HPV Vaccine Provides Years of Cancer Protection

It is anticipated that 80% of people will be infected with the human papillomavirus (HPV) at some point in their lives.
Although many infections go unnoticed, some strains of HPV can damage DNA, leading to malignancies such as cervical, anal, and oropharyngeal (throat). Cervical cancer is the fourth highest cause of cancer deaths in women globally, accounting for 88% of cases in low and middle-income countries (LMICs). Fortunately, most cervical cancers can be avoided by immunization. The introduction of HPV vaccine has transformed the fight against this virus. HPV vaccine alongside surgical treatment for cervical lesions reduces the risk of further diseases. Extensive research has shown that HPV vaccines are highly efficient in preventing infections and consequent malignancies. Despite this, just 13% of girls worldwide are vaccinated as of 2021.

Initially, two or three doses of vaccine were suggested to ensure best protection.

Recent studies, however, have demonstrated the exceptional efficiency of a single dosage, particularly in LMICs where the execution of multi-dose vaccination programs presents several problems. High expenses, complicated logistics, and a limited healthcare infrastructure are among them.

The efficacy of a single dose
Our most recent trial, which included over 800 women in Fiji, discovered that the HPV vaccine was very effective against the detection of two HPV strains that cause cancer for up to eight years after immunization.

This research was conducted in collaboration with the Fiji Ministry of Health and Medical Services and was published in The Lancet Regional Western Pacific.

The vaccine was 81% effective against the two most common strains, HPV 16 and 18, which account for almost 70% of all cervical cancer occurrences in Fiji and around the world.

Due to terrain, distributing vaccines to isolated villages and people is especially difficult in Pacific Island Countries and Papua New Guinea. As a result, the availability of a single-dose HPV vaccine provides an important chance to overcome these barriers and protect vulnerable groups.

A recent high-quality trial in Kenyan women aged 15-20 years backs up this method.

The study discovered that a single dose of the HPV vaccine had the same efficiency (97.5%) as two or three doses at 18 months following immunization in preventing HPV types 16 and 18.

One dose provides years of immunological protection

Furthermore, several observational studies have indicated that even in those who had previously been exposed to HPV, a single treatment greatly reduced the likelihood of acquiring pre-cancerous lesions.

These findings show the extraordinary potency of a single HPV vaccine dosage and its ability to avert the devastation caused by HPV-related illnesses.

Five observational studies, including those from LMIC settings, indicated that a single dose provided comparable protection to two or three doses against HPV types 16 and 18.

The longest follow-up period for evaluating the effectiveness of a single dosage against cervical dysplasia was 14 years after immunization. In a US observational trial, the longest follow-up time to examine the duration of protection following a single treatment against HPV detection was 12 years.

An prior study conducted by our team in Fiji examined the immune response in women who got zero, one, two, or three doses of vaccination and discovered that the immune response elicited by a single dosage of the vaccine can last for several years, providing long-term protection against HPV-related disorders.

Given the comparable immunological response reported 24 months after vaccination in the Kenyan clinical trial, the lifetime duration of protection from a single dose is anticipated to be equivalent to two or three doses.

Assistance with single-dose immunization programs
The decreased cost of a single-dose regimen makes immunization programs more accessible and cheap, which can have a transformative influence in LMICs. The financial burden on health care systems and individuals is greatly reduced by lowering the number of required dosages.

This cost makes statewide HPV immunization efforts more feasible and increases vaccine coverage, ensuring a broader reach and higher protection against HPV-related diseases.

Furthermore, given the global HPV vaccine deficit until 2024, a single-dose schedule may allow more girls to be vaccinated and women to be protected. The logistical benefits of a single-dose vaccine also make vaccine distribution and administration easier.

A single-dose strategy improves the overall success of vaccination programs in distant or underserved areas with inadequate health care facilities, reducing missed opportunities for individuals to acquire HPV protection.

The World Health Organization (WHO) changed their HPV vaccine recommendations last year, and now recommends one or two doses for girls under the age of 15.

Because of the robustness of the evidence showing a single-dose technique is highly effective, Australia and Ireland have embraced it so far.

A single dosage of the HPV vaccine is extremely valuable, especially for LMICS.

The remarkable efficacy of a single dose in preventing HPV infections and malignancies, as well as its affordability and logistical benefits, make it a vital instrument in the fight against this lethal virus.

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