Vaccines

What are vaccines? a substance used to stimulate the production of antibodies and provide immunity against one or several diseases, prepared from the causative agent of a disease, its products, or a synthetic substitute, treated to act as an antigen without inducing the disease. (WATCH How vaccines work you tube 1:58) North Carolina is an innovative leader in vaccine research, development and manufacturing Vaccines are one of the safest and most cost-effective tools in medicine despite the myths

History of vaccines Prevented millions of deaths and disabilities Small pox vaccine was introduced in Europe in the 1700’s Most u.s. children are vaccinated against 14 or more diseases

smallpox

Where are we at today? Vaccine researchers are making exciting progress in developing new and improved vaccines, manufacturing processes and delivery methods

Key terms Vaccination: is the introduction into the body of a weakened, killed or piece of disease-causing agent to prevent disease Immunization: is the process by which the body becomes immune to a disease. A person can become immune by getting the disease or from a vaccination Epidemic: is when more people in a particular population get a disease than typically expected

Key terms Pandemic: is when a disease outbreak is global or over large areas of the world (CDC is attempting to prevent this with Ebola) Pathogen: a disease-causing agent. It usually refers to a virus, bacteria, fungi or protozoan parasite Virus: a small, infectious agent that only can replicate inside the cells of a living organism. It has a core of dna or rna surrounded by a protein coat and is not itself a living cell

Key terms Bacteria: a large group of microorganisms. Antibodies: Special proteins produced by the body to attack foreign invaders such as pathogens Antigens: substances, usually proteins or polysaccharides(carbs), that cause the body to produce antibodies

Questions to ask yourself? Can you imagine eating a banana instead of getting a shot? Using flu vaccine antigens produced by tobacco plants? Ever heard of vaccine biodefense or nano-printing new vaccines? !!!!!!All this and more is taking place in north Carolina!

History of pandemics 1918-1919 – a severe outbreak of a virulent strain of influenza (flu) virus killed between 50- 100 million people worldwide. Known as “Spanish flu” 500,000 people died in the u.s. from the flu This flu killed a greater percentage of young healthy adults 2009 – a new strain of influenza emerged and had the same characteristics similar to the 1918 flu Think about how our world has changed since 1918, do these changes make a deadly disease scenario more or less likely?

Pandemics Smallpox, bubonic plague and HIV have caused deadly pandemics as well However, the flu viruses have rapidly changing strains and circulate among animals as well as people – more chance of causing a pandemic There have been several flu pandemics in the last 100 years, and the interconnected nature of our current global society only makes these more likely in the future!

Public health and pandemics Public health (cdc) work hard everyday to prepare for future pandemics and help prevent them One of their key weapons against disease is vaccination Vaccination’s main goal is to prevent disease

Vaccinations Scientists have developed vaccinations against many of the most threatening disease of the past: smallpox, polio, cholera, typhoid, yellow fever and influenza North Carolina requires vaccination against 10 different diseases by the time children start school The federal centers for diseases control and prevention (cdc) recommends 5 more to that 10 This not only protects the child, but protects the entire community “HERD IMMUNITY”

Polio and yellow fever

Vaccinations Lowering the incidence of the disease in the population, vaccinations protects even those who are too young to be vaccinated, those who have an allergy to the vaccine or those who have a weakened immune system However, not all diseases have vaccines at this time such as HIV, malaria and chlamydia

How vaccines work Your immune system protects you from diseases caused by a wide variety of pathogenic organisms, including viruses, bacteria, protozoans and worms This is done by a layered defense system: from mechanical barriers (such as skin and mucus) to specific attacks on invading organisms The purpose of the vaccine is to “jump-start” a specific immune response by introducing the person (or animal) being vaccinated There is enough of a specific, disease causing agent to cause an immune response but not enough to cause illness

How vaccines work ** The human immune system is able to recognize and distinguish between protein molecules that belong to its owner’s body (self) and those that come from outside attacker (foreign)

Types of vaccines Live by weakened “Attenuated” disease agents Inactivated or killed disease agents Subunit vaccines- subunit of disease Toxoid vaccines- toxin secreted by disease Conjugate vaccines- infants/young children Dna vaccines- experimental Recombinant vector vaccines- experimental

Live attenuated weakened disease agent Many vaccines are made from live attenuated weakened disease agent This includes live virus vaccines Even though viruses are not considered living organisms, functional virus particles are called “live” Examples: Flu Mist, the nasal flu vaccine, mmr, chickenpox Advantages: very effective in including full protection against their diseases

Problems with live viruses vaccine Can mutate to a more dangerous form Some people, especially those with weak immune systems (such as cancer or hiv patients) , get sick even from the weakened form of the disease BECAUSE THEIR IMMINE SYSTEMS ARE ALREADY WEAKENED OR “COMPRIMISED” To remain effective, a live vaccine usually needs constant refrigeration all the way from the manufacturing stage until it is injected into the patient Vaccines that require refrigeration can be difficult to distribute, particularly in poor countries

Inactivated or killed disease agents Polio Hepatitis a The advantages of these vaccines are that they can’t cause the actual disease and that the purified forms can be stored without refrigeration, which makes them cheaper and easier to distribute globally Disadvantage: The immune response they cause is weaker than the immune response caused by live, attenuated viruses. This weaker immune response means that more booster shots are required to maintain immunity

Subunit/conjugate vaccines subunit and conjugate vaccines help the immune systems of infants and young children recognize the virus by helping their system see it. Hepatitis B Influenza (injection) Pertussis (part of DTaP combined immunization) Pneumococcal Meningococcal HPV

Toxoid (inactivated toxin) Toxoid vaccines help the body develop antibodies to toxins released by bacteria rather than antibodies to the bacteria themselves examples: Diphtheria, tetanus(part of DTaP combined immunization)

DNA Vaccines is a technique for protecting an organism against disease by injecting it with genetically engineered DNA to produce an immunological response. There are many advantages to the DNA vaccination method. For example, it is much cheaper to produce and distribute large amounts of DNA than it is to produce and distribute large amounts of protein. There are many DNA vaccines in clinical and pre-clinical trials, including vaccines for HIV, herpes, hepatitis and influenza.

Recombinant vector vaccines are experimental vaccines similar to DNA vaccines, but they use an attenuated virus or bacterium to introduce microbial DNA to cells of the body. “Vector” refers to the virus or bacterium used as the carrier. Recombinant vector vaccines closely mimic a natural infection and therefore do a good job of stimulating the immune system. Researchers are working on both bacterial and viral- based recombinant vector vaccines for HIV, rabies, and measles.

History of live virus vaccines 1700 – Edward jenner was interested in the belief of farmers that cowpox infection prevented smallpox Jenner deliberately infected people with cowpox, a mild disease related to smallpox After they recovered from cowpox, he attempted to infect them with smallpox What he found: they were immune to smallpox Today his efforts would be considered unethical, but his work saved countless lives

Vaccine fears: fact vs fiction Smallpox vaccineS “eradicated” smallpox. The last case was recorded in 1977 If vaccines were to be stopped, diseases would re-emerge The resurgence in vaccine-preventable diseases is due to the fears many people have about vaccination. Also, increases in immigration and unvaccinated people

Vaccine fears: fact vs fiction Vaccination does have risks, but these risks are far out weighed by the risks of the disease they prevent Example: Risk of death from measles vaccination is less than 1 in 1,000,000 Risk of death from contracting measles is 1 in 1,000 cases In addition, individuals suffer serious complications such as pneumonia and ear infections after contracting the disease

Autism in young children The myth arose from a fraudulent study published in a British medical journal claiming that the mmr (measles/mumps/rubella) vaccine caused autism After this study was published, vaccination rates began to fall Two large studies since have shown there is no connection between vaccination and autism spectrum disorders Further research found that the researchers in the British article actually Changed their results to fit their conclusion

Human papilloma virus (HPV) Gardasil and cervarix – vaccines against hpv, EXCEPT ONES THAT YOU MAY HAVE ALREADY BEEN EXPOSED TO. Hpv is a sexually transmitted disease that causes genital warts (HSV2) and cervical cancer. It has also be linked in vaginal cancers in women and penile cancers in men. Hpv is the most common sexually transmitted disease in the u.s., but most women fight the infection off without treatment

HPV

Human papilloma virus (HPV) Each vaccination requires 3 doses and is relatively expensive, there is no time frame of how long the vaccine will last Cervical cancers affect 11,000 women a year in the u.s. and kills almost 4,000 Worldwide 275,000 women die each year from cervical cancer Most of the cases would be prevented by the vaccination

Female cervix

Gardasil and cervarix Vaccination can prevent abnormal and precancerous cells in the cervix These abnormal cells are found by pap smears Cells are taken from a woman's cervix and examined an abnormal pap smear results in the need for a biopsy The hpv vaccines also can reduce the number of biopsies required

Gardasil and cervarix The vaccination is most effective in young adolescents because they have stronger immune response It is important to be vaccinated before exposure to the disease , IE: BEFORE YOU BECOME SEXUALLY ACTIVE

Gardasil and cervarix Parents and politicians continue to claim it is a dangerous vaccine The fda and government agencies around the world continue to monitor the safety and effectiveness of all vaccines

Vaccine development process Fda must approve vaccines for use in the united states To get approval each new vaccine goes through an extensive development and testing process that builds on lessons from previous vaccination development It must include in vitro testing, animal testing and several phases of clinical trials in humans

Manufacturing vaccines Vaccine antigens are produced under highly regulated conditions Manufacturers follow required good manufacturing practices This ensures the product is the exact dose each time and safe Each phase of the manufacturing must be carefully documented

Manufacturing vaccines There are 3 methods to manufacturing vaccines Eggs Cell culture Plant culture

Eggs- From chicken egg to syringe: how a flu vaccine is made Since the 1940’s influenza has been made by injecting fertilized chicken eggs with live but weakened strains of influenza virus The virus replicates in the egg for several days Then the virus is separated from the egg and exposed to chemicals – this inactivates the virus dna It is tested for sterility and then packaged into vials then tested one last time It takes 5-6 months from the time the new strains of influenza are identified until the vaccine is available for use

Problems with eggs in vaccines Threat of egg shortage due to diseases in chickens The fact that some strains of virus grow more slowly in eggs or have much lower yield of antigen than other strains, will take much longer to make the vaccine If a new deadly strain of pandemic flu emerges, many people might become ill before the vaccine could be ready – researchers are working hard to develop new manufacturing methods

Cell culture-you tube A look inside cell-culture influenza vaccine manufacturing at Holly Springs Antigen is grown in large vats of cells The cells are grown in vats called bioreactors, which are completely closed from any contact with the outside environment to ensure no contamination occurs After they are grown, they are infected with the virus The virus replicates in the cells producing lots of antigen and kill the cells Next the antigen is harvested and purified, tested and then packaged to ship This is a faster process than the egg process

Pharming-youtube Tobacco plants help Fight ebola, flu and more Using plants for the production of vaccines Medicago in research triangle park, nc dedicated to the production of plant-based vaccines Using tobacco plants to make the influenza vaccine This is faster than traditional influenza production This is also safer because they lack dna and is more stable for distribution

Challenges in vaccine research Some disease organisms pose particularly complex problems to vaccine developers We need rapid and economical manufacturing techniques to produce large amounts of vaccine in order to be prepared for the possibility of a rapid emerging pandemic disease Researchers are working on techniques that parents may be able to feed their child a banana instead of a shot!

Virus mutations and vaccines The disease causing virus mutates frequently The mutations cause changes in the antigen proteins found on the surface of the virus Even if a person is vaccinated, changes in these proteins mean that the immune system doesn’t recognize the changeD virus immediately – the immune system can’t fight the virus effectively (SAME IN CANCER CELLS THAT RECUR, THEY HAVE MUTATED AND DON’T RESPOND TO THE SAME CHEMO DRUGS)

The common cold It is impossible to develop a vaccine for the common cold because there is more than 200 strains of viruses that cause the common cold