Vaccination Flashcards
Passive Immunity
- Passive immunity is acquired by obtaining antibodies from a person with active immunity to the disease.
- Protection is immediate but duration is shorter as it can last a few weeks + repeated doses may be needed.
- Antiserums are antibodies from animals and Immunoglobulins are antibodies from humans
Active Immunity
Active immunity is acquired from having had a disease, or from receiving a vaccination.
Vaccines contain either a live attenuated (disabled) form of a virus or bacteria (e.g. MMR 56 and BCG), an inactivated virus (e.g. flu jab), detoxified toxins (e.g. tetanus), or extracts from the microbe (e.g. hep B).
Live attenuated vaccines produce
a durable immunity, although not necessarily as durable as having had the disease.
- Additionally, some immunocompromised patients and pregnant women should avoid live vaccines.
Inactivated vaccines last
from months to years + may require boosters.
- Patients allergic to eggs may also be allergic to some flu jabs.
- HIV+ patients should not receive TB vaccine (BCG vaccine).
Some inactivated vaccines are adsorbed onto
an adjuvant e.g. aluminium hydroxide to enhance antibody response
Assuming the vaccination schedule has been followed travellers do not require any immunisation for travel to
the US, Europe, Australia or New Zealand.
- For other areas vaccination may be required: polio, TB, yellow fever, meningitis, hepatitis A, hepatitis B (also indicated for healthcare workers), rabies, tetanus, typhoid and cholera. It is also important to advise travellers on food hygiene.
Vaccinations
Cautions
- Vaccination may be postponed if the patient is suffering from an acute illness e.g. fever or systemic upset. However, if the patient is suffering from other minor illnesses (NOT fever or systemic upset), then the immunisation does not need to be postponed.
• Impaired immune response and drugs affecting immune response:
Immune response to vaccines may be reduced in immunosuppressed patients and there is also a risk of infection with a live vaccine. The live vaccine should be postponed until at least 3 months after stopping high-dose systemic corticosteroid and at least 6 months after stopping other immunosuppressive drugs or generalised radiotherapy.
• Predisposition to neurological problems:
If personal or family history of febrile convulsions, there is a higher risk of this occurring during fever from any cause including immunisation, but it’s NOT contraindicated to immunisation. - It is recommended for children who have had fever WITHOUT neurological deterioration to have the vaccine.
- For children with an evolving neurological disorder(s), the immunisation should be deferred, and the child should be referred to a specialist. If the cause of the neurological disorder is NOT identified, then the immunisation should be deferred until stable
NOTE: Paracetamol is recommended for
the prophylaxis of post-immunisation pyrexia following immunisation with Men B vaccine
Allergy and cross-sensitivity
Vaccines are contra-indicated in patients with confirmed anaphylactic reaction to a vaccination dose in the past, which contained the same antigens or vaccine component e.g. anti-bacterial in viral vaccines.
Pregnancy +
Live vaccines
Live vaccines should not routinely be given to pregnant women due to the risk of foetal infection. However, if there is a HIGH risk of exposure to disease, the need for vaccine outweighs the risks to foetus.
BF +
Live vaccines
Although there is a risk of the live vaccine being present in breast-milk, vaccination is not contra-indicated for women who are breast-feeding when there is a HIGH risk of exposure to disease.
Directions for administration
- If alcohol or disinfectant is used to clean the skin, it should be allowed to evaporate before vaccination to prevent the vaccine from being inactivated.
- When 2 or more vaccines are required, they can be administered before or after each other preferably into different limbs. If more than one injection is given in the same limb, administer at least 2.5cm apart.
- Vaccine should not be administered intravenously! Most vaccines are given by IM route, but some can be given intradermal, deep subcutaneous or oral route. Patients with bleeding disorders (e.g. haemophilia or thrombocytopenia) should be administered the vaccine via deep subcutaneous route instead of IM.
- The DoH advise against the use of jet guns for vaccinations, due to the risk of transmitting blood borne infections such as HIV.
- Vaccine which are liquid suspension or reconstituted before use, should be adequately mixed to ensure uniformity.
Handling and storage
Refrigerated vaccines should be stored between 2-8oC and not allowed to freeze. Also, protect from light.
Opened multidose vials and reconstituted vaccines, should be used within the recommended period.
Measles, mumps and rubella vaccine
Important safety information
No evidence has been found to link the MMR vaccine with bowel disease or autism. The chief medical officers have advised that the MMR vaccine is the most effective and safest to protect children against measles, mumps and rubella.
Idiopathic thrombocytopenic purpura (ITP)
ITP is a disorder that can lead to easy or excessive bruising + bleeding. The bleeding results from unusually low levels of platelets. It can affect both adults + children. ITP has rarely occurred following MMR vaccine. Risk of ITP after MMR vaccine is much less than risk of infection with mild measles + rubella virus.
