Human papillomavirus vaccination – an overview

Human papillomavirus (HPV) vaccination is used to prevent human papillomavirus disease which is a sexually transmitted pathogenic disease affecting both males and females. HPV mainly affects oropharyngeal and anogenital tracts.

HPV genotypes are the major cause of almost all cancer of cervix. HPV also cause cancers of anus, vagina, oropharynx, penile and vulvar cancer.

Vaccine helps to protect against the infection and appearance of associated lesions. The available vaccines include:

  • Gardasil – quadrivalent vaccine targeting the type 6, 11, 16 and 18 of HPV
  • Gardasil 9 – this 9- valent vaccine covers all target type of quadrivalent vaccine. In addition to that, it also covers types 31, 33, 45, 52 and 58.
  • Cervarix – bivalent vaccine targeting type 16 and 18

In US, only 9 valent vaccine is used.

Rationale of vaccine administration

Females

All the three vaccines (Gardasil, Gardasil – 9 and Cervarix) ensure a direct protection from infection and resultant cancer. All three vaccines mainly targets type 16 and 18, which is responsible for 70% of all cancers, 90% of anal cancers and majority of vulvar, vaginal and oropharyngeal cancers. HPV vaccines (except Cervarix) protect against anogenital warts.

Males

HPV type 16 and 18 cause majority of anal, penis and oropharyngeal cancers. The burden of cancers is less in males when compared to females.

Administration of HPV vaccines

Age and indication

  • Females: recommended at age 11 to 12 years. It can be administered starting from age 9. In unvaccinated individuals, catch up schedule should be recommended in age 13 – 26 years.
  • Males: recommended at age 11 to 12 years. It can be administered starting from age 9. In unvaccinated individuals, catch up schedule should be recommended in age 13 – 26 years.

In homosexual males and immunocompromised catch up schedule should be initiated at age 22 – 26.

Optimal timing

Immunization is best to be administered before an individual’s debut sex. Persons with an abnormal Papanicolaou test, HPV infection or genital warts should also receive vaccination.

Choice of vaccine

The greater coverage is provided by the 9- valent vaccine than the quadrivalent vaccine. In US, only 9 valent vaccine is used.

Immunization schedule

  • Individuals vaccinating before 15 years of age

Two doses given at 6 – 12 months interval

  • Individuals vaccinating after 15 years of age

Three doses given within second dose after 1 – 2 month of first dose and third dose after 6 months of the first month

  • Immunocompromised individuals

Three doses for any age group given at 0, 1-2 month and 6 months.

Missed dose/schedule

In case of missed dose, resume to the schedule without restarting the series.

Post-vaccination guidelines

All the individuals should be taken for a waiting period of at least 15 minutes in a sitting or supine positing because of the occurance of potential syncope.

Special considerations

Pregnant women: not recommended because of the limited safety profile.

Breastfeeding women: can receive vaccination

Pre-existing HPV and associated disease: genital warts, positive HPV test and cancer of cervix or anogenital tract should receive vaccination

Immunocompromised individuals: are at risk of HPV infection. A three dose schedule (0. 1-2 and 6 months) is recommended.

Efficacy and immunogenicity

≥95% seroconversion rate is found in males and females of all ages.

Vaccine safety

A large safety profile is seen in all clinical trails.

Jose J Kochuparambil

I love the quote -' be the change that you wanna see in others'

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