A study spanning over a decade confirms the efficacy of the HPV vaccine against the Human Papillomavirus in patients aged up to twenty years, confirming the WHO vaccination guidelines for adults.
As per the recent research published in the Journal of Human Vaccines and Immunotherapeutics, it was observed that the patients who were administered the vaccine at the age of up to twenty years, were protected against Human Papillomavirus.
- As per the findings of this research, it was discovered that the administration of a single dose of the HPV Vaccine provided a substantial number of antibody responses against both type 16 and type 18 Human Papillomavirus in both groups. Participants of the younger groups aged between 10 to 14 years while the older group aged between 16 to 20 years.
- Furthermore, a decreased level of antibodies was observed in participants who were administered one dose of vaccine as compared to the ones who were administered more than one dose of the vaccine. This change in the level of antibodies was more evident in the young participants.
- In addition, the research complied with the recommendation of World Health Organization to administer one dose of HPV Vaccine in the age group ranging to twenty years. This strategy may allow us to target a much larger segment of young females.
- Additionally, the age of administration of the vaccine was found an important factor in determining the level of antibodies as the younger age group demonstrated higher levels of antibodies than the older age group.
- Nonetheless, the research indicated the significance of evaluating the effectiveness of the HPV vaccine in the long term while compiling the WHO guidelines for the aforementioned vaccine administration.
As per the guidelines published by the World Health Organization in 2022 to lower the risk of cervical cancer, patients. aged 9-20 years, should be administered with at least one dose of the HPV vaccine to eliminate the risk for a lifetime.
The study has found that the level of antibodies was half in females aged between 18 to 25 years as compared to those aged from 10 to 17 years, which raised concern about immunity from the Human Papillomavirus in the women who were administered the vaccine after fifteen years.
The long-term immunity after ten years of administration of the vaccine in both younger age groups and older age groups was determined in a study, taking the number of doses into account as well.
Two cohorts were involved in the research where each cohort received two doses. The first cohort received doses on the first day and after six months or beyond. The second cohort received doses on the first day and end of the second month. The group receiving three doses had more than 4300 participants, while the group receiving two doses had up to 8450 participants in a total of both categories, and the group which received one dose had around 5000 participants. Additionally, a comparative cohort comprised more than 1,450 married women who remained unvaccinated throughout the study duration.
The blood samples of the participants were obtained after ten years of administration vaccine as the follow-up of the study was planned till 2016. In addition, the samples from the cervical region were also collected consecutively for four years and evaluated.
Blood samples were obtained on the first day of the study which was documented across all cohorts. For the cohorts receiving two doses and three doses, additional blood samples were collected at the end of the second month. The remaining two cohorts provided blood samples at the end of the first and second years. Subsequently, blood samples were collected from all cohorts at the end of 18 months, 26 months, 04 years, and 05 years. In the case of the cohort receiving one dose, blood sample was collected after the end of a decade from participants who had undergone initial and yearly sample collection.
The researchers evaluated the samples of type 16 and type 18 of HPV to determine the number of antibodies present in the aforementioned samples. The neutralizing effect of antibodies against the HPV-L1 protein of type 16 and type 18 of HPV was also determined.
Among the study participants, more than sixty percent received vaccinations during the age range of ten to fourteen years. Notably, more than thirty-two percent of individuals who had not received any vaccination, around twenty-five percent of those with one dose, around thirty-one percent of those with two doses, and thirty percent of those with three doses were aged 26 years or older at the time of serology sample collection. All of the non-vaccinated group was married, while more than seventy percent of one dose cohort was married. Marriage status was indicated by sixty and seventy percent in the remaining aforementioned groups, respectively.
Most individuals who were administered a single dose of vaccine noticed binding antibodies against types 16 and 18 of HPV, which remained the same after a decade of vaccination in both groups. In the young population group, the prevalence of detectable binding antibody titers for type 16 and type 18 of HPV stood at around 98% in both. Correspondingly, in the older age group, these rates were around 92% for type 16 and 94% for type 18 of HPV.
In individuals who were administered the vaccine at ages 10 to 14 years, a notable 2.1 times elevation in the geometric mean titer for binding antibodies against type 16 of HPV was observed, countering with a 1.9 times addition in those vaccinated between ages 15 years and 18 years. Whereas, HPV type 16 of HPV showed a reduction of eleven percent among recipients of a single dose in the age group ranging between 15 years to 18 years compared to their counterparts vaccinated between the ages of 10 years and 14 years.
Identical trends were observed in the kinetics of binding antibody GMTs against type 18 of HPV. Specifically, a substantial 3.7 times rise in the decade-long GMT against type 18 of HPV was also noted in one dose recipients aged between 10 years and 14 years, corresponding with a 3.1 times increase in the participants aged between 15 years to 18 years. In addition, for both types 16 and 18 of HPV, recipients of a single dose exhibited lower mean GMTs when compared to their counterparts who received two or three doses.
The research indicated the significance of evaluating the effectiveness of the HPV vaccine in the long term while compiling the WHO guidelines for the aforementioned vaccine administration.
Bhatla N, Muwonge R, Malvi SG, et al. Impact of age at vaccination and cervical HPV infection status on binding and neutralizing antibody titers at 10 years after receiving single or higher doses of quadrivalent HPV vaccine. Hum Vaccin Immunother. 2023;19(3):1-6. doi: 10.1080/21645515.2023.2289242.