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John Jesitus is a medical writer based in Westminster, CO.
In the quest for new vaccines, developers must balance clinical promise with practical concerns, said Kenneth Tomecki, M.D., at the 70th annual meeting of the American Academy of Dermatology. "The future for vaccines is very encouraging," says Dr. Tomecki, vice chairman, department of dermatology, Cleveland Clinic.
San Diego - In the quest for new vaccines, developers must balance clinical promise with practical concerns, said Kenneth Tomecki, M.D., at the 70th annual meeting of the American Academy of Dermatology.
"The future for vaccines is very encouraging," says Dr. Tomecki, vice chairman, department of dermatology, Cleveland Clinic. Many available vaccines have proven helpful. Likewise, "There are currently available vaccines that can be used a little more often." Additionally, a host of vaccines under development one day could eradicate diseases ranging from typhoid to tuberculosis, he says. However, "A lot of work needs to be done, and most of it is limited by cost - the cost to go from phase 2 to phase 3 studies is enormous. Phase 3 studies are especially expensive," he says.
Tweaking existing vaccines
To enhance its efficacy and applicability, including for children, developers are conjugating the existing vaccine with a purified diphtheria toxoid and, in a separate project, with a conjugate developed by Novartis, he says.
"The Peda Typh Vi tetanus toxoid (Bio-Med) is already licensed and under phase 3 study," he explains, adding that this product and a competitor likely will reach the market in two to three years.
To that end, Bexsero (Novartis), a meningitis B vaccine built around four proteins (providing six formulations) is in phase 3 testing. Additionally, Pfizer is conducting phase 3 trials with a two-protein combination (MnB rLP2086/PF-05212366). Both of these vaccines will provide advantages over the currently available meningococcal vaccine, Dr. Tomecki says, "But we probably won't see them on the market for at least two years."
Regarding current pneumococcal vaccines, "The problem is, there are more than 90 serotypes; covering them all is extremely difficult," Dr. Tomecki says. Existing vaccines (Prevnar, Prevnar 13; Wyeth/Pfizer) protect against seven or 13 pneumococcal serotypes. GlaxoSmithKline is developing a decavalent conjugate vaccine (Synflorix), which could reach the U.S. market in four to six years, he adds.
Rotavirus vaccines are available, but they work only about half as well in developing nations versus developed nations, perhaps due to poor nutrition, genetics or co-infections in the former regions, Dr. Tomecki says. Phase 3 trials are in progress, evaluating a strategy of vaccinating children at birth with naturally attenuated bacteria called nursery strains.
Among streptococcal vaccines, "Most of the work is being done with the M protein," Dr. Tomecki says. "There is a decent 26-valent vaccine using this protein (developed by ID Biomedical) under investigation in phase 2 and 3 trials."