Vaccines as Specific Antigens

SCENARIO 2 Vaccines as Specific Antigens The government is holding an HPV (Human Papilloma Virus) immunization program for girls aged at least 11 years. The HPV vaccine is an active immunization that aims to induce the body's immunity to prevent infection with certain diseases. The vaccine is given by being injected intramuscularly several times at certain intervals. The HPV vaccine is a type of recombinant vaccine. Know the mechanism of why immunization needs to be repeated (booster). LO 6 Tutor Instruction Questions: a. Why does a booster need to be given to immunization? For most vaccines used in the first year of life, 3-4 doses are given by 12 months of age. Conventionally, in human vaccination, the 'priming' dose is any given at less than 6 months of age and the 'booster' dose is given at 9-12 months of age. So, for example, the WHO standard schedule for a vaccine containing diphtheria‒tetanus‒pertussis (which was introduced in 1974 as part of the Expanded Program for Immunization84) consists of 3 initial doses at 6, 10 and 14 weeks of age without a booster. This schedule was chosen to provide early protection before maternal antibody levels decrease (maternal antibodies have a half-life of around 30-40 days85, so very little protection is provided to babies of mothers over 8-12 weeks of age) and because it is known that vaccine compliance is greater. best if doses are given close together. However, infant immunization schedules around the world vary widely—few high- or middle-income countries use the Expanded Immunization Schedule Program—and most were introduced with little consideration of how best to optimize immune responses. Indeed, schedules that begin later at 8‒12 weeks of age (when there is less interference from maternal antibodies) and have a longer gap between doses (8 weeks rather than 4 weeks) are more immunogenic. A large number of new vaccines have been introduced since 1974 as a result of extraordinary technological developments, but these have generally been adapted to existing schedules without taking into account optimal scheduling for these new products. The main schedule used globally for diphtheria‒tetanus‒pertussis vaccines, and changes to the UK immunization schedule since 1963. It is also worth noting that surveys show vaccines are rarely delivered on schedule in many countries and, as such, published schedules may not be how vaccines are actually delivered in the field. This is especially true in remote areas (for example, where health workers visit only occasionally) and areas with limited or chaotic health systems, leaving children vulnerable to infection.A booster dose is an additional dose of vaccine that is received after the patient receives the first dose. Booster injections provide the body with re-exposure to parts of the vaccine that protect the body from disease. Boosters can increase immunity against viruses or bacteria through a process called immunological memory. Immunological memory is the body's ability to recognize and respond to foreign antigens that have been previously exposed.For example, booster tetanus shots for adults in the United States are recommended every ten years. Studies have shown that after ten years after a tetanus shot, the body begins to forget how to fight tetanus. The booster dose alerts the immune system to attack the virus or bacteria. Know the various routes for administering vaccines. LO 7 Tutor Instruction Questions: a. What are the routes of vaccine administration? Each vaccine has a recommended route and site of administration. This information is included in the manufacturer's package insert for each vaccine. Deviation from the recommended route may reduce vaccine effectiveness or increase local reactions.Health workers must always perform hand hygiene before administering vaccines by any route. Occupational Safety and Health Administration (OSHA) regulations generally do not require that gloves be worn when administering vaccines unless the person administering the vaccine is likely to come into contact with potentially infectious bodily fluids or has open wounds on the hands.The vaccines available in the United States are administered by 4 routes: Oral Route (PO): Oral vaccines are given by dripping into the mouth. Rotavirus vaccines (RV1 [Rotarix], RV5 [RotaTeq]) are the only routinely recommended vaccines administered orally. Rotavirus vaccine should not be injected. Intranasal Route (NAS): The intranasal vaccine is administered into each nostril using a manufacturer-filled nasal sprayer. Live attenuated influenza vaccine (LAIV [FluMist]) is the only vaccine administered via the intranasal route. Subcutaneous Route (Subcut): Subcutaneous injections are given into the fatty tissue found below the dermis and above the muscle tissue. Intramuscular (IM) Route: Intramuscular injections are given into the muscle through the skin and subcutaneous tissue. Recommended injection locations based on age. Use the correct needle length based on the recipient's age, weight, and gender.When administering a vaccine by injection, select the correct needle size based on route, age, patient size, and injection technique. See the chart below to identify the route for each injectable vaccine.