Introduction:
Influenza vaccination is the most effective approach to reducing the risk of influenza exposure, particularly for the elderly. It protects against severe influenza illness, hospitalization, and major adverse cardiovascular events. For individuals at high risk, such as the elderly, the use of adjuvanted vaccines has been shown to provide additional benefits over standard influenza vaccines. Specifically, adding an adjuvant to the influenza vaccine has improved the immune response and effectiveness against influenza-related primary care visits and hospitalizations. This article will explore the advantages of adjuvanted influenza vaccines and their role in protecting high-risk individuals against influenza.
What Is Flu?
Influenza and flu are the same thing. Flu is a commonly used term for influenza, an acute respiratory illness caused by a virus. It can cause various symptoms, including fever, chills, cough, runny nose, sore throat, headache, muscle aches, extreme weakness, and fatigue. Although typically lasting between two to seven days, the illness can persist for longer periods, especially in older adults and individuals with chronic diseases. This viral illness can prolong recovery due to persistent cough and fatigue. In severe cases, pneumonia and hospitalization may be required, and influenza can even be fatal, particularly in older individuals.
Influenza is highly contagious and can spread through respiratory droplets produced by infected individuals when coughing or sneezing. It can also be contracted by contacting surfaces contaminated with the virus, such as toys, unwashed utensils, and unwashed hands. Anyone, regardless of age, can contract influenza.
What Is an Adjuvanted Flu Vaccine?
An adjuvanted flu vaccine is a type of influenza vaccine that includes an adjuvant, which is a substance that enhances the body's immune response to the vaccine. Adjuvants are typically added to vaccines to improve their effectiveness, especially in individuals who may have a weaker immune system, such as older adults or people with certain underlying medical conditions.
What Does Adjuvant Mean in a Vaccine?
In the context of vaccines, an adjuvant is a substance that is added to a vaccine to enhance the body's immune response to the vaccine. Vaccines stimulate the immune system to recognize and fight off specific infectious agents, such as viruses or bacteria. However, in some cases, the immune response generated by a vaccine may not be strong enough to provide adequate protection against the targeted infection.
Adjuvants are designed to address this issue by boosting the immune response to the vaccine. They can do this by several mechanisms, such as activating certain immune cells, enhancing the production of antibodies, or prolonging the immune response. By improving the immune response to the vaccine, adjuvants can help to increase the efficacy and durability of protection provided by the vaccine.
There are several different types of adjuvants that can be used in vaccines, including mineral salts, oil-in-water emulsions, and liposomes. Adjuvanted vaccines are widely used for a variety of infectious diseases, including influenza, hepatitis B, and human papillomavirus (HPV). The use of adjuvants in vaccines is carefully regulated by regulatory agencies to ensure their safety and efficacy.
What Is Adjuvanted Trivalent Flu Vaccine?
Adjuvanted trivalent vaccine is designed to protect against three different strains of the influenza virus, including two influenza A viruses and one influenza B virus. This influenza vaccine is specifically recommended for individuals aged 65 years and older. This vaccine contains an adjuvant that is intended to enhance the immune response to the vaccine, which is especially important in older adults who may not respond as effectively to the vaccine as younger individuals.
Adjuvanted trivalent vaccines generate a stronger immune response in older individuals compared to other influenza vaccines that lack an adjuvant. This increased immune response suggests that adjuvanted trivalent flu vaccines may be more effective than non-adjuvanted vaccines, although this has not been conclusively demonstrated. It typically takes approximately two weeks following immunization to develop protection against influenza, which may last up to one year. Although individuals who receive the vaccine can still contract influenza, the symptoms are typically milder. However, the vaccine will not protect against colds or other respiratory illnesses that are sometimes mistaken for influenza but are caused by different viruses.
Contraindications of Adjuvanted Trivalent Flu Vaccine:
The administration of adjuvanted trivalent flu vaccines is not recommended for the following individuals:
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People under the age of 65 years.
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Individuals who have previously had a severe allergic reaction (anaphylaxis) to the vaccine or any of its components, except for eggs.
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People who developed Guillain-Barré Syndrome (GBS) within six weeks of a prior influenza vaccination.
Moreover, this vaccine should be temporarily postponed for individuals with severe acute illnesses, with or without fever, who should generally wait until they feel better before receiving the vaccine. However, those with a minor illness, such as a cold, can still receive the vaccine.
Advantages of Adjuvanted Vaccines Compared to Standard Vaccines:
Recent studies indicate that adjuvanted vaccines offer a slight advantage in effectiveness for individuals aged 65 years and older as compared to standard influenza vaccines. Research suggests that adjuvanted influenza vaccines have the potential to decrease hospitalizations due to respiratory-related illnesses and lower the need for primary care consultations related to influenza, as compared to standard vaccines.
When Should Adjuvanted Flu Vaccine Be Given?
To prevent influenza as effectively as possible, individuals are advised to receive the vaccine prior to the onset of the influenza season, ideally in October or early November. A single dose is recommended. Since the influenza virus mutates frequently and immunity against it may not last for more than a year, it is crucial to receive the influenza vaccine annually to safeguard against the virus strains that might be prevalent that year.
Can Adjuvanted Flu Vaccines and Other Vaccines Be Given Concurrently?
Adjuvanted flu vaccines can be administered concurrently with other vaccines or at any time before or after other vaccines. However, it is essential to assess individuals aged 65 and above for pneumococcal vaccination eligibility, as they are eligible for it as well. If an adjuvanted flu vaccine and other vaccines are given through injection simultaneously, separate limbs should be used, or they can be injected into the same muscle but separated by at least 2.5 cm (1 inch). For each vaccine administered through injection, a distinct administration set (needle and syringe) must be used.
How Safe Is Adjuvanted Flu Vaccine?
While most people who receive the vaccine experience no side effects or only mild reactions, such as soreness, redness, or swelling at the injection site, adjuvanted influenza vaccines may produce more injection site reactions than non-adjuvanted vaccines, but they are generally mild and resolve within a few days. Severe allergic reactions to the vaccine are rare, and if they do occur, it is usually within a few minutes to a few hours after receiving the vaccine, requiring immediate medical attention.
However, individuals should seek medical attention promptly if they experience any of the following symptoms within three days of vaccination: hives, swelling of the mouth and throat, difficulty breathing, hoarseness or wheezing, high fever (over 40 degree Celsius or 104 degree Farenheit), convulsions or seizures, or any other severe reaction to the vaccine.
Conclusion:
To conclude, it is a must for all elderly individuals to take an adjuvanted flu vaccine to prevent themselves from influenza and its complications. Adjuvanted flu vaccines do provide some additional benefits over non-adjuvanted or standard vaccines. Therefore, elderly individuals should take its benefits and the recommended dose at the appropriate time.
