Human Papilloma Virus (HPV) Vaccine for cervical cancer in women

Human Papilloma Virus (HPV) Vaccine for cervical cancer in women

The most common cause of cervical cancer is HPV 16 and HPV 18, which account for about 70% of cervical cancer cases. Stimulating the body to build immunity against HPV infection is one way to protect the cervix from HPV infection.

Efficacy and Safety of HPV Vaccine

Results of the efficacy and safety study of the HPV 16/18 vaccine showed that the HPV 16/18 vaccine has a high potential for stimulation of immune system.

It has high safely and has no serious side effects.

Moreover, it shows high effecacy against persistent HPV 16/18 infection and prevention of HPV 16/18-induced precancerous cervical lesions.

Recommended age for HPV Vaccine

The HPV vaccine's efficacy is the highest in women who are not HPV-infected, so it should be vaccinated before the age of sexual intercourse or before the first time to prevent HPV infection and subsequent lesions. The HPV vaccine is currently safe and have high immune-stimulating potential for preventing HPV infection and genital lesions in women with age of 9-26 years.

For women over 26 years of age, there is no data on the effectiveness of HPV infection and lesion prevention. For the booster vaccine, it also has no information about an appropriate period. Currently available data show that antibody levels remain protective against HPV infection for at least 5 years.

HPV Vaccine Injections

The HPV vaccine is intramuscularly injected for 0.5 ml three times as follows:

1^st time: inject on the selected day

2^nd time: Inject in the 1-2 month after the first injection

3^rd time: injection on the 6^th month after the first injection

Indications for HPV Vaccine Injections

• To prevent HPV infection with the same strain of the injected vaccine
• To prevent female genital lesions and cancer caused by HPV infection with the same strain of the injected vaccine

Contraindications for HPV Vaccine Injections

• People with hypersensitivity against vaccine constituents, such as yeast and adjuvants
• People with symptoms from the condition of hypersensitivity after the first injection of the HPV vaccine

Advice before the HPV Vaccine injection

The vaccination recipient should be explained as follows:

• The HPV vaccine injection is not a substitute for cervical cancer screening.
• The HPV vaccine might not prevent infection with HPV precancerous lesions and cervical cancer.
• The HPV vaccine cannot prevent abnormal Pap smear results and cannot be used to treat precancerous lesions of the cervix.
• The HPV 16/18 vaccine does not prevent infection or lesions caused by other HPV strains except HPV 16/18.
• The HPV vaccine does not protect against diseases caused, such as vaginal discharge or venereal disease, etc.
• In HPV vaccine in low immunity women, antibody levels may be lower than in normal women.
• After injection of the HPV vaccine, you shouldn't have promiscuous sex. Preventive sex against HPV should also be practiced.
• Three doses of vaccination should be completed.

Side Effects of HPV Vaccine Injections

In general, the HPV vaccine is very safe. Serious side effects are not found. However, possible side effects include:

1. Side effects at the vaccination site, such as pain, swelling, redness and itching, are usually mild. It is temporary and will be disappeared.
2. General symptoms may be found, such as fever found about 10% with a mild symptom and disappear on their own, headache, nausea, vomiting, fatigue, and rash all over the body. These symptoms are mild and disappear on their own.

Cervical cancer screening before and after HPV Vaccine injection

A Pap smear before vaccination depends on sexual history and cervical cancer screening.

1. If you haven't had sex yet, a Pap smear is not required prior to vaccination.
2. If you have had sex,
   1. If you have never done a Pap smear before or if it is irregular, it is recommended to do a Pap smear to screen for cervical cancer first.

• If the results are normal, the vaccine can be administered. and should come for cervical cancer screening according to the doctor's recommendation.
• If the result is abnormal, the standard treatment is needed. If cured, they may provide information and advice about the HPV vaccine for women to consider.
  2. If you have done a Pap smear regularly and the results are normal every time, you can be vaccinated

• After HPV 16/18 vaccine injection, cervical cancer screening should be done regularly because HPV 16 and HPV 18 are responsible for approximately 70% of cervical cancer.

HPV detection before the HPV Vaccine injection

There is no need to check for HPV (HPV test) before HPV vaccine injecting because HPV testing cannot determine whether you have been infected or not. If the results are positive, it can only inform that HPV infection is present. HPV antibody detection is not yet practical. Therefore, it is not recommended to check. Testing for HPV before the HPV vaccine injection increases the cost of vaccination.

Women who have had sex

Women who have had sex before can get the HPV vaccine. Women who have an abnormal Pap smear or a positive HPV test should receive standard care and treatment. However, they can be vaccinated but it should be advised that the efficacy of the vaccine is reduced if previously infected with HPV. After HPV vaccine injection, you still have to come for cervical cancer screening regularly as well.

Women who have had pre-cervical lesions

Women, who have had CIN before, can receive HPV vaccine if they are treated, but they must come for regular follow-up examinations by a doctor. It must be emphasized that if a woman has already been infected with HPV 16/18, the injection of the HPV 16/18 vaccine is not curative and may have low benefit in HPV 16/18 prevention.

Pregnant women and women who are breastfeeding

The HPV vaccine is classified as category B and is not recommended for pregnant women. Although no teratogenicity has been reported in laboratory animals, if you are pregnant while you haven't completed your 3 doses of vaccination, you can complete the next dose in the postpartum period. It is currently unknown whether the antigens of the HPV vaccine and the antibodies produced by the body are transferred through breast milk, but the HPV vaccine contains virus-like particles of HPV that are not infectious. Therefore, has no safety implications for both the mother and the baby.

Women with low immunity

Immunocompetence is not a contraindication to HPV vaccine administration, but the immunization response may be less than in immunocompromised women.

Thai Society of Colposcopy and Cervical Pathology (TSCCP)