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Vaccines Against Viral Infection. Austin Follett Medicinal Chemistry. Anti-Viral Vaccines. History Vaccine types How they work Recommended Schedule Specific Vaccines Flu HIV/AIDS Human Papillomavirus (HPV) To stick or not to stick?. History of Vaccines.
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Vaccines Against Viral Infection Austin Follett Medicinal Chemistry
Anti-Viral Vaccines • History • Vaccine types • How they work • Recommended Schedule • Specific Vaccines • Flu • HIV/AIDS • Human Papillomavirus (HPV) • To stick or not to stick?
History of Vaccines • Chinese inoculated themselves against smallpox before 200 B.C. • Edward Jenner inoculated against smallpox with cowpox in 1796 • Vaccination comes from Latin (vacca– cow) • Louis Pasteur took the concept and applied it to prevent against anthrax and viral rabies • 1988: W.H.O. targets polio for eradication • 2000: Global Alliance for Vaccines and Immunization formed; strengthens routine vaccinations in countries with GDP below $1000 • Currently, nearly two dozen vaccines are available for use in the United States
Types of Viral Vaccines • Inactivated: Virus particles are grown then killed by either heat or formaldehyde • Attentuated: Live, weakened form of the virus particles • Subunit: Only given antigen of virus • Isolation of specific protein • Recombinant administration
Vaccination Schedule • By age two, children are recommended to have the following vaccines by the Advisory Committee on Immunization Practices: • Hepatitis A & B, Polio, Measles, Mumps, Rubella, Diptheria, Pertussis, Tetanus, HiB, Chicken Pox, Rotavirus, Influenza, Meningococcal disease, and Pneumonia
Flu Vaccine • Virus has 8 piece genome undergoes antigenic drift • The flu kills 36,000 in the US annually • Flu vaccine is an educated guess of the most probable form of virus • Two main types: • Flu shot: inactivated vaccine • Nasal-spray: attentuated vaccine
Should you get vaccinated? • Yes, if you are at high risk or care for someone who is • No, if you are allergic to chicken eggs or are otherwise immunocompromised • Side effects: • Possible virulence from nasal-spray • Soreness, redness • Low-grade fever • Aches
HIV Vaccine • An effective HIV Vaccine would allow the body to completely rid itself of the virus and/or control it to prevent infection and transmission • Three types being used: subunit, recombinant, and DNA vaccines • http://www.hopkins-aids.edu/hiv_lifecycle/hivcycle_txt.html
HIV Methods of Prevention • Prevent fusion to host cell • Inhibit reverse transcriptase • Inhibit integrase: no viral integration into host genome • Target protease: prevent polypeptide cleavage, functional HIV proteins • Prevent release from host cell
Where’s the vaccine? • Several challenges arise with development: • HIV continually mutates and recombines • HIV infects Helper T cells • Can be transmitted as both free virus and in infected cells • Researchers are unsure what constitutes an effective immune response to HIV • No ideal animal model for testing exists • Possibility that HIV is not the true cause for AIDS
Human Papillomavirus Vaccine • HPV is required in the development of nearly all types of cervical cancer • Vaccination prevents initial infection by several of the most commonly sexually transmitted HPV types • Estimated that 50% of men and women will become infected with one of the sexually transmitted HPV types during adulthood. • Along with cervical cancer, HPV can cause skin and genital warts as well as anal cancer and penile cancer
The Vaccine • All types of HPV do not cause cancer, but a vaccine has been developed that protects against types 6, 11, 16 and 18, which cause 70% of cervical cancers and 90% of genital warts combined • However, other types can cause the cancer, so Pap smears are recommended to prevent cancer development
Gardasil • On February 2, 2007 Texas Governor Rick Perry mandated that all school girls going into sixth grade be vaccinated • Studies have only been done in short duration, long-term impact unknown • In 2006, estimated that 9,700 women developed cervical cancer, 38% died • Although all cervical cancer types are not covered by this vaccine, this prevalence would be greatly reduced by widespread vaccination • Currently, multiple groups nationwide question the value of the vaccine as a whole; safety issues seem to have fallen under the importance of speed. • In addition, other high-risk HPV types can circumvent the vaccine completely, reducing its effectiveness.
To: Vaccinations prevent viral infections, most effective way of disease prevention Cost-effective method to manage healthcare Herd immunity could extend to those that don’t get the vaccine Not to: Certain vaccinations have not been tested completely Compulsory vaccination represents excessive government interaction Childhood vaccinations contain mercury, which has a possible connection with autism (MMR, DTP, HiB, Hep. B) Controversy:To Stick or Not To Stick?