Vaccine Briefs

Economy Threatens World Progress on Immunization

The third edition of the State of the World’s Vaccines and Immunization brought some good news about efforts toward immunizing children against vaccine-preventable diseases and the development of new vaccines, but also some dire warnings about how the global economic downturn might impede progress in immunization programs.

The report, issued in October by the World Bank, the World Health Organization (WHO), and the United Nations Children’s Fund (UNICEF), noted that there are now 106 million children receiving the required three doses of DPT (diphtheria-pertussis-tetanus) vaccine before their first birthday—a 74% increase in coverage since 2000. Despite this progress, 24 million children a year still fail to receive even a single dose of the DPT vaccine—a gap global health authorities fear will only widen if donor countries fail to sustain investments in immunization programs, particularly in developing countries. The global economic downturn is causing concern that the United Nations' Millennium Development Goal to reduce deaths among children under age five by 66% between 1990 and 2015 will not be met if countries are forced to curtail their immunization campaigns.

“This report is really a call to action aimed at everyone,” said Graeme Wheeler, managing director of operations at the World Bank, at an October 21 report launch in Washington, D.C. Wheeler said an estimated US$1 billion is needed annually to ensure that new and existing vaccines will be delivered to all children in 72 of the world’s poorest countries, and that a failure to continue to support campaigns will cause many diseases to come roaring back. “We need to stick with it,” he said.

Polio illustrates the power of global immunization campaigns particularly well. The disease, which caused widespread panic in industrialized countries during the 1940s and 1950s and until recently was endemic in many developing countries, has ebbed, largely due to immunization campaigns. There were just 1,247 new polio cases worldwide this year, according to the WHO, and there are now only four countries where polio is still endemic: Nigeria, Pakistan, India, and Afghanistan.

Along with immunizing children against DPT, MMR (measles, mumps, and rubella), and polio, there is also a growing stable of new vaccines that protect against rotavirus, meningitis, the highly pathogenic H5N1 avian influenza virus, pneumococcal disease, and certain strains of the human papillomavirus that can lead to the development of cervical cancer. The WHO estimates that pneumococcal disease and rotavirus infection together account for 1.3 million deaths in children annually—mostly in developing countries.

The report noted that continued investments will also be needed to accelerate the development of vaccines against tuberculosis, AIDS, and malaria, which are responsible for more than four million deaths a year, mainly in developing countries. The report estimates the cost of developing a new vaccine to be $500 million. There are currently about 80 vaccines in the late stages of clinical testing—40 of them are aimed at diseases for which a vaccine does not yet exist. Of those, the malaria vaccine candidate RTS,S/AS01 being developed by GlaxoSmithKline Biologicals, which is being tested in a recently launched Phase III trial in Africa, was cited as a high-impact vaccine that was the furthest along in clinical testing. —Regina McEnery

WHO Meeting to Evaluate Test-and-Treat Strategy

Nearly a year after a quintet of researchers from the World Health Organization (WHO) published an article in The Lancet describing the results of a mathematical model that predicted that a combination of annual HIV testing and immediate antiretroviral (ARV) treatment could potentially end the AIDS epidemic in 50 years, scientists, public health officials, and community activists gathered from November 2-4 to talk exclusively about the strategy dubbed test and treat (1). The widely publicized Lancet study used South Africa to model a generalized HIV epidemic (seeTest and Treat on Trial, IAVI Report, July-Aug. 2009).

The WHO convened the meeting in Geneva, Switzerland, to stimulate discussion about the ethical implications, acceptability, and feasibility of implementing the test and treat approach in various populations. Researchers considered some of the ways to study a strategy that looks promising based on mathematical models, but which has not yet been subjected to the rigors of a randomized, controlled clinical trial.

The experts who gathered in Geneva included Julio Montaner, president of the International AIDS Society, who is a vocal advocate of early initiation of ARV treatment and has been studying the impact that expansion of ARVs has had on lowering community viral load and HIV incidence in Vancouver, British Columbia. Community viral load reflects the mean viral load of a group of HIV-infected individuals. Montaner said a study that looked at the effect of expanding ARV treatment from 3,500 HIV-infected individuals to 5,000 in a community in Vancouver appears to have had an impact on transmission. “All I am prepared to say right now is that new HIV infection rates are going down,” said Montaner. There are about 13,000 HIV-infected individuals in British Columbia who are eligible for ARVs.

“There are huge opportunities to address some very important questions related to the effectiveness of ARVs, both in terms of morbidity and mortality outcomes as well as HIV transmission,” said Montaner. “Those opportunities will become even greater with the anticipated release of new WHO guidelines,” he added. According to Montaner, the WHO is expected to increase its benchmark for initiating ARV therapy from 200 CD4+ T cells to 350 CD4+ T cells later this year.

US researchers are hoping to launch a pilot study next spring to evaluate the feasibility of implementing test and treat in Washington, D.C., which has the highest prevalence of HIV in the country, and the Bronx in New York City, which has the highest AIDS death rate of the city’s five boroughs due to the fact that so many HIV-infected individuals are diagnosed late. The three-year study will occur in high-risk communities where poverty, racial discrimination, AIDS stigma, distrust of doctors, and other factors can be barriers to accessing medical care. Wafaa El-Sadr, the director of the Center for Infectious Disease Epidemiologic Research at Columbia University’s Mailman School of Public Health, will be heading up the pilot study, which is being funded by the US National Institute of Allergy and Infectious Diseases (NIAID) and reflects a collaborative effort between NIAID, the US Centers for Disease Control and Prevention, and local health departments in the two cities.

El-Sadr said the goals of the study are to determine the best way to link HIV testing and treatment programs, to retain HIV-infected individuals in treatment programs, and to ensure individuals adhere to their daily ARV regimens.

“What I got from the [WHO] meeting was a collective commitment of the importance of continuing to expand access to treatment,” said El-Sadr. “Only about 40% of people who need treatment today can obtain it. We have a long way to go.”

Mark Harrington, an activist who heads the Treatment Action Group in New York City, said he left the WHO meeting more optimistic about the approach. At the very least, Harrington said, test and treat may provide better linkage between prevention and treatment. “Care and treatment and prevention need to be done altogether.” —Regina McEnery

1. Lancet 373, 48, 2009