Human papillomavirus vaccines

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Human papillomavirus vaccines
The development that will saves womens lives
Dr. Enas Mehdi Al-akkam Al-Hillah General
Teaching Hospital
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Why we need HPV vaccines ?

• The relationship between Human papillomavirus
  HPV and cervical cancer has been confirmed, it
  is responsible for 99.7 of cervical cancer
  particularly HPV 16 and 18 which are
  responsible for 70 of cases.
• More than 80 of females get HPV infection at
  some point in their lives.
• Studies suggest that the vaccine can be 100
  effective in blocking two virus strains HPV 16
  and 18 and subsequently can prevent up to 70
  of cervical cancers, That is to say it can save 7
  from 10 women from being affected by cervical
  cancer.

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How does the vaccine work ?
The vaccine is a Viruslike particles VLPs
, it has the outer capsid of HPV and looks
morphologically similar to The virus, it is
highly immunogenic and can generate neutralizing
antibodies that can prevent infection in
subsequent exposure. In addition, they are not
infectious by themselves as they dont have the
oncogenic viral DNA core.
Diagrammatic representation of (HPV) virion and
an HPV -VLP demonstrating structural similarity
without the oncogenic viral DNA core
Electron micrograph of HPV16 L1 VLPs.
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Types

• There are two new vaccines against HPV
• Quadrivalent vaccine Gardasil licensed by the
  FDA and European Union, it provides protection
  against 4 types 6, 11, 16 and 18.
• Bivalent vaccine Cervarix protects against
  type 16 18.
• Cross protection against other HPV types is
  possible.

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The decision that will saves women's lives

• The English Government has announced
  that from September 2008, all girls aged 12 or
  13 in England will be routinely offered the HPV
  vaccine. 
• They also announced a 2 year 'catch up'
  programme, starting in Autumn 2009, to vaccinate
  girls under the age of 18.

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Schedule
Vaccination will be most effective if introduced
prior to onset of sexual activity therefore, the
target will be girls of 1213 years old. The
vaccine is given by injection into the muscle of
the upper arm or upper thigh in three doses over
six months. Minor side-effects like soreness at
the injection site and fever can occur. Rarely
it can cause joint pain and urticaria and very
rarely bronchospasm. The protection offered by
the vaccines lasts at least five years but is
probably life long. At the moment boosters are
not thought to be needed.
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Will the HPV vaccine replace cervical screening
programme ?
The vaccine protects against 70 per cent of
cervical cancers that is caused by HPV-16 18 and
still there is chance of developing the cancer
due to other HPV strains like 31,33,35,39,45,51,56
,58,59,68,73 and 82. Therefore, for the moment,
adult females should continue to rely on Pap
smear tests and it seems probable that this will
be so for at least the next 20 years because the
majority of women already have HPV infection
before the vaccines are induced.
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Developing countries
In many developing countries which lack organized
screening programmes, cervical cancer is the
leading cause of female cancer deaths. Such
countries would benefit enormously from an
effective HPV vaccine. The draw back of the
vaccine is that it is expensive, 3 doses are
needed and it is administered by
injection. Therefore, a second generation HPV
vaccines are required that can be produced more
cheaply and to be administered as a single dose.
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Conclusion
Its really looks like that the use of HPV
vaccines is the beginning of the end for
HPV-associated diseases in women.
Vaccines by themselves are safe and effective,
however, the real benefit of a vaccination
programme will take 10-20 years to be realized.
Thank you