Oct. 21 (Bloomberg) -- -- Merck & Co.’s Gardasil vaccine, used to protect girls from a virus linked to cervical cancer, shouldn’t be given routinely to boys, a U.S. advisory panel said.

The committee on immunization of the Centers for Disease Control and Prevention voted today that Gardasil should be optional for boys rather than part of the approved childhood vaccination schedule. The shot is endorsed for routine use in girls 11 to 12 years old. It will be covered for boys and girls under a U.S. program for children who are uninsured or on Medicaid.

The U.S. Food and Drug Administration on Oct. 16 cleared the vaccine for males, ages 9 to 26, to prevent genital warts. Gardasil protects against a sexually transmitted infection called human papillomavirus, or HPV, that can lead to cervical cancer in women and to genital warts and cancer of the penis and anus in men. The benefits didn’t justify the cost of administering the vaccine to all boys, the panel said.

“Nobody knows what the private insurance plans will do,” Harrell Chesson, a CDC economist, told the panel in Atlanta. “They may not distinguish between boys and girls, but we just don’t know.”

Decisions by the Advisory Committee on Immunization Practices are regularly adopted by the U.S. government.

Merck Response

“Approximately 75-80 percent of males and females will acquire one or more types of HPV in their lives and HPV-related diseases cause significant personal and public health burden for both men and women,” said a Merck spokeswoman, Pam Eisele, in an e-mail. “As such, we believe there is value in vaccinating both young men and women with Gardasil to help protect them from certain diseases caused by HPV.”

The committee also voted today to include GlaxoSmithKline Plc’s competing vaccine, Cervarix, on the U.S. list of recommended vaccines for girls. Cervarix was approved Oct. 16 in the U.S. to prevent cervical cancer in females ages 10 to 25. Safety concerns contributed to a regulatory delay of Cervarix in 2007, giving Merck a head start.

The CDC’s recommendation on Glaxo’s Cervarix, once adopted, will tell doctors that both vaccines prevents cervical cancer, while Gardasil also protects against genital warts and cancer of the vagina and vulva. Language saying the panel had no preference for either vaccine was stricken after some members said wart protection makes Gardasil a better shot.

Merck, based in Whitehouse Station, New Jersey, fell $1.04, or 3.1 percent, to $32.68 at 4:15 p.m. in New York Stock Exchange composite trading. It was the biggest decline in seven weeks. American depositary receipts for London-based Glaxo declined 2 cents to $41.59.

‘Permissive Use’

The CDC panel recommendation of “permissive use” for boys, where vaccination is left to a doctor’s discretion, may add $200 million to $300 million in annual Gardasil sales by 2015, Leerink Swann’s Fernandez wrote in a note to clients on Oct. 19. Gardasil sales fell 5 percent last year to $1.4 billion, the company has said.

It would cost more than $290,000 to vaccinate enough boys and girls to save one year of life, compared with about $40,000 when vaccinating girls alone, according to a study by Harvard University School of Public Health researchers, released Oct. 9 in the British Medical Journal.

QUALY Analysis

Any vaccine that costs less than $100,000 per year saved, also known as Quality-Adjusted Life Year, or QUALY, is considered “a good deal,” said William Schaffner, chairman of the department of preventive medicine at Vanderbilt University in Nashville, Tennessee. The QUALY model increases the numbers of years saved to include some benefit for living without nuisance diseases, such as warts. Some vaccines are approved even without reaching the $100,000 threshold, said Schaffner, who is not a member of the working group that advised the panel.

Merck’s study found it would cost about $50,000 for both boys and girls. The Harvard and Merck studies used different assumptions to reach their conclusions. The Harvard study evaluated the cost of vaccinating 12-year-olds, while Merck studied vaccinating those ages 9 to 26. The Harvard study assumed a higher cost of $500 per vaccinated child with 75 percent effectiveness of the vaccine, while Merck’s study used a cost of $400 with 100 percent efficacy.

Cost Concerns

“Over the last five and six years, cost-benefit analyses have played a larger and larger role in vaccine debates,” Shaffner said. “The committee has gone back and forth and really agonized about that.”

In a Merck-funded study released last year, researchers gave 4,065 boys and men ages 16 to 26 the vaccine or a placebo, then tracked them for signs of infection with HPV. After about 30 months, three men getting Gardasil developed genital warts and none had pre-cancerous growths linked to the HPV virus, compared with 28 cases of warts and three pre-cancerous lesions in the placebo group.

Merck will expand a patient rebate and dose replacement program to help cover the cost of the vaccine for 19- to 26- year-old men without health insurance and those with private insurance with partial or no coverage for the shots, according to a company statement.

Gardasil protects against four of the most common of 40 strains that can infect the genital area, while Cervarix protects against two. More than 1 million cases of genital lesions, which can lead to cancer, occur in men and women in the U.S. each year, and 30 million cases occur worldwide, according to Merck.

Multiple Doses

Gardasil and Cervarix are given in three doses during a six-month period to trigger immune responses that help protect against the two HPV strains responsible for most U.S. cervical cancer cases.

Glaxo faces a challenge in winning doctors’ and parents’ support for Cervarix because of Gardasil’s added protection, and Cervarix is unlikely to gain more than 20 percent of the U.S. market, according to Leerink’s Fernandez. Cervarix is cleared in 100 countries and had sales of 125 million pounds ($232 million) last year, about one-sixth as much as Gardasil.

While 20 million Americans are infected with HPV, most will be able to fight off the infection naturally, according to the National Cancer Institute. About 1 percent of sexually active men in the U.S. will develop genital warts from HPV, the CDC said. Gardasil is approved for males in 40 countries worldwide.

The most common side effect is fainting after getting the injection, followed by irritation around the skin site and dizziness, according to a government analysis of side-effect reports. For every 100,000 shots, eight patients will faint, seven will have reactions at the area of the injection and seven will become dizzy, according to a study published in the Journal of the American Medical Association and conducted by the CDC.

To contact the reporters on this story: Tom Randall in New York at trandall6@bloomberg.net; Shannon Pettypiece at spettypiece@bloomberg.net.

Last Updated: October 21, 2009 17:36 EDT