the present situation the strategies the vaccination the controversy
TRANSCRIPT
The Present Situation
The Strategies
The Vaccination
The Controversy
The Fight Against Measles
• About 20 million cases each year around the globe.
2011
UK- 804 cases
Ireland – 173 cases
Europe - more than 26,000 cases
8 deaths
24 cases measles encephalitis
• Africa and Asia , remains one of leading causes of death in children. – WHO - 164,000 people died from measles in 2008, most younger than 5 years old.
Recent Outbreaks
•Increase in measles cases and deaths in recent months
•Prevalent in famine and drought areas
•Unvaccinated children forced to live in cramped refugee camps
•Somalia – 24%of 1yr olds immunized in country
Recent Outbreaks (2)
Increase in US cases
•over 92% population vaccinated•Dropped due to importation of disease from WHO European Regions and South East Asian regions.•33 countries in WHO European Region have increased measles cases
Eradication
MMR Vaccine
Developed in 1960s by Maurice Hilleman
3 live attenuated viruses
First dose ~1 year, second ~5 years.
Before vaccination, measles “as inevitable as death and taxes”.
Now contracted by <1% of individuals under 30 in countries with routine childhood vaccination
Prevents illness, disability, death.
WHO Strategy 1994 - 2004
Aim: Vaccinate >90% in all districts
All children to get second dose
71% of targeted children in 1999 -> 76% in 2004
Sub-Saharan Africa – 49% -> 65%
South Asia – 54% -> 61%
2004 – 168 counties (88%) offered second round
MMR in Ireland
First dose at 12 months
Second dose (not booster) at 4-5 years
Through school/HSE or GP
Recent outbreaks of measles and mumps due to missed second dose
1985 - Monocomponent measles vaccine introduced- 10,000 cases in that year reduced to 201 in 1987
1988- combined MMR introduced -12-15months
1992- Second dose recommended- 10-15 years
1999- Age of second dose reduced to 4-5 years
Childhood vaccination Schedule for children born after 1st July 2008- Free From the Department of Health, HSE• 12months from GP
• 4-5 yrs from GP or in School
• Primary School Immunisation Programme
Vaccination Strategy- Ireland
Outbreak in 1993- affected 4,000 people
2000- 1,600 cases resulted in 3 deaths
From 2001 to 2006 – 1,562 cases • Rapid spread during these outbreaks due to:• Incomplete vaccination coverage
• Susceptible pool of older unvaccinated children
Today- 221cases reported in 2011, so far (411 in 2010)• 85% occurred in North Dublin City
90% of children have received 1st dose by 24months
Global mortality reduced by 78% , from estimated 733 000 deaths in 2000 to an estimated 164 000 deaths in 2008-78%
The WHO region of America has
sustained elimination since 2002
The WHO has set a target of
elimation of measles in
remaining 4 out of 5
WHO regions by 2020.• This can only be achieved by
Increasing routine immunization coverage• improving surveillance systems• political and financial commitment
W.H.O-Measles Eradication
• There are two treatments to protect against measles:
• MMR: measles, mumps and rubella vaccine.
• MMRV: measles, mumps, rubella, and varicella vaccine.
Vaccination
• From nucleotide tests all vaccines were shown to be similar.
• At present the MMR vaccine has a 95% efficiency.
• First virus was obtained from David Edmonston in 1954.
• The virus strain was grown in chick embryos.
• Made the virus more suited to chicks than humans
• Similar attenuated vaccines around this time were developed.
Development
• Control: reduce incidence of disease. Due to 95% efficiency a two dose strategy is need to prevent an accumulation of susceptible individuals.
• In 2010, about 85% of the world's children received one dose of measles vaccine by their first birthday through routine health services – up from 72% in 2000. Two doses of the vaccine are recommended to ensure immunity, as about 15% of vaccinated children fail to develop immunity from the first dose.
WHO: Eradiation PolicyControl
Outbreak Prevention
Eradication
Children should be vaccinated with the MMR vaccine 12 to 15 months after birth and should receive a second dose at 4-5 year usually before the child enters school.
Before the vaccination programme was implemented in USA, between 3 to 4 million people were infected each year, with 400 to 500 dying
Measles is a highly contagious virus and was estimated there was 242,000 Measles deaths which equals 27 deaths every hour.
Measles Vaccine
• The vaccine like many vaccines can cause allergic reactions, most people however do not have any problems with it.
• Mild problems: fever (1 in 6 doses), mild rash ( 1 in 20) or rare swelling of glands.
• Moderate problems: seizure (1 in 3,000 doses), temporary pain in joints ( 1 in 4 teenage and adult women) and temporary low platelet counts which can lead to a bleeding disorder ( 1 in 30,000 doses).
• Sever problems: 1 in 1 million: deafness, long-term seizures or comas and permanent brain damage.
MMR Vaccine Risks
• Has a fever
• Is taking steroids
• Has had another live attenuated vaccine in the last three days
• Is receiving chemotherapy/radiotherapy
• Has a compromised immune system
Less safe if recipient...
Developing Countries Immunodeficiency
Individuals with low immune responses can’t handle certain vaccines due to the presence of attenuated or live virus.
• Presence of maternal antibodies during first 9 months of life reduces efficiency of immunization.
• Measles virus infects children by the respiratory tracts and little of the maternal antibodies will be transduced onto mucosal surfaces
Problems with Vaccine
Aerosol delivery and high titre vaccinations to overcome problems in vaccinating young infants.
1. Recombinant virus
2. Immune-stimulating complexes
3. DNA vaccination
Advancements
Controversy:Wakefield et al. 1998
• 12 Children with Gastrointestinal symptoms, lost acquired skills including communication
• In 8 children, parents and/or physicians linked onset of behavioural problems with MMR
• Main cause of public concern
Wakefield et al. 1998
• Wakefield: “I cannot support the continued use of these vaccines in combination…”
• Public uproar & slump in MMR vaccinations
• Brian Deer Sunday Times investigation 2003-2011
• Prof. John O’ Leary slander
Media Coverage
• Hornig et al. 2008 replications
• Wakefield foul play
Evidence against autism link & aftermath of investigation
Referenceshttp://www.immunisation.ie/en/Downloads/NIACGuidelines/PDFFile_15482_en.pdf
http://www.irishhealth.com/article.html?id=780
http://www.immunisation.ie/en/Downloads/PDFFile_15371_en.pdf
http://www.who.int/immunization_monitoring/diseases/measlesreportedcasesbycountry.pdf
http://www.immunisation.ie/en/ChildhoodImmunisation/PrimaryImmunisationSchedule/
http://apps.who.int/gb/ebwha/pdf_files/WHA63/A63_18-en.pdf
http://www.who.int/immunization/newsroom/news_wha_2010_measles_eradication/en/index.html
www.braindeer.com
http://www.who.int/mediacentre/factsheets/fs286/en/
http://www.cdc.gov/vaccines/vpd-vac/measles/default.htm
http://www.immunisation.ie/en/ChildhoodImmunisation/VaccinePreventableDiseases/MMR/
J. Wakefield, S. H. Murch, A. Anthony, J. Linnell, D. M. Casson, M. Malik, M. Berelowitz, A. P. Dhillon, M. A. Thomson (1998). Ileal-lymphoid-nodular hyperplasia, non-specific colitis, and pervasive developmental disorder in children.
T. F. Wild (1999) Measles vaccines, new developments and immunization strategies. Vaccine 17; 1726-1729.