Missed One HPV Vaccine Dose? Study Reports Two can be as Effective as Three
The human papillomavirus (HPV) is a sexually transmitted infection that could lead to serious health complications, such as cancer and painful genital warts. Since there are over 40 different types of HPV, protecting against the virus via vaccinations was difficult in the past. In current day society, the HPV vaccine known as Gardisil protects the body from at least some of the high-risk strains of the virus that can lead to cervical cancer. Gardisil is recommended for both young girls and boys and needs to be administered three times, each at a particular time span from one another. Due to this strict regimen of the dosages, some people fear that the vaccine could be ineffective after missing one dose. According to a new study, the vaccine appears to be much stronger than previously thought. The researchers, headed by Dr. Simon R.M. Dobson from the University of British Columbia, Vancouver and his colleagues, found that two dosages might be as effective as three in triggering the body to produce the antibodies for the specific strains of HPV.
The researchers recruited 259 Canadian girls from the ages of nine to 13 who had recently received the first two dosages of the HPV vaccine within six months apart. The researchers took blood samples and analyzed the levels of antibodies that were created to protect against the two types of HPV that the vaccines are supposed to protect against. When compared to the levels of antibodies found in teenage girls and women between the ages of 16 and 26 that received all three dosages, the researchers discovered the levels were the same. Furthermore, the girls that were given two dosages maintained the levels of antibodies for two to three years. Although the researchers found that two dosages could protect the body from the virus as effectively as three dosages when administered at an older age, they also found that receiving all three vaccinations duringg one's pre-teen years led to even higher levels of protection.
Since the vaccine is very expensive, the researchers concluded that pre-teen girls can get two vaccinations since they would still be protected. A late booster during the teenage years could then be administered for extra levels of antibodies for adulthood. The researchers and other professionals have commented that hopefully a two-vaccination schedule will prompt parents to be more willing to get the vaccine for their girls. However, they have also acknowledged that the study did not look into girls from the ages of 13 to 16 nor did it look at the effects in boys.
The study was published in the Journal of the American Medical Association (JAMA). A video explaining the study can be found here.