Bivalent oral polio vaccine produces better immune response than more commonly used trivalent vaccine, study says

The bivalent oral polio vaccine (bOPV) was found to induce a "significantly higher immune response" than the existing trivalent oral polio vaccine (tOPV), according to a study published on Tuesday in the journal Lancet, Reuters reports (Kelland, 10/26).

The bOPV produced a "similar immune response to the monovalent vaccine," according to a Lancet press release. Though the tOPV targets all polio strains, bOPV targets types 1 and 3, which persist in "parts of the polio-endemic countries of Afghanistan, Pakistan, India, and Nigeria," the press release states (10/25).

For the study, experts from the WHO and India gave either the bOPV or existing vaccines to 830 newborn babies at three medical centers in India, Agence France-Presse reports (10/26). Vaccines were given after birth and then 30 days later, Reuters writes. "Blood samples were taken before vaccination and after the first and second doses to measure rises in antibody levels," the news service reports (10/26). Researchers found that after two doses of either the mOPV1 or bOPV, "approximately 90% of babies developed immunity to type 1 virus, compared with 63% after tOPV. The second dose induced immunity to type 3 virus in 84% of recipients of mOPV3, 74% of bOPV, and 52% of tOPV," the press release notes (10/25).

The WHO's Roland Sutter, who led the study, said, "This (new) vaccine could get us over the top and get us to the finish line for eradication," the BBC reports. "The dramatic drop in the number of polio cases in India and Nigeria is attributable to the new vaccine and better coverage during immunization campaigns," he said (Lichtarowicz, 10/25). The study received most of its funding from the GAVI Alliance, the press release states (10/25).

In a related Lancet commentary, "Nigel Crawford and Jim Buttery from the Murdoch Children's Research Institute in Melbourne, Australia, said the potential effectiveness of the bivalent vaccine was already being shown in India where it is being used on a large scale. Latest polo data show just 32 cases so far this year, compared with 260 in 2009, they wrote," according to Reuters. They also pointed out that the global economic situation has led to a significant funding shortfall, which could threaten the goal of polio eradication.

"'The plan of action for polio eradication - with bOPV as the centrepiece - is only 50 percent funded for 2010-12,' they wrote. They described the potential of the new bivalent vaccine as 'an important step forward' but said 'a final concerted effort, both locally and worldwide, is required' to succeed in finally eradicating the virus," according to Reuters (10/26).

U.N. Foundation Leaders Note Polio Vaccine Partnership Successes In Nigeria

U.N. Foundation Founder and Chairman Ted Turner was in Nigeria on Monday, noting the country's success in efforts to eliminate polio, the AFP reports (10/25).

Turner is in the country along with U.N. Foundation President Timothy Wirth and U.N. Foundation Board Member Andrew Young "to meet with government and community leaders to learn firsthand about the power of public-private partnerships aimed at improving children's health," according to a U.N. Foundation press release. The visit comes at the end of a week-long board meeting in Africa (10/25).

"The foundation said in a statement that recent progress in Nigeria is proof that vaccines are key to eradicating polio and reducing measles worldwide. 'Working together, I know we can finish the job on polio,' Turner said after talks with key government officials and traditional rulers, particularly in northern Nigeria, where the threat is more pronounced," AFP writes (10/25).

Turner said the public-private partnerships that have been instrumental in fighting polio in Nigeria could be used as a model to deal with other health challenges. "With support from leaders like the Sultan of Sokoto, we are on the verge of achieving the first great humanitarian victory of the 21st century - the complete elimination of a disease that once afflicted millions. By building on the success of partnerships like these, we can eliminate measles and protect children from other vaccine-preventable diseases to achieve the Millennium Development Goals (MDGs)," he said, the press release notes. "Last year Nigeria reduced cases of polio by 98 percent with only eight cases confirmed in 2010, as compared to nearly 400 in the fall of 2009," according to the release (10/25).