helpful websites:  NIH Vaccines    Immunisation   Immunisation Guidelines for Ireland 2008 Edition, Royal College of Physicians of Ireland (good summary of all of the vaccine schedules) GAVI: the vaccine alliance   International Society of Travel Medicine (find travel clinicls worldwide)  Yellow Fever Vaccination Clinics (if you are travelling to where yellow fever is endemic –CDC).  CDC Travel Advisory. 

Coalition for Epidemic Preparedness Innovations (CEPI)

 List of Vaccines approved by the FDA  Vaccine Schedule (birth-6 year old)  Vaccine Schedule 7-18

Companies: Bavarian Nordic. VaxArt (oral vaccines)

Vaccines are a solution or suspension of materials used to induce artificial active immunity by stimulating the immune system with an antigen that will prevent the disease. Vacines expose the body to a disabled form of a pathogen (or harmless pieces of it), but the immune system reacts as it would to a true assault, generating protective membory cells in the process. Antigens may be organisms, toxoids (modified toxin, rendered nontoxic), part of organisms (capsules) and nucleic acids. The ideal vaccine is one that is specific, safe, long lasting, no side effects, stable, easy to produce and easy to administer. The types of vaccines include toxoids which are immunogenic but not toxic, macromolecules from pathogens and recombinant vectors. For example, one can take genes which code for surface antigens for say hepatitis B and transfect yeast cells which will produce those antigens. Recombinant virus vacines are safe in that there is no problem with reversion. As a disadvantage, the immune repertoire is directed against only a small part of virus protein. 

Vaccination has virtually eradicated diseases such as polio, tetanus, tuberculosis, chicken pox, measles, hepatitis, etc. The approach using vaccinations has exploited the ability of the immune system to prevent infectious diseases. Vaccination with non-live materials such as proteins generally leads to an antibody response or CD4+ helper T cells response (Raychaudhuri and Morrow (1993), Immunology Today 14). On the other hand, vaccination with live materials such as live cells or infectious viruses generally leads to a CD8+ cytotoxic T lymphyoctye response. A CTL response is crucial for protection against cancers, infectious viruses and certain bacteria. This poses a practical problem in that the only way to acheive a CTL response is to use live agents which are themselves patholgenic. The problem has been dealth with by using an inactivated microorganism or one that is dead. Killed vaccines are easy to produce and safer. However, killed virus vaccines do not induce cellular immunity and have low levels of humoral immunity. They also require frequent boosting. A second approach is to use an  attenuated microorganism which is alive and immunogenic but not disease producing. Attenuation refers to the production of strains of pathogenic microorganisms which have essentially lost their disease producing ability. One way to accomplish this is to subject the microorganism to unusual growth conditions and/or frequent passage in cell culture. Mutants are then selected which have lost virulence but yet are capable of eliciting an immune reponse. Live-attenuated virus vacines replicate in vivo and induce cellular and humoral immunity. Disadvantages include risk of reversion to virulence. They are also expensive to transport in that they are heat/light sensitive.

Vaccines are often formulated to contain various adjuvants in addition to antigen. Adjuvants aid in attaining a more durable and higher level of immunity using smaller amounts of antigen or fewer doses than if the antigen were adminsitered alone. 

Recommended Vaccination Schedule

Vaccination and number of injections should be given at the following ages: (See National Immunisation Offce, February 2011 “”Frequently asked questions for Healthcare Professionals in Relation to Vaccine Scheduling for Children” ) see Royal C

2 months: (6 in 1 = Diptheheria, Tetanus acellular Pertussis (whooping cough), inactivted polio, Haemophilus Influenze B, Heapatis B) + Pneyococcal Conjugate Vacine (PCV)),

4 months (6 in 1 + Meningococcal C vaccine (Men C))

6 months: 6 in 1 + PCV + Men C . 3 injections.  Give 6 in 1 and Men C in the same limb (different sites and 2.5 cms apart) and give PCV in the other limb

2 months: Measals, Mumps Rubella (MMR) + PCV .  2 injections

13 months: Men C + Haemophilus Influenzae B (Hib) 

Passive Immunization

Injection of purified antibody or antibody-containing serum for rapid, temporary protection or treatment of an individual is called passive immunization. Newborns receive natural passive immunity from maternal immunoglobulin that has crossed the placenta or is present in the mother’s milk. Passive immnization with monoclonal antibdies has several advantages over active vaccination. For one, it allows treating people which poorly respond to vaccines, such as the elderly, young children or immune compromised individuals. In addition, it is the treatmnet of choice in situations where rapid protection is crucial, such as for post exposure treatment or prophylaxis for the acutely exposed.

Human serum globulin is prepared from pooled plasma and contains the normal repertoire of antibodies for an adult. It is preferable to animal immunoglobulin because there is less risk of a hypersensitivity reaction (serum sickness).

Types of Vaccines

Recombinant Protein Vaccines: 

RNA Vaccines: (injecting RNA into body)

–SARS:  no vaccine to this vrius

–Polio: several vaccines. The US uses inactivated vaccine (e.g., polio -injectable version) and other countires use an attentuated vaccine (e.g., measles mumps rubella).

–Influenza:  One is intramuscular and another nasal form.

DNA Vaccines:  a genetically engineered plasmid contianing a DNA sequence that encodes viral protein(s) introduced into body. 

–West Nile Virus Vaccine:  only veterinary use

Universal Vaccines:

One challenge to vaccine development is constructing vaccines that both incorproate and attack multiple virus strains.

Longhorn Vaccines and Diagnostics has patented a composite peptide approach that enables vaccines to string epitopes together into unique peptides. They find conserved epitopes in each target, put them in an optimal order and attach T cell epitopes to simulate the immune system further. (kaumaya PT “Peptide Vacines incorporating a “promiscuous” T-cell epitope bypass certain haplotype restricted immune reposnes and provide broad spectrum immunogenicity” J. Mol. Recognit. 6(2) 1993). 

 Vectors used to Get Vaccines into the Cell

Adenovirus Vector Vaccines: