Tag: smallpox vaccine

Pandora Report 05.17.15

by juliadhomstad, posted in Pandora Report

Yowza! That’s another semester in the books for the GMU Biodefense students. Please excuse the sparse activity on the blog, but with the semester over, things should be getting back to normal.

This weekend we have a updates on Ebola and the bird flu outbreak in the U.S., plus other stories you may have missed.

Have a great week, (enjoy the Mad Men finale!) and see you back here next weekend!

Ebola is (still) living in an American doctor’s eye

As an update, Liberia has (finally) been declared Ebola free, the number of cases in Guinea continue to rise due to transmissions at funerals, and those in Sierra Leone are dying less from Ebola than from other diseases due to the collapse of the healthcare system. It’s been over a year and we are still learning things about Ebola and its persistence on hospital surfaces, sexual fluids, and now, according to a study in the New England Journal of Medicine, the eye. WHO volunteer Ian Crozier was diagnosed in Sierra Leone and transported to Emory University where he was treated. Months later he returned to the hospital with symptoms like blurred vision and acute pain in his left eye. The cause? Ebola.

The Washington Post—“Ebola may have found refuge in patients’ eyes because, researchers said, the eye is walled off from the immune system. As the New York Times put it: “The barriers are not fully understood, but they include tightly packed cells in minute blood vessels that keep out certain cells and molecules, along with unique biological properties that inhibit the immune system.” This phenomenon is called “immune privilege” — and it means the eye can harbor viruses.”

America’s $45 Billion Poultry Industry Has a (Really) Bad Case of Bird Flu

The title says it all, frankly. Since early December 2014 three strains of highly pathogenic avian influenza have been circulating in North America. A state of emergency has been declared in Iowa (one of the hardest hit states) and over 21 million birds have been killed to contain and prevent the spread of the virus. Beyond the culling of birds, the outbreak is having an affect on business—China, South Korea, and Mexico have banned imports of U.S. poultry (to protect their own industries.)

The Motley Fool—“Falling exports could hurt farmers, but it could also help to offset domestic price increases from less supply. Although, with tens of millions of bird deaths and no end in sight to the pandemic, domestic food prices could be the largest casualty in the end.”

Stories You May Have Missed

 

Image Credit: 8thstar

Pandora Report 8.31.14

by juliadhomstad, posted in Pandora Report

Fall classes at George Mason have already started and this Labor Day weekend marks the official end of summer. This week, we have stories covering a wide range of topics—an Ebola update (of course), a fascinating article on vaccinia infections acquired through shaving, Haj precautions, and the ISIS “laptop of doom.”

Best wishes for a safe and enjoyable holiday!

Ebola Virus Outbreak Could Hit 20,000 Within Nine Months, Warns WHO

There were many stories this week covering the continuing Ebola outbreak in West Africa. Senegal saw its first (imported) case of the virus this week and has banned flights to and from the affected countries while shutting its land border with Guinea and Nigeria saw its first death outside of the capital city of Lagos. In the Democratic Republic of Congo, where Ebola first emerged in 1976, there have been reported cases of a hemorrhagic gastroenteritis similar to Ebola. I read conflicting accounts this week of the “patient zero” for the Ebola outbreak—a young boy or an older traditional healer. There were reports of some U.S. universities screening students from West Africa for Ebola. There was coverage of a Toronto medical isolation unit ready for patients and information about GlaxoSmithKline’s experimental ebola vaccine which would be tested on humans in the next few weeks.

All of this news came among World Health Organization estimates that this West African outbreak could affect 20,000 people over the next nine months and that half a billion dollars would be needed to stop the spread of the disease.

The Wall Street Journal—“The WHO program will likely cost around $490 million and require contributions from national governments, some U.N. and non-governmental agencies, as well as humanitarian organizations, it said.”

First Reported Spread of Vaccinia Virus Through Shaving After Contact Transmission

This week, reports in the August issue of Medical Surveillance Monthly Report from the Armed Forces Health Surveillance Center covered vaccinia virus infection—the virus used for smallpox vaccinations—within the U.S. Air Force. The infections in the report occurred in June 2014, and affected four individuals.

Infection Control Today—“Over the past decade, most cases of contact vaccinia (i.e., spread of the virus from a vaccinated person to an unvaccinated person) have been traced to U.S. service members, who comprise the largest segment of the population vaccinated against smallpox. Most involve women or children who live in the same household and/or share a bed with a vaccinee or with a vaccinee’s contact. Of adult female cases, most are described as spouses or intimate partners of vaccinees or secondary contacts. Of adult male cases, most involve some type of recreational activity with physical contact, such as wrestling, grappling, sparring, football, or basketball. Household interactions (e.g., sharing towels or clothing) and “unspecified contact” are also implicated.”

Government to Keep Haj Infection-Free 

This week, the Saudi Arabian Ministry of Health announced mandatory measures for Haj and Umrah pilgrims coming from countries with active outbreaks or high rates of infectious diseases. The Health Ministry sent information to embassies outlining health requirements for those seeking pilgrim visas.

Arab News—“‘Although we do not issue Haj visas for pilgrims coming from endemic countries, we will still be monitoring pilgrims coming from other African countries for Ebola symptoms,’ said [Sami] Badawood [Jeddah Health Affairs director.]

He said the ministry would also focus on diseases such as yellow fever, meningitis, seasonal influenza, polio and food poisoning.”

Is the ISIS Laptop of Doom an Operational Threat?

Discovery of a laptop, which has been linked to ISIS, raises new questions about the organization’s plans relating to use of WMD—specifically chemical or biological weapons. Over 35,000 files on the laptop are being examined and has offered new insight into ISIS and their WMD aspirations.

Foreign Policy—“Most troubling is a document that discusses how to weaponize bubonic plague. But turning that knowledge into a working weapon requires particular expertise, and it’s not clear that the Islamic State has it.”

 

Image Credit: Wikimedia Commons

Reemergence of smallpox: A greater threat now than ever before

by juliadhomstad, posted in News

By Chris Healey

In the event of a resurgence of smallpox, treatment and containment would be exacerbated by illnesses and medical practices not present when the virus was eliminated.

Smallpox was one of the most significant diseases in human history. Although it was first distinguished from measles in China around 340 AD, evidence of the disease has been found on the remains of Egyptian mummies entombed over a thousand years earlier.

Smallpox is caused by Variola major, a virus in the Orthopoxvirus genus. The illness is known for causing characteristic pustules, severe symptoms and debilitating morbidity. Mortality rates exceeding 30% have been reported. The disease is almost always fatal in immunocompromised individuals.

Efforts to confer immunity against smallpox have been practiced for centuries. A technique called variolation, which involved inoculation with material from smallpox pustules, was used as far back as 1000 AD.

Due to the conserved nature of Orthopoxvirus, immunity to a wide range of viruses within the genus can be conferred after infection with a virus within the same genus. In 1796, Edward Jenner discovered inoculation with cowpox conferred immunity to smallpox. He called the technique vaccination, from the Latin vacca for cow. Vaccination results in less adverse effects and fatalities than variolation, making it the preferred method of conferring smallpox immunity.

Today, vaccinia virus is used in lieu of cowpox virus to confer immunity. Vaccinia virus creates a localized lesion that disappears over time in most individuals.

Persistent vaccination practices lead to the elimination of smallpox from most industrialized countries by the 1950s. In 1966, the World Health Assembly voted to fund an aggressive worldwide vaccination campaign to whittle away remaining pockets of the illness. After a successful campaign, the World Health Organization declared smallpox eradicated on December 9, 1979. The organization issued a recommendation for the cessation of smallpox vaccination in 1980.

Although smallpox is not a public health threat, it still exists. Stockpiles of the virus are maintained at the headquarters of the Centers for Disease Control in Atlanta and at a biotechnology institute in Novosibirsk, Russia.

Reintroduction of smallpox to the population would be devastating. Several immunologically-naïve generations are present. Other than those who received smallpox vaccines through military or specialized research positions, the entire population is almost completely unprotected.

Immunocompromised individuals who receive a vaccine utilizing a virus capable of self-replication, also known as a replication-competent vaccine, have a risk of developing a condition called progressive vaccinia. It is an extremely debilitating condition with no cure and a 90% fatality rate.

Dryvax, the vaccine used to eliminate smallpox, was replication-competent. Progressive vaccinia was reported as a rare adverse reaction when smallpox vaccines were administered during eradication efforts. Although Dryvax is no longer used, another replication-competent vaccine, ACAM2000, has taken its place. If ACAM2000 is administered to the general population today, far more cases of progressive vaccinia are expected to occur.

HIV and immunosuppression drugs are two modern factors contributing to decreased immune function. The World Health Organization estimates 35.3 million people in the world are living with HIV—1.1 million of those in the United States. Immune suppression associated with the illness would make smallpox vaccination undesirable, and smallpox infection fatal. HIV was not a factor during eradication efforts. Individuals with HIV would be at great risk in the event of smallpox reemergence.

Many modern drugs dampen the immune system to alleviate a range of conditions and symptoms, from hay fever and asthma to anti-rejection drugs for transplant recipients. Immunosuppression drugs have become commonplace. Those drugs did not play a significant role during eradication efforts because they were very expensive and uncommon. In the event of a re-emergence, smallpox would likely exploit those taking immunosuppression drugs. Furthermore, immunosuppression drugs dramatically increase the chance of developing progressive vaccinia following smallpox vaccine administration.

There is, however, a vaccine alternative for immunocompromised individuals. Imvamune is a replication-incompetent vaccine produced by Bavarian Nordic. Replication-incompetent vaccines deliver a virus incapable of replication, meaning it cannot cause progressive vaccinia. Unfortunately, there is no way to test the vaccine’s ability to confer smallpox immunity. Replication-incompetent vaccines are generally considered by health experts to be less effective at conferring immunity than replication-competent alternatives.

It is for these reasons that the re-emergence of smallpox would deal a catastrophic blow to the wellbeing of individuals around the world and therefore every effort must be made to prevent the return of smallpox.