Health Experts Gear Up Global Vaccine Plan

A Guatemalan volunteer administers a vaccine to a Mayan child to protect her from five diseases. UNICEF says vaccines save 2 million to 3 million children’s lives each year.

Washington — Hundreds of millions of people worldwide get sexually transmitted infections (STIs) each year, and in many cases, their chances of becoming infected with HIV increase as a consequence. An original infection could also escalate into other health problems related to childbirth, infertility, difficult pregnancy or other conditions.

U.S. and international health experts are joining forces to chart a scientific agenda and build political will and resources to develop vaccines that could prevent STIs that have some of the most difficult long-term consequences: herpes simplex virus (HSV), chlamydia, gonorrhea, syphilis and trichomoniasis, an infection of the urogenital tract.

“Widespread immunization with safe and effective vaccines could revolutionize the way we tackle STIs,” said Dr. Jean-Marie Okwo-Bele, director of immunization, vaccines and biologicals at the World Health Organization (WHO).

In a special edition of the publication Vaccine, this coalition of specialists from WHO, the National Institute of Allergy and Infectious Diseases (NIAID) and other European agencies outlines a “road map” — a systematic plan — to STI vaccine development.

The road map emerges from a “technical consultation” among scientific experts convened by WHO in April 2013. They looked at the current state of development for STI vaccines and sketched out ways to ensure their future availability.

The effort stems from the Global Vaccine Action Plan endorsed by the more than 190 member nations of the World Health Assembly in 2012. The plan sets a 2020 goal to bring out new and improved vaccines and related technologies. The global plan is also devoted to strengthening routine immunization and improving control of diseases well-known to be preventable with vigorous immunization campaigns, notably polio.

Experts participating in the consultation say work in basic science, epidemiology, clinical research and public health planning is required before laboratories can create useful vaccines suitable for broad public use. The effort requires better data on the prevalence and incidence of these diseases, especially as they occur in low- and middle-income countries, according to the plan summary published in Vaccine.

Science also needs to develop a better understanding of “the burden of infection-related disease sequelae,” that is, the long-term health consequences and complications that result from STIs. All five of the targeted STIs are associated with increased rates of transmission and acquisition of HIV, for example, but medical science needs more information about how readily and frequently these occur. Infertility, ectopic pregnancy, preterm labor and other pregnancy complications can be related to various STIs. The plan also calls for better data on the progression of these problems and how to diagnose them.

STI complications and consequences have a cost beyond the health of an individual, so the plan will also aim to learn more about the personal and social costs of these health problems: how they affect individual productivity, family incomes or community vitality.

The thorough, painstaking basic science research required to produce an effective vaccine is also a huge task ahead, according to the road map summary, involving many steps. Identifying just the right substance that will trigger the body’s immune response — the antigen — is a huge step, and one that will be different for each of the targeted STIs.

Conducting the basic field studies — first in animals and then among real people — is another critical process in vaccine development. Then researchers still have to evaluate whether a particular vaccine candidate not only works against the disease, but whether it can actually work in the community, which involves factors like cost and delivery.

The initiative is rooted in the principle that overcoming those obstacles is “an achievable goal,” according to an editorial in Vaccine.

“Two existing vaccines, against hepatitis B virus and human papillomavirus (HPV) have shown that it is possible to develop safe and effective vaccines against STIs,” the editorial said.

With an estimated 1 million or more people contracting a new STI every day, the technical consultation group concludes it is vital that new measures be found to prevent these diseases and their “often devastating reproductive health consequences.”

Vaccine development and distribution have long been U.S. goals in improving public health, with lifesaving results. The U.S. Centers for Disease Control and Prevention reports that a global initiative to broaden availability of the measles-rubella vaccine has averted 10 million deaths in a decade and reduced child deaths by 71 percent.