Vaccine Theory | International Nurse

What is a vaccine and how does it work:

A vaccine contains a dead or weakened form of an antigen which stimulates the immune system to produce specific antibodies

If infection in the future occurs the immune system is able to fight of and protect against the antigen.

Types of vaccines:

Live vaccine: using an attenuated (weakened) form of a virus or bacteria. Live vaccines do not usually cause disease in recipients who have already healthy immune systems however may cause a mild version of the infection. Live vaccines are not safe for anyone immunocompromised as can cause serious infection due to uncontrolled replication of the virus.

Dead or inactivated vaccine: using bacteria and viruses which have been inactivated. After immunisation the vaccine antigens cannot replicate or cause disease. This type of vaccine can be safely given to a person who is immunocompromised however may not develop the same amount of protection compared to an otherwise healthy person. Most inactivated vaccines usually require multiple doses.

Subunit vaccines: using parts of a bacteria or virus antigen or bacterial toxins that have been made harmless.

Immunise on time, every time:

For best protection against serious diseases everyone needs to be immunised on time, evert time. Studies have shown that if all recommended doses of vaccine are given, they will protect 80% to 98% of children who are immunised. A very small number of children who are immunised do not develop strong immunity and may still become ill with one of the diseases, however the illness is usually milder than those who are not immunised at all.

Community/ heard immunity:

Community immunity is an important part of protecting the community against disease. People who are immunised do not usually get sick from the illness and cannot transmit the disease to others. This prevents infection from circulating the community and protects people who are not immunised such as those too young and those immunocompromised. Approximately 95% of people in a community must be immunised to achieve community immunity.

Vaccine Safety:

Vaccines must be trialled extensively before it can be approved for community use. Before a vaccine is approved for use in New Zealand the safety and effectiveness must be demonstrated to the satisfaction of Medsafe.

Mild reactions from vaccinations are common and occur due to the immune systems natural response. Serious reactions are rare although there is always a possibility – anyone who receives a vaccination Is monitored for at least 20 minutes after to ensure medical treatment is readily available and to ensure safety.

Mild reactions include:

- Mild fever

- Unsettled (tiredness and crying for up to 48 hours)

- Swelling or pain at injection site

Serious Reactions:

- Febrile convulsion (risk can be reduced by keeping child comfortable and cool if they have a fever and administering paracetamol).

Immunisation Schedule:

Pregnancy:

- TDaP injection (boostrix): tetanus, diphtheria and pertussis. all pregnant women should get a Tdap immunisation in the third trimester to protect from complications of pertussis.

- Influenza injection: highly effective in preventing influenza and its complications during pregnancy and for up to six months after birth.

6 weeks:

- RV1 oral vaccine (Rotarix): Rotavirus. live vaccination, for safety reasons the first dose of Rotarix can only be given to babies younger than 15 weeks and the second can only be given to babies younger than 25 weeks.

- DTaP-IPV-Hep B/Hib injection (Infanrix hexa): diphtheria, tetanus, pertussis, polio, hepatitis B and haemophilus influenzae. Requires three doses at 6 weeks, 3 months and 5 months to be fully effective and induce long-lived immunity. Should not be given to any child who has experienced neurological problems, occurring within 7 days following previous vaccination containing pertussis.

- PCV10 injection (Synflorix): pneumococcal disease. Protects against pneumococcal disease caused by at least 10 types of streptococcus pneumoniae. Administered at 6 weeks, 3 months and 5 months and booster dose at 15 months. Healthy children who miss immunisations can catch up at any time until their 5th birthday.

3 months:

5 months:

15 months:

- Hib injection (Hiberix): Haemophilus influenzae type B. The 4th dose of Hib immunisation. - MMR injection (Priorix): Measles, Mumps and Rubella. Protects against the 3 highly contagious viral infections, live vaccination. In outbreak/ high risk areas babies over 6 months are able to be vaccinated. The first dose is 95% effective, the second boosting the effectiveness therefore requiring two vaccinations at 15 months and 4 years. - PCV10 injection (Synflorix): pneumococcal disease. Protects against pneumococcal disease caused by at least 10 types of streptococcus pneumoniae. Administered at 6 weeks, 3 months and 5 months and booster dose at 15 months. Healthy children who miss immunisations can catch up at any time until their 5th birthday.

- Varicella injection (varilrix): chickenpox. A live vaccination containing varicella-zoster virus, children under 13 years only require a single dose of vaccine which will protect approx. 8 in 10 children. children and adults aged 13 years and older require two doses for protection.

4 years:

- DTaP-IPV injection (infanrix IPV): diphtheria, tetanus, pertussis and polio. Given as a booster vaccine at 4 years.

- MMR injection (Priorix): Measles, Mumps and Rubella. Protects against the 3 highly contagious viral infections, live vaccination. In outbreak/ high risk areas babies over 6 months are able to be vaccinated. The first dose is 95% effective, the second boosting the effectiveness therefore requiring two vaccinations at

15 months and 4 years. 11+12 years:

- TDaP injection (boostrix): tetanus, diphtheria and pertussis. Booster vaccination also given during pregnancy.

- HPV injection (Gardasil 9): human papillomaviruses (HPVs). Covers 9 types of the virus. 2 doses are required, 6 months apart. Funded for all aged 9 years to 27 years. 45 years:

- Td injection (ADT Booster): tetanus and diphtheria.

65 years

- Td injection (ADT Booster): tetanus and diphtheria.

- Influenza injection (annually from age 65).