Aim: How do vaccinations protect us against disease ?

Immunity is the ability of an organism to resist disease by identifying and destroying foreign

substances or organisms.

Active immunity

• Naturally acquired active immunity occurs when the person is exposed to a live pathogen, develops the disease, and becomes immune as a result of the primary immune response

• Artificially acquired active immunity can be induced by a vaccine, a substance that contains the antigen.

and cells…

Vaccination

• means of producing immunity against pathogens, such as viruses and bacteria, by the introduction of live, killed, or altered antigens that stimulate the body to produce antibodies against more dangerous forms.

Vaccine is made from

• an antigen isolated or produced from the disease-causing microorganism

• vaccine is injected into the blood stream. The B cells in the blood stream respond to the antigen by producing antibodies

• antibodies bind to the antigen to "neutralize"or inactivate it

• memory cells are produced and remain ready to mount a quick protective immune response against subsequent infection with the same disease causing agent.

Memory Cells and Immunity

Vaccine Mass Production

There is no vaccine for the HIV virus

Electron Micrographs and schematic of HIV

Yellow – lipid bilayer

Red, Black & green – different proteins

HIV attacks the CD4 immune cell

Macrophage

T Cell

Helper T Cell

Killer T Cell

Infected CellAntigens are displayed on surface of macrophage

T cell binds to activated macrophage

T cell, activated by macrophage, becomes a helper T cell

Helper T cell activates killer T cells and B cells

Killer T cells bind to infected cells, disrupting their cell membranes and destroying them

Section 40-2Normal function of a T Cell

HIV affects T-cells

• A normal T cell count is usually over 1000, although it may dip occasionally to even 400 in response to other infections.

• In HIV we see a drop in T cells (CD4 cells) over time which does not recover without adequate and long-term control of the HIV virus.

HIV doesn't kill anybody directly…

instead, it weakens the body's ability to fight disease.

Recommended Vaccinations:

• Hepatitis B • Pneumococcal conjugate vaccine (PCV) • DTaP (diphtheria, tetanus, acellular pertussis) • Hib (meningitis) • IPV (polio) • Influenza • MMR (measles, mumps, rubella) • Varicella (chickenpox) • MCV4 (bacterial meningitis) • Hepatitis A

The Pros and Cons of Vaccinations

The practice of vaccinating ourselves, our children, and our animals to prevent disease is the subject of a great deal of debate. Heated discussions arise over what to vaccinate with, when to vaccinate, who to vaccinate, and even whether to vaccinate at all.

New vaccine to Guard Against HPV

• PBL

HPV and Cervical Cancer

Part I “One Less” and “Tell Someone”

Aim: How does the HPV vaccine work to prevent cancer?

WILMOT CANCER CENTER

University of Rochester

We developed a vaccine that could eliminate one cancer from the earth

Understanding Cancer and Related Topics

HPV Vaccine To Prevent Cervical Cancer

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The VLP-based vaccine prevents HPV infections from triggering cervical cancer by inducing a strong protective immune response

Common Infection

Infected with HPV

At least 70 % of sexually active persons will be infected with genital HPV at some time in their lives

Infection Is Sexually Transmitted

Anyone who has ever had genital contact with another person infected with HPV can get the infection and pass it to another person

Many Types of HPVs

Different HPVs–Different Infections

Harmless

No warts or cancer

Warts-Linked

Genital warts

Cancer-Linked

Most clear up

Some persist, but no abnormalities in cervix

Some persist, some abnormalities in cervix

A few persist and progress to cervical cancer

Virus Penetrates Cervix

Uterus

HPVinfection

Vagina

Cervix

Layers of epithelial cells

Papillomavirus

Human papillomaviruses pass by skin to skin contact

Virus Uncoats

Virus “uncoats”

Nucleus

Epithelial cell interior

mRNAs for viral proteins E6 and E7

Viral DNA enters nucleus

Virus Disables Suppressors

Cancerous epithelial cells

Suppressor protein 2

E7 viral protein

Degraded suppressors

Healthy cellsMucus

E6 viral protein

Suppressor protein 1

Viral proteins disable the normal suppressor genes (“damage surveillance”)

Virus-Like Particles in the HPV vaccine have no genetic material inside but

induces the immune response

The Vaccination

The vaccination protects a person from future infection by the HPV high-risk types

Antibodies Prevent Infection by coating the antigen of the virus

Papillomavirus

No DNA strands can escape the capsid= Antibodies

How do we detect abnormal cervical cell growth?

Normal Pap smear

Abnormal Pap smear

More Work Ahead

4 years later