New study clears Merck's blockbuster Gardasil of MS risk

Merck's Gardasil HPV vaccine--FierceBiotech file photo
Merck's Gardasil

Good news for Merck: According to a new study, its cash cow vaccine, HPV-blocker Gardasil, isn't linked to an increased risk of multiple sclerosis--or any other similar CNS diseases, for that matter.

In a study published Tuesday in JAMA, researchers looked through medical records of all Danish and Swedish girls and women aged 10 to 44 from October 2006 to December 2012--a population of 3.9 million.

Among the 790,000 who had received Gardasil, the rate of multiple sclerosis and other demyelinating CNS conditions was actually lower than it was in the unvaccinated group: Multiple sclerosis, for one, occurred in 6 of every 100,000 Gardasil recipients per year, compared with 21.5 of every 100,000 unvaccinated people per year, Forbes reports.

It's a win for Merck ($MRK) and partner Sanofi ($SNY), which helps hawk Gardasil through the companies' joint venture, Sanofi Pasteur MSD. And it couldn't have come at a better time for the pharma giants, which only just won approval for a 9-valent version of the vaccine that offers expanded protection. Analysts expect the successor shot to break the blockbuster barrier, though it'll cannibalize sales of original Gardasil--which raked in a $2.17 billion global 2013 haul--in the process.

But as the companies know well by now, study data doesn't always help put consumers' vaccine fears to rest. Gardasil helps ward off a serious cervical cancer threat, but uptake has been inhibited by unfounded side-effect concerns and worries that the vaccine encourages risky sexual behavior--despite evidence that debunks those myths. Last summer, the CDC found that only 57% of adolescent girls and 35% of adolescent boys received one or more doses of HPV vaccine in 2013--rates that fall far behind the 86% of children in the same age group that received the tetanus, diphtheria, and pertussis vaccine.

- get more from Forbes
- read the JAMA abstract

Special Reports: The top 5 vaccine makers by 2013 revenue - Merck | Top 10 best-selling vaccines of 2013