccine containing a weakened (attenuated) strain of the yellow fever virus. It is used to actively immunize individuals against yellow fever, a mosquito-borne viral hemorrhagic illness found in parts of sub-Saharan Africa and tropical South America.

Stamaril is administered as a single subcutaneous injection at an approved or certified yellow fever vaccination center, so that the vaccination can be validly recorded on an International Certificate of Vaccination or Prophylaxis (ICVP) for travel purposes where required.

Stamaril belongs to the class of Vaccines, specifically Live Attenuated Viral (Travel/Endemic-Disease) Vaccines.

Yellow Fever Vaccine contains a live, attenuated (weakened) 17D-strain yellow fever virus. After subcutaneous injection, the attenuated virus replicates to a limited extent at the injection site and in regional tissues without causing the disease in immunocompetent individuals.

This limited replication exposes the immune system to yellow fever viral antigens, stimulating both humoral immunity (neutralizing antibody production) and cell-mediated immunity. Protective neutralizing antibodies typically develop within 10 days in the great majority of vaccinees, and current WHO guidance recognizes a single dose of Yellow Fever Vaccine as providing long-lasting, likely lifelong, protective immunity in most people.

Stamaril must be reconstituted immediately before use (see Reconstitution) and administered only by subcutaneous injection, typically into the outer aspect of the upper arm (deltoid region). It must not be given intravenously or intramuscularly.

Stamaril should only be administered by trained healthcare personnel at a designated/certified yellow fever vaccination center, so that the vaccination can be properly recorded on an International Certificate of Vaccination or Prophylaxis. Standard precautions for vaccine administration, including monitoring for immediate hypersensitivity reactions for at least 15–30 minutes after injection, should be followed, with epinephrine and other anaphylaxis management measures readily available.

• Other live vaccines: Stamaril can generally be given at the same visit as other live virus vaccines (e.g., MMR). If not given simultaneously, live vaccines are usually spaced at least 4 weeks apart, as closely spaced live-vaccine doses may reduce the immune response to one or both vaccines.
• Immunosuppressive therapy (corticosteroids, chemotherapy, biologic agents): Concurrent immunosuppressive treatment can blunt the immune response to Stamaril and, because it is a live vaccine, increases the risk of disseminated infection from the vaccine strain; vaccination is generally deferred until immunosuppression has resolved (see Contraindications and Precautions and Warnings).
• Antimalarial drugs (e.g., chloroquine): Chloroquine and related antimalarials may theoretically reduce the antibody response if started before or given concurrently with Stamaril; when possible, Stamaril should be given before starting antimalarial chemoprophylaxis.
• Blood products / immune globulin: Administration of blood products or immune globulin around the time of Stamaril may interfere with the immune response; spacing per standard immunization guidance is advised.

Most people who receive Stamaril experience only mild, self-limited reactions, including:

• Soreness, redness, or swelling at the injection site
• Low-grade fever
• Headache
• Muscle aches (myalgia) and general malaise

These common effects typically begin within a few days of vaccination and resolve within a week or so without specific treatment.

Rare but serious adverse events, including immediate hypersensitivity/anaphylaxis and the vaccine-associated viscerotropic and neurotropic syndromes, can occur; these are discussed in detail under Precautions and Warnings.

Pregnancy: Stamaril is a live vaccine, and live vaccines are generally avoided during pregnancy as a precaution. Stamaril should be given during pregnancy only if travel to a high-risk endemic area cannot be avoided or postponed and the potential benefit of protection is judged to outweigh the theoretical risk to the fetus; use only if clearly needed and after consulting a physician. If vaccination during pregnancy cannot be avoided, some guidelines suggest considering revaccination after delivery, per physician assessment.

Breastfeeding: There have been rare case reports of transmission of the vaccine virus through breast milk causing vaccine-associated neurotropic disease in exclusively breastfed infants, particularly those under 1 month of age. Stamaril should be avoided during breastfeeding unless travel to a high-risk endemic area is unavoidable; a physician should be consulted to weigh the risks and benefits, and temporary suspension of breastfeeding may be considered in some circumstances.

Vaccine-Associated Viscerotropic Disease (YEL-AVD)

A rare but serious adverse event in which the vaccine virus disseminates and causes a syndrome resembling severe wild-type yellow fever infection, with multi-organ involvement; it can be fatal in a substantial proportion of cases. Risk is higher in first-time vaccinees, particularly those aged 60 years and older.

Vaccine-Associated Neurotropic Disease (YEL-AND)

A rare adverse event involving the nervous system (e.g., meningoencephalitis, or, less commonly, a Guillain-Barré type syndrome), occurring more often in infants younger than 6 months (in whom Stamaril is contraindicated) and in older adults receiving their first dose.

Age-Related Risk

Because the risk of both YEL-AVD and YEL-AND is increased in first-time vaccinees aged 60 years and older, an individualized risk-benefit assessment is recommended before giving Stamaril to older adults, particularly when travel is elective or non-essential rather than to a high-risk endemic area.

Hypersensitivity

Because Stamaril is produced in eggs, individuals with a history of egg allergy should be evaluated carefully before vaccination; medical personnel and treatment for anaphylaxis should be immediately available whenever Stamaril is administered.

Certified Administration Requirement

In many jurisdictions, Stamaril must be administered at a designated or certified yellow fever vaccination center for the dose to be validly recorded on an International Certificate of Vaccination or Prophylaxis (ICVP) for travel documentation.

Deferral for Acute Illness

Vaccination with Stamaril should generally be postponed in individuals with moderate to severe acute febrile illness until the illness has resolved.

Stamaril is administered as a single measured dose by a trained healthcare professional, so overdose is unlikely in routine practice. There is no established specific antidote for excess exposure to the vaccine virus.

If an excessive dose is inadvertently administered, or if severe or unusual symptoms develop after vaccination, seek immediate medical attention or contact emergency services; the person should be monitored closely for signs of hypersensitivity reactions or other serious adverse events, with supportive care provided as needed by medical personnel.

Store the lyophilized (freeze-dried) vaccine refrigerated at 2°C to 8°C (36°F to 46°F), protected from light; do not freeze the diluent. Once reconstituted, use immediately; if immediate use is not possible, keep the reconstituted vaccine refrigerated at 2°C to 8°C, protected from light, and discard any unused portion after the time specified by the manufacturer (typically within 1 hour of reconstitution). Keep out of reach of children.

• Older adults (age 60 and above): Increased risk of serious adverse events (YEL-AVD, YEL-AND) with first-time vaccination; individualized risk-benefit assessment recommended, especially for non-essential travel (see Precautions and Warnings).
• Infants and children: Contraindicated under 6 months of age; generally not recommended between 6–8 months except during outbreaks with high exposure risk; routine use approved from 9 months of age (see Pediatric Uses).
• Immunocompromised individuals (including HIV infection): Stamaril is contraindicated in severe immunodeficiency; in asymptomatic HIV infection with preserved immune function, vaccination may be considered after individualized assessment by a physician (see Contraindications).
• Pregnant and breastfeeding women: See Pregnancy and Lactation for detailed guidance.
• Renal or hepatic impairment: No specific dose adjustment of Stamaril is established as required for renal or hepatic impairment; general precautions for vaccination in acutely ill patients still apply.

Stamaril is given as a single dose rather than a course of treatment. Protective antibody levels typically develop within about 10 days of vaccination in the great majority of recipients.

Current WHO position (reflected in amendments to the International Health Regulations) is that a single dose of Stamaril provides long-lasting, likely lifelong, protection for most people, and routine booster doses are not generally required. A physician may still recommend an additional dose in specific circumstances (e.g., prior vaccination during pregnancy, prior vaccination while significantly immunocompromised, or certain hematopoietic stem cell transplant recipients), based on individual assessment.

Stamaril is supplied as a lyophilized (freeze-dried) pellet or powder that must be reconstituted immediately before administration using only the sterile diluent supplied by the manufacturer for that specific product.

The diluent should be added to the vial of lyophilized vaccine and the vial gently swirled (not vigorously shaken) until the powder is fully dissolved, producing a clear to slightly opalescent, pinkish suspension. The reconstituted vaccine should be inspected visually for particulate matter or discoloration before use and must be used within the time specified by the manufacturer (commonly within 1 hour of reconstitution); any unused reconstituted vaccine remaining after this time must be discarded and not used for another patient.

Vaccines; Live Attenuated Viral Vaccines; Travel/Endemic-Disease Vaccines

Yellow Fever Vaccine works by introducing a live but attenuated (weakened) strain of the yellow fever virus (17D strain) into the body. This attenuated virus is capable of limited local replication but has lost the ability to cause significant disease in an immunocompetent host.

This controlled, low-level viral replication is sufficient to expose the immune system to yellow fever viral antigens, triggering the production of neutralizing antibodies and the development of cell-mediated immune memory. This immune response is what confers long-term protection against subsequent infection with wild-type yellow fever virus.

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Stamaril is approved for routine use in children from 9 months of age onward, using the same single 0.5 mL subcutaneous dose as in adults.

In outbreak settings where the risk of yellow fever exposure is judged to be high, national or WHO travel-medicine guidance may support use of Stamaril in infants as young as 6 months, after individualized risk assessment.

Stamaril is contraindicated in infants younger than 6 months of age because of a substantially increased risk of vaccine-associated neurotropic disease (YEL-AND) in this age group; safety and efficacy in this youngest age group have not been established as acceptable, and vaccination should not be given.