Great news about reducing cancer risk. Nothing controversial here…
There is early evidence from a recent Pediatrics study that the HPV vaccine is doing what it was intended to do: decrease the rates of HPV infection in teens and young adults. The study compared HPV in two groups of teen girls and young women–one group during a time prior to the vaccine being used (pre-vaccine era 2003-2006) and another group of similar girls and young women after the vaccine’s introduction (vaccine era 2009-2012). They evaluated prevalence of HPV infection in both groups (from cervicovaginal swabs) to see the effects of the vaccine on the population. The DNA tests from those swabs identified evidence of HPV infection from HPV strains that have been included in the vaccine and also additional strains of HPV infections not previously in the vaccine. Researchers also had information about the girls’ self-reported vaccine status and behavior (sexual activity).
The results are exciting and hopeful when it comes to protection from HPV vaccine.
The study shows a 64% decrease in HPV strains found within the vaccine in immunized girls ages 14-19 and a 34% decrease in HPV in girls ages 20-24 who had received the HPV shot. In my opinion, there are 2 big takeaways to this progress and learning:
- The vaccine is effective in protecting teens from acquiring HPV, especially so during teen years. When the shot was given in younger teens they were more likely to have better protection — likely because they are immunized early and thus if/when exposed to HPV infections during their life, they were already protected.
- The earlier the HPV vaccine is given, the better the hope for protection against HPV during teen and young adult years. No safety benefit in waiting to be immunized — the risks are the same from the injection but waiting allows more time when a teen could be exposed to HPV. The data out last month may also reflect previous research that the immune response is better when the immunization is given to younger girls and boys (age 11 for example, over age 16 years).
When the researchers looked only at those who had been vaccinated, they found that overall rates of HPV of any strain weren’t much different before and after the vaccine—but there was a huge drop in infections caused by the four strains covered by the vaccine. The reduction in HPV infections also did not occur due to changes in sexual behaviors.” ~ Tara Haelle, reporter in Forbes
About HPV Infection And Risks
- The Centers for Disease Control (CDC) reports that about 79 million Americans are currently infected with HPV. It’s common, the most common sexually transmitted infection in the United States. Thankfully, most of the time it comes into our bodies and our immune systems clear the infection or people are left with warts or skin growths. But, as you know, sometimes certain strains can come in and cause more concerning changes. Those at the cellular level can lead to more rapid growth and even cancer of the cervix, anus or throat.
- HPV vaccine is given ideally before any exposure to HPV (hence why the age recommendations are for age 11). This past year, The recommendations to start at age 9 years were included for children who have been victims of sexual abuse and may have been exposed to HPV earlier in life. So earlier is better. However, it is also recommended that all teens and young adults get the vaccine even if after an exposure to HPV or even after you’ve had a documented infection from HPV. Because there are multiple strains, there is added benefit to getting your immune system protected.
The HPV Vaccine
- The CDC recommends that all girls and boys receive 3 doses of the HPV vaccine starting at age 11. It’s 3 doses meaning you get one injection, then return 2 months later, and then return again 4 months after the 2nd dose. In the US we’ve had a hard time getting all who start the series to complete it because it’s a busy time in life and many teens just don’t return back to clinic.
- Most children, and nearly all boys, have received the vaccine that included 4 strains or types of the virus (6,11,16,18) but now the new vaccine includes a total of 9 strains (same 4 strains with 5 additional). Better protection coming to all of those getting the vaccine and their partners!
- This study also found evidence for potential “cross-protection” from the vaccine. Because there are hundreds of different strains of HPV, strains selected for the vaccine were intentional for those most likely to cause the most disease (cancer). But sometimes immunizing for one strain can protect against another, meaning that even when immunized for one type or strain of HPV (strain 11, for example) the immune system may help protect you when you’re exposed to another (strain 33, for example). In the study, they found some decrease in HPV 31, 33, and 45 in the vaccine-era girls even though strains weren’t included in the original vaccine. It will be difficult to detect cross-protection moving forward as the vaccine includes more strains.
- If given prior to exposure to more dangerous strains of HPV, the vaccine can potentially prevent up to 90% of cervical, vulvar, vaginal and anal cancers.
- Having the HPV vaccine isn’t a 100% guarantee to avoid cervical cancer. It’s recommended that girls and women still have routine pap smears after the age of 21 years. Prior to age 21 years, paps are done if concerns for changes to the cervix or concerns for abnormal findings, symptoms, or sexually-transmitted infections. So this is still true: get screened for cervical cancer – women aged 21 to 65 years old! Here’s a video about pap smear recommendations for teens: