Vaccine Experts Cite Progress On Measles, Rubella
Transmission of rubella is now limited to one country in the Americas, and measles now occurs only when cases are imported from outside the Western Hemisphere, vaccination experts reported today at a special four-day meeting on vaccine-preventable diseases.
Participants also urged countries to prepare to administer pandemic influenza vaccine, which is expected to be in limited supply during initial production.
The Pan American Health Organization's Technical Advisory Group on Vaccine Preventable Diseases organized this week's meeting to discuss "Immunization: Prioritizing Vulnerable Populations." Some 200 experts from throughout the Americas are reviewing achievements, the unfinished vaccine agenda, future challenges of new vaccines, and ways to accelerate progress against vaccine-preventable diseases.
"Considering that pandemic (H1N1) vaccine supply will be limited in the beginning stages of production, Member States will need to prioritize risk groups, a process that involves scientific, logistical, ethical, moral, cultural and legal considerations," said Dr. Cuauhtemoc Ruiz, PAHO's senior advisor on immunization.
PAHO Assistant Director Dr. Socorro Gross cited World Health Organization (WHO) estimates that 2.4 billion doses of pandemic (H1N1) vaccine will likely be available in six months, and 4.9 billion doses after one year of production. She noted, however, that these figures may change and that large quantities of vaccines have already been committed through advanced-purchase agreements. Maintaining good surveillance and identifying risk groups that should be vaccinated first, such as health workers, will be critical in the coming months, she said, adding that PAHO is studying ways to expand vaccine production to help ensure equity and access for all.
As part of efforts to help its member countries confront the H1N1 pandemic, PAHO has developed and distributed a Regional Vaccination Plan for Pandemic Vaccine, which includes plans to strengthen seasonal influenza vaccination. PAHO is urging countries to set their own vaccination strategies and their own priority target groups.
"While there is little evidence that seasonal influenza vaccines confer cross-protection against pandemic (H1N1), strengthening vaccination with the seasonal vaccine is essential to reduce the disease burden and to prevent the co-circulation of seasonal and pandemic (H1N1) influenza strains," Dr. Ruiz noted.
Dr. Ciro de Quadros, chairman of the technical advisory group, noted that the Americas interrupted endemic measles virus circulation in 2002 and as of 2009 has limited endemic rubella transmission to only one country by pioneering and implementing successful measles and rubella vaccination strategies.
By 2008, all the Region's countries had introduced measles-rubella (MR) vaccine into their routine immunization programs, protecting an estimated 440 million from measles and rubella, Dr. de Quadros said. However, many challenges remain, including the ongoing risk of importations and secondary spread, preventing and responding to outbreaks, and ensuring quality surveillance and laboratory capacity to provide the evidence base for elimination efforts.
Both measles and rubella remain endemic in all WHO Regions outside the Americas. Because of the large numbers of international travelers visiting the Americas each year and the ease of transmission of both measles and rubella via the respiratory route, the risk of importations into the Americas remains high. In the first three months of 2009, 11 new measles outbreaks were reported worldwide, including four in countries in the Americas resulting from importations.
Members of the technical group and other experts presented three publications and a certificate of appreciation to Costa Rican President Oscar Arias in a ceremony at the National Theater on the meeting's first day. President Arias praised the work of the Pan American Health Organization in promoting the elimination of vaccine-preventable diseases, noting that smallpox now exists only in history books.
"Words like measles and rubella will likely only exist in history books for our grandchildren, due to the work of brilliant scientists and responsible politicians," Arias said.