Abstract Science: Infectious Diseases
Hepatitis B's global footprint, complications from MERS, and a vaccine paradox. This week in Abstract Science.
(Wired Science, 7/27/2015, Sarah Zhang)
Since Middle Eastern Respiratory Syndrome (MERS) emerged three years ago not a single drug has been developed to treat or cure this relatively rare virus that kills a third of its victims. There is cause for optimism on the therapeutic antibody front, however. A study this week in the Proceedings of the National Academy of Sciences found that antibodies from the blood of a MERS survivor can treat the disease in mice. That's good news. The bad news is that clinical trials to prove the antibody is both safe and effective in humans could take up to a decade. The antibodies will have to be tested in primates and eventually humans and the outcomes are far from certain. A number of research groups have identified anti-MERS antibodies, but the study published today in PNAS takes an antibody from the blood of an actual patient. Researchers at the US National Institutes of Health are also working on a vaccine candidate against MERS. While a vaccine could be used to prevent MERS, it also raises the question of when, where and whom to vaccinate.
(The Washington Post, 7/27/2015, Rachel Feltman)
A study published this week in PLoS Biology found that a vaccine given to chickens to prevent a common herpes virus known as Marek's disease appeared to make the pathogen more pathogenic. While the findings would appear to have little bearing on human vaccinations—the virus only occurs in chickens—scientists are concerned that the data will fuel an anti-vaccine movement particularly strong in the US and the UK. "It's important not to interpret this study as an argument against vaccination of our children against flu or any other disease," Peter Openshaw, the president of the British Society for Immunology, told The Washington Post. The study's lead author, Andrew Read, head of the avian viral diseases program at Penn State University, doesn't know if the imperfect vaccine caused more virulent strains of the illness to develop. And for now, leaky vaccines—those that don't make their host totally immune to disease yet incapable of passing on to others—are a problem confined to the treatment of farm animals. But there are concerns that as scientists push to develop human vaccines against big, intractable viruses—such as HIV or tuberculosis—they will need to keep the issues of leaky vaccines in mind. Other scientists say while the findings are convincing for Marek's disease, one should be careful about drawing general conclusions about the impact of vaccines on preventing and controlling infectious diseases.
An international study funded by the World Health Organization shines a bright light on how often hepatitis B infections occur in different countries and how many people in the general population are affected. The findings, published in The Lancet, found huge disparities in the prevalence of this chronic vaccine-preventable liver disease. While hepatitis B infect only .01% of people in some countries over 20% are infected in other countries, namely parts of Africa and lower-income areas in other geographic regions. Analysis of prevalence rates also found global changes between 1958-1989 and 1990-2013, which were likely due to a recommendation in 1992 by the WHO to vaccinate against hepatitis B. That the problem still persists in some countries, despite an effective vaccine and treatment options, shows that hepatitis B virus infections continue to be an important global health problem in countries with poor public health systems and large numbers of infectious diseases.
—Compiled by Michael Migliaccio, Communications Coordinator with Charles River Laboratories