BMS2052 Lecture Notes - Lecture 18: Gardasil, B Unit, Antigen
30 May 2018
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Week 7. Vaccinations
VACCINES I
• History of vaccination:
o 1700: Edward Jenner -> milkmaids who had contracted cow pox did not get small pox
o 1796: Jenner scratched boy with needle that had fluid from cowpox infection
o Inoculated boy was later exposed to small pox and was found resistant
• Outcomes of vaccinations:
o Prevention of disease and symptoms
o Prevention of transmission
o Eradication of disease
o Potential treatment of existing disease (i.e. cancers, alzheimers)
• Eradication of smallpox
o Vaccinia – cow pox virus used
o Worldwide eradication began in 1967
o Eradication declared in 1980
o Successful WHO program based on vaccination and quarantine
o Why was it successful?
Disease limited to humans
-does’t hae ultiple reseroirs, easy to quarantine
No long term carriers
Is always recognisable
Few serotypes/variants
Stable and cheap
Effective vaccine available
Eradication is cost effective
Global surveillance
find more resources at oneclass.com
find more resources at oneclass.com
• Polio, rubella, measles, typhoid, HepB may be the next to eradicate
• Polio eradication program:
o Highly infectious viral disease
o Spread through faecal oral route
o Multiplies in intestine and invades nervous system
-> eventually leads to respiratory problems
o Can cause paralysis in matter of hours
o 1 in 200 infections end in irreversible paralysis
o 5-10% mortality rate due to paralysis of breathing muscles
o Limited number of strains
o Alert “ai’s aie OPV a e used orally
o Global cases for 2016 = 17 (has decreased drastically)
o OPV:
Virus can be shed through stools
If not entirely healthy, can get polio -> vaccine associated polio
o Now swapping over from OPV to IPV
-> no chance of reversion
-> huge swapping campaign
• Vaccination achieves:
o Protection of the individual against the disease
o Protection of a population against disease
• Herd immunity:
o Community based disease control by vaccination
o Immunity can protect immunocompromised individuals
o Coverage rates to protect the community need to be 100%
o Insufficient coverage can lead to outbreaks and persistence of disease
o Disease is maintained in the population via pool of unvaccinated individuals
find more resources at oneclass.com
find more resources at oneclass.com
o Vaccine preventable childhood diseases and coverage rates needed to protect the
community:
o Eg. Measles in USA:
Great success by 1983
By 1990 – only 70% coverage, cases began to rise again
Huge public health effort to raise immunisation rate back to 90% range
By 2000, USA declared effectively eradicated with <60 cases per year
2014, measles cases increased due to lack of vaccination
-> importation of measles by non-vaccinated individuals that have travelled to
endemic areas and returned to the USA with infection
-> 1 person can potentially infect 12 other people
-> long latent period
1980 = 2.6 million deaths/year
2000 = 0.5 million deaths/year
2014 = 115,000 deaths/year
-> still a huge global problem
Next target for eradication
• Six diseases that account for 90% deaths from infectious diseases:
1. Tuberculosis
2. Malaria
3. Diarrhoeal diseases
4. Pneumonia
5. Measles
6. HIV/AIDS
o Major killers are illnesses of poverty – many of these are vaccine preventable
o In 2008, WHO estimated that 1.5 million deaths among <5yo children were due to
vaccine-preventable diseases
find more resources at oneclass.com
find more resources at oneclass.com
Document Summary
Vaccines i: history of vaccination, 1700: edward jenner -> milkmaids who had contracted cow pox did not get small pox, 1796: jenner scratched boy with needle that had fluid from cowpox infection. Global surveillance: polio, rubella, measles, typhoid, hepb may be the next to eradicate, polio eradication program, highly infectious viral disease, spread through faecal oral route, multiplies in intestine and invades nervous system. If not entirely healthy, can get polio -> vaccine associated polio: now swapping over from opv to ipv. > huge swapping campaign: vaccination achieves, protection of the individual against the disease, protection of a population against disease, herd immunity, community based disease control by vaccination. Immunity can protect immunocompromised individuals: coverage rates to protect the community need to be 100% Insufficient coverage can lead to outbreaks and persistence of disease: disease is maintained in the population via pool of unvaccinated individuals, vaccine preventable childhood diseases and coverage rates needed to protect the community, eg.
