News Scan for Aug 28, 2014

News brief

Vaccine coverage remained high in 2013 but pockets of concern continue

Vaccination coverage of young US children against all routinely recommended vaccines remained high and even increased for certain vaccines last year, according to data from the National Immunization Survey (NIS), published today in Morbidity Mortality Weekly Report (MMWR).

Increases in coverage rates for 2013 over 2012 were seen for rotavirus vaccine (73% vs 69%), for one or more doses of Hep (hepatitis) A vaccine (83% vs 82%), and for the Hep B birth dose (74% vs 72%). Coverage rates were stable, all remaining above 90%, in 2013 compared with 2012 for MMR (measles, mumps, rubella), polio, Hep B, and varicella vaccines. Less than 1% of children received no vaccines.

Three vaccine series that require a booster dose during a child's second year of life—DTaP (diphtheria, tetanus, pertussis), Hib (Haemophilus influenzae type b), and PCV (pneumococcal disease) had coverage rates that were unchanged in 2013.

Children living in poverty had lower coverage rates for the booster doses of all the vaccines just mentioned as well as for polio, rotavirus, and Hep B vaccine series. The MMWR report notes that free vaccines are available to families in need through the Vaccines for Children program.

Coverage varied greatly by geographic area. For example, vaccination with at least one dose of MMR ranged from 96% in New Hampshire to 86% in Colorado, Ohio, and West Virginia.

Nationally, MMR coverage was 92%, but 1 in 12 children did not receive the first dose on time, according to the report. The authors note that this leaves a sizable number of young children susceptible to measles, highlighting the importance of attention to the disease at a local level.

The "combined vaccine series" measurement, which assesses overall performance by means of the completion of immunization series for 11 diseases, ranged from a high of 82% in Rhode Island to a low of 57% in Arkansas.

The NIS, which has been conducted annually since 1994, is a random telephone survey of households with children aged 19 to 35 months of age. The 2013 estimates were based on 13,611 completed interviews where vaccination data were adequate.
Aug 29 MMWR NIS report
Aug 28 CDC press release on NIS report
NIS Web site
Vaccines for Children Web site

FDA puts Pfizer's candidate C difficile vaccine on fast track

An experimental Clostridium difficile vaccine made by Pfizer Inc. has received a "fast track" designation from the US Food and Drug Administration, which could speed its further development and licensing, the company announced today.

The vaccine, called PF-06425090, is designed to prevent C difficile–associated disease, which can include life-threatening diarrhea and pseudomembranous colitis, the company said. It is currently in phase 2 testing.

The fast-track approach is designed to facilitate the development and expedite the review of new drugs and vaccines intended to treat or prevent serious conditions and to address an unmet medical need, the Pfizer announcement noted.

C difficile is the most common cause of healthcare-associated infections and a common cause of diarrhea associated with antibiotic treatment, the company said.
Aug 28 Pfizer press release

Cholera vaccine campaign launched for Sudanese refugees in Ethiopia

The Gambella region of Ethiopia, which is currently home to more than 185,000 South Sudanese refugees escaping violence in their country, is the site of a mass cholera vaccination campaign launched by Doctors Without Borders (Medecins Sans Frontieres, or MSF), according to an Aug 26 Reuters report.

The oral vaccine, which is given in two doses, is being administered at fixed sites and through mobile teams. More than 300 MSF workers have been deployed to the area.

The campaign, supervised by the Administration for Refugee and Returnee Affairs with technical support from United Nations agencies, reached 151,723 (85%) of the refugees in its first round; the second round began Aug 15.

A cholera epidemic was declared in June in South Sudan. Given the large number of Sudanese fleeing to neighboring Ethiopia, the overcrowded conditions and poor sanitation in the refugee camps, and the fact that cholera is endemic in Gambella, the area "could provide a perfect breeding ground for the disease," says the report.

MSF's emergency coordinator in Gambella, Madi Foura Sassou, said the vaccine is more than 60% effective.
Aug 26 Reuters report

Ebola Scan for Aug 28, 2014

News brief

NIH part of international consortium to speed Ebola vaccine trials

The National Institutes of Health (NIH) has partnered with an international-based consortium based in Britain to fast-forward work on an Ebola virus vaccine developed by GSK that has shown promise in nonhuman primate studies. The first phase 1 human trial is slated to start next week by scientists from the NIH's National Institute of Allergy and Infectious Diseases (NIAID), with similar trials starting next month in the United Kingdom, Gambia, and Mali.

The international consortium includes the Wellcome Trust and Britain's Medical Research Council and Department for International Development. A $4.6 million grant from the groups will allow researchers at the University of Oxford to start parallel safety tests of the vaccine, which are slated to begin in the middle of September as soon as the groups receive expedited ethical and regulatory approvals.

GSK said in a statement that the consortium's funding will allow the company to start making up to 10,000 more doses of the vaccine at the same time clinical trials are being done so that if the trials are successful, the company can immediately get supplies to the World Health Organization for emergency immunization campaigns targeted to high-risk areas.

The company's vaccine candidate is aimed at the Zaire species of Ebola, which is the one responsible for West Africa's outbreak. It uses a single Ebola virus protein to induce an immune response and does not contain infectious virus, GSK said. It said the NIH is providing vaccine for the Oxford group's trial and is also testing a related vaccine designed to protect against two Ebola strains—Zaire and Sudan.

If the vaccine appears to be safe and effective in the Oxford trial, research teams will use it to launch trials in Gambia and Mali that are designed to test different dosages. GSK said the addition of the two West African arms of the study is intended to ensure that the trials account for differences in European and African populations that might affect safety and immune response.
Aug 28 NIH press release
Aug 28 GSK press release
Aug 28 Wellcome Trust press release

Treatment of US Ebola patients yields clinical pearls

The recent treatment of two US medical workers who were infected with Ebola virus in Liberia at Emory University Hospital in Atlanta offered an unprecedented opportunity to observe the course of the disease and its treatment in a well-equipped and -staffed setting, yielding lessons that could help doctors working in the field in West Africa's outbreak, according to a report yesterday in Scientific American.

One of the magazine's writers, Dina Fine Maron, interviewed Bruce Ribner, MD, an internal medicine doctor who led the team that treated patients Kent Brantly, MD, and Nancy Writebol at the facility. Both recovered from the disease and were released from the hospital last week.

Ribner said hospitals and treatment centers in the outbreak countries don't have the capacity to measure important parameters, such as electrolyte and blood protein levels, but clinical interventions can be used to address both issues, even in the absence of testing. He said both patients had low sodium and potassium levels, a consequence of fluid loss after bouts of vomiting and diarrhea. Even if clinicians in Africa can't measure the levels, it's important to be aware that the levels could be low in fluid-loss instances.

Ribner also said that both patients had edema, the fluid loss into tissues resulting from liver damage and resulting insufficient protein levels in the blood. "So one of the takeaway messages is to pay closer attention to that and perhaps early on try to replace some of these proteins that patients' livers lack," he said.

Upon discharge, the two patients were given the standard US Centers for Disease Control and Prevention recommendation to avoid having unprotected sex for 3 months, Ribner said. He added that while studies have shown that after recovery Ebola patients can shed genetic material from the virus in semen and vaginal secretions, there have been little attempts to show that people shed viable virus.

Media reports said Brantly received convalescent serum and that both patients received the experimental Ebola drug ZMapp. Ribner said, however, that it's not clear if the treatments were beneficial. He added that the benefits of airlifting patients to developed countries include replacement of fluid and electrolytes, platelets, and blood proteins.

"I think one of the messages that is going out from many sources is we really have to help countries such as the ones involved in this outbreak to develop their medical infrastructure. Hopefully in five years they will have this infrastructure," Ribner said.
Aug 27 Scientific American report