The Global Fool

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The Global Travels of Chikungunya Virus: Is it Coming to You?
Mar30

The Global Travels of Chikungunya Virus: Is it Coming to You?

By Roberta Attanasio Chikungunya virus is spreading fast — worldwide. First described during an outbreak in southern Tanzania in 1952, it caused sporadic illness in Africa and large urban outbreaks in Thailand and India in the 1960s and 1970s. As of now, it has been identified in over 60 countries in Asia, Africa, Europe and Americas. The virus, which causes fever and severe joint pain, is transmitted to humans by the bites of infected female mosquitoes, most commonly by Aedes aegypti and Aedes albopictus — two species that can also transmit other mosquito-borne viruses, including dengue. There is no vaccine and no specific treatment for the infection. Gemma Handy aptly describes the onset of the disease in an Antiguan patient: “The acute ache started in her ankles before quickly spreading through her body, crippling her muscles, pounding her joints and leaving her hands and feet severely swollen.” The patient said: “”I was fine when I went to bed, but when I woke up in the morning and tried to get up my ankles hurt so much I couldn’t stand. It was very scary. After that I started getting different pains all over my body. Soon my hands were so swollen I couldn’t hold anything.” Indeed, “chikungunya” derives from a word in the Kimakonde language, which is spoken by the Makonde, an ethnic group in southeast Tanzania and northern Mozambique — it means “to become contorted”, and describes the stooped appearance of sufferers with joint pain. Most patients recover fully, but in some cases joint pain may persist for several months, or years — and even become a cause of chronic pain and disability. In 2007, disease transmission was reported for the first time in a localized outbreak in north-eastern Italy. Outbreaks have since been recorded in France and Croatia. According to the Centers for Disease Control and Prevention (CDC), the first local transmission of Chikungunya virus in the Americas was identified in Caribbean countries and territories in late 2013 — local transmission means that mosquitoes in the area have been infected with the virus and are spreading it to people. Beginning in 2014, Chikungunya virus disease cases were reported among U.S. travelers returning from affected areas in the Americas and local transmission was identified in Florida, Puerto Rico, and the U.S. Virgin Islands. The current numbers of people infected with the virus within the Americas are staggering: the Pan-American Health Organization reports that, as of the end of February 2015, the initial handful of cases had exploded to 1,247,400 suspected and confirmed cases, affecting almost every country in the hemisphere. After the first locally acquired case of Chikungunya was reported...

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Sex Differences in the Immune Response to Vaccines
Feb11

Sex Differences in the Immune Response to Vaccines

By Roberta Attanasio Women and men respond differently to infectious microbes and vaccines – it is said, indeed, that the immune system of women is stronger than the immune system of men. Stronger or weaker, one thing is certain – men and women are not the same in terms of immune response. A few years ago, the journal Lancet Infectious Diseases published “ The Xs and Y of immune responses to viral vaccines” – a comprehensive article that clearly shows how the biological differences between sexes influence the immune response to vaccines, as for example the influenza, yellow fever and hepatitis vaccines. There are not many published studies on the same subject, though. The majority of scientists involved in vaccine research do not consider sex as a variable and, typically, vaccine trials are not designed to take into account the physiological differences that exist between men and women. If we had to take these differences into account, how would things change when vaccinating human populations? In the New York Times article “Do women need such big flu shots?” Op-Ed contributors Sabra Klein and Phyllis Greenberger provide an example related to one of the influenza vaccines: “Under the current guidelines, men and women are to get equal-sized doses of the H1N1 vaccine. Yet women’s bodies generate a stronger antibody response than men’s do, research shows, so less vaccine may be needed to immunize them. If we could give women a smaller dose, there would be more vaccine to go around. And we might also spare them the mild side effects that vaccines can cause, like pain at the injection site, inflammation and fever. All of these are more common in women than in men.” In 2010, the World Health Organization published “Sex, Gender and Influenza”, a report that “focuses on the different effects of seasonal epidemics, pandemics and localized outbreaks of influenza on males and females including pregnant women.” The report concludes that “significantly more research is required to gain a more complete understanding of the complex and varied effects of sex and gender on influenza infection and vaccination, and underscores the need to consider their interplay with any infectious disease of global concern.” However, there are still large gaps in our understanding of how sex differences influence the immune response to vaccines and not enough research is done to fill these gaps. May be, step by step, we’ll get there. Meanwhile, here is one of the steps – a new study found that high levels of testosterone make the immune response to the flu vaccine go south. The study – “Systems analysis of sex differences reveals an immunosuppressive role for...

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