Usage
- Yellow fever vaccine is prescribed for the prevention of yellow fever, a viral hemorrhagic fever transmitted by infected mosquitoes. It is recommended for individuals 9 months and older traveling to or living in areas with a risk of yellow fever virus transmission in Africa and South America. It is also administered to laboratory workers who handle the virus.
- Pharmacological classification: Vaccine (Live, attenuated viral vaccine)
Alternate Names
- Yellow jack
- Yellow plague
- Bronze john
- YF-Vax (brand name)
- Stamaril (brand name)
How It Works
- Pharmacodynamics: The yellow fever vaccine contains a live, attenuated (weakened) strain of the yellow fever virus (17D strain). It stimulates an immune response, leading to the production of antibodies against the virus, thereby conferring long-lasting immunity (potentially lifelong for most individuals).
- Pharmacokinetics: The vaccine is administered subcutaneously (SC) or intramuscularly (IM). After injection, the attenuated virus replicates locally, stimulating the immune system. The exact metabolic and elimination pathways are not explicitly defined for vaccines.
Dosage
Standard Dosage
Adults:
- 0.5 mL single dose administered subcutaneously at least 10 days before potential exposure.
- A booster dose may be considered every 10 years for those at continued risk.
Children:
- 9 months and older: 0.5 mL single dose administered subcutaneously at least 10 days before potential exposure.
- 6-9 months: Only recommended during epidemics when the risk of infection is very high.
Special Cases:
- Elderly Patients: Same as adult dose, but requires careful consideration of contraindications and precautions due to potentially increased risk of adverse events.
- Patients with Renal Impairment: No specific dose adjustments are indicated.
- Patients with Hepatic Dysfunction: No specific dose adjustments are indicated.
- Patients with Comorbid Conditions: Patients with immunosuppression (including HIV, malignancies, or those on immunosuppressive therapy) should generally not receive the vaccine or should be carefully evaluated on a case-by-case basis.
Clinical Use Cases
The yellow fever vaccine is used for pre-travel prophylaxis or for residents in endemic areas, not for acute treatment of infections. Therefore, it is not typically used in settings like intubation, surgical procedures, mechanical ventilation, or the ICU.
Dosage Adjustments
Dose adjustments are based on age and individual risk factors, particularly immune status. (See special cases above).
Side Effects
Common Side Effects
- Mild reactions at the injection site (redness, pain, soreness)
- Mild fever
- Headache
- Myalgia (muscle aches)
Rare but Serious Side Effects
- Yellow fever vaccine-associated viscerotropic disease (YEL-AVD)
- Yellow fever vaccine-associated neurotropic disease (YEL-AND)
- Severe allergic reactions
Long-Term Effects
Generally, a single dose provides long-lasting protection.
Adverse Drug Reactions (ADR)
- YEL-AVD: A serious, multi-organ system failure that can be fatal.
- YEL-AND: A serious neurological illness that can be fatal.
Contraindications
- Hypersensitivity to any vaccine component (including eggs or chicken protein).
- Severe immunosuppression (e.g., from HIV/AIDS, leukemia, lymphoma, or immunosuppressive drugs).
- Moderate or severe acute illness (vaccination should be postponed).
- History of thymus dysfunction (including myasthenia gravis and thymoma) or thymectomy.
- Children under 6 months of age.
Drug Interactions
- Immunosuppressants (e.g., corticosteroids, methotrexate, biologic agents): May decrease vaccine effectiveness and increase the risk of infection.
- Live attenuated vaccines: Should generally not be administered within a specific timeframe of the yellow fever vaccine. Consult specific guidelines for intervals.
Pregnancy and Breastfeeding
- Pregnancy: The vaccine is generally contraindicated in pregnancy due to theoretical risks to the fetus, however, it may be administered if the risk of contracting yellow fever is substantial.
- Breastfeeding: The vaccine virus can be transmitted through breast milk. Avoid or postpone vaccination unless there is a significant risk of yellow fever infection.
Drug Profile Summary
- Mechanism of Action: Live attenuated virus vaccine stimulates the production of antibodies against the yellow fever virus, providing long-lasting immunity.
- Side Effects: Commonly mild injection site reactions, fever, headache, myalgia. Rarely, serious YEL-AVD or YEL-AND.
- Contraindications: Severe immunosuppression, hypersensitivity to vaccine components, age <6 months, certain medical conditions.
- Drug Interactions: Immunosuppressants, other live vaccines.
- Pregnancy & Breastfeeding: Generally avoided unless risk of yellow fever infection is significant.
- Dosage: 0.5 mL SC, single dose.
- Monitoring Parameters: Observe for signs of adverse reactions.
Popular Combinations
Not applicable.
Precautions
- Pre-screening for contraindications is essential.
- Vaccination at approved yellow fever centers.
FAQs (Frequently Asked Questions)
Q1: What is the recommended dosage for Yellow fever virus vaccine?
A: The standard dose is 0.5 mL administered subcutaneously.
Q2: Who should receive the yellow fever vaccine?
A: Individuals 9 months and older traveling to or residing in areas at risk of yellow fever transmission, and laboratory workers handling the virus.
Q3: What are the most common side effects of the vaccine?
A: Mild injection site reactions, fever, headache, and muscle aches.
Q4: Are there any serious side effects?
A: Rarely, YEL-AVD or YEL-AND can occur. These conditions require immediate medical attention.
Q5: Can pregnant women receive the vaccine?
A: Generally avoided unless the risk of yellow fever is high.
Q6: Can breastfeeding women receive the vaccine?
A: Generally avoided unless the risk of yellow fever is high, as the vaccine virus can be transmitted through breast milk.
Q7: How long does the protection from the vaccine last?
A: A single dose can provide lifelong protection for most people.
Q8: What should I do if I experience side effects after vaccination?
A: Contact your healthcare provider. Mild reactions are common. For severe or unusual symptoms, seek immediate medical attention.
Q9: Can the yellow fever vaccine be given with other vaccines?
A: Consult specific guidelines for recommendations on co-administration with other vaccines. Some live vaccines should not be given concurrently or within a specific timeframe.
Q10: Where can I get the yellow fever vaccine?
A: It must be administered at approved yellow fever vaccination centers.
