Yellow Fever Vaccine - Types, Indication, Contraindications, and Side Effects.

Introduction:

Yellow fever is a viral infection spread by a mosquito. It is a zoonotic disease, especially in monkeys. When transmitted to humans, it can cause liver damage and damage to internal organs. The virus spreads through the bite of infected mosquitos; people cannot spread yellow fever among themselves through casual contact. Vaccination has been the most critical measure to prevent yellow fever. There are several vaccination strategies used to avoid yellow fever disease and transmission. Infant immunization and mass immunization campaigns are designed to increase the coverage in countries at risk and vaccination for travelers going to endemic areas.

Who Discovered the Yellow Fever Vaccine?

Max Theiler discovered the yellow fever vaccine in 1937. He was awarded the Nobel Prize in 1951 for developing a vaccine against yellow fever.

What Is the Yellow Fever Vaccine?

The 17D-204 YF is a freeze-dried, live-attenuated, and highly effective vaccine. It is available in single-dose and multi-dose vials. The vaccine should be stored at 2 to 8 degrees. It is reconstructed with normal saline and given after 1 hour of reconstruction. In addition, 0.5 mL of vaccine is given subcutaneously. Revaccination is recommended every ten years for people at risk of yellow fever exposure.

What Are the Recommendations for the Yellow Fever Vaccine?

On average, a single yellow fever vaccine provides long-lasting protection, and most do not need a booster dose. In addition, the yellow fever vaccine is affordable, safe, and provides effective immunity within one week. Although the yellow fever vaccine is like other vaccines, it may not fully protect everyone.

The yellow fever vaccine is recommended for:

• The people who are nine months or older than nine months.

• The people who are traveling or are residents of high-risk areas.

• People over 60 should be given the vaccine after a careful risk-benefit assessment.

• People traveling or planning to stay where yellow fever is at high risk, like in South America and Africa, will need to be vaccinated. The booster dose is recommended after every ten years.

• The people studying yellow fever in the lab should also get vaccinated to protect themself and family from yellow fever.

What Are the Reactions to the Yellow Fever Vaccine?

The reactions to the yellow fever vaccine are generally mild that include the following:

• Muscle ache.

• Fever.

• Pain or swelling on the injection site.

• Headache.

• Body ache.

• Vomiting.

• Diarrhea.

But sometimes, people have severe life-threatening reactions, which include:

• The anaphylactic shock includes difficulty in breathing and swallowing.

• Encephalitis or meningitis includes swelling of the brain, spinal cord, and surrounding tissues.

• Guillain-Barre Syndrome is an uncommon sickness of the nervous system in which the person's immune system damages the nerve cells, causing muscle weakness or paralysis.

• Internal organ failure or dysfunction.

• Unusually weak or tired.

• Mental confusion, trouble in speaking or understanding.

• Seizures.

• Trouble walking.

Report to your doctor immediately after you have any above reactions to vaccination.

How Should You Use Medication?

The yellow fever vaccine is given subcutaneously by the healthcare professional in the hospital or clinic. A copy of the vaccination information sheets will be given before vaccination; read the given sheet carefully. The vaccine is contraindicated in infants below nine months of age.

Where Should You Store Your Medication?

The drug should not be stored at home as given in a hospital or clinic by the healthcare provider.

Who Should Not Get the Yellow Fever Vaccine?

The vaccine is not recommended for people who are:

• Six months or younger.

• Organ transplant recipients.

• Any active infection with fever.

• People with malignant conditions.

• People who are allergic to vaccines or allergic to any vaccine component.

• Immunocompromised patients.

• People on immunotherapy.

• Patients undergoing radiation therapy.

• People have symptoms of the human immunodeficiency virus (HIV).

• Bleeding disorders.

• People diagnosed with thymus disorder or abnormal immune function.

• Autoimmune disease.

• Vision or hearing changes.

Does the Yellow Fever Vaccination Have Any Effects on Pregnancy?

The yellow fever vaccine has been given to many pregnant women without any potential side effects on the fetus. But the yellow fever vaccine is a live vaccine and poses a theoretical risk. Therefore, pregnant women should avoid traveling to places with a risk of yellow fever. However, the yellow fever vaccination should be discussed with the doctor if travel is unavoidable.

What Are the Strategies to Control Yellow Fever?

There are different strategies to control yellow fever, which include:

• Vaccination - As yellow fever vaccination is the most important measure to prevent yellow fever. Yellow fever vaccination is available worldwide, and certain countries like Africa and South America require certificates documenting yellow fever vaccination.

• Control Strategies for Mosquitos - The risk of yellow fever can be reduced by checking on breeding sites and spraying insecticides where they develop. During the epidemic, spraying insecticides can be used to kill mosquitoes, along with emergency vaccination campaigns.

• Rapid Response and Detection During an Outbreak - For controlling outbreaks, early detection of yellow fever and rapid response through emergency vaccination campaigns are essential. One single case of yellow fever in an unvaccinated population should be considered an outbreak. Every case should be adequately investigated, especially in areas where most of the population has been vaccinated. The investigation teams must assess and respond to the outbreak with emergency measures and long-term immunization plans.

Conclusion:

The yellow fever outbreak is transmitted to a susceptible population by mosquito bites. Hence, vaccination is the most effective way of preventing yellow fever.