News Scan for Jun 10, 2014

News brief

MMRV may slightly increase post-vaccine seizures, study says

The risk of post-vaccination seizures in 1-year-olds was twice as high with the combined measles-mumps-rubella-varicella (MMRV) vaccine compared with the MMR and varicella vaccines (MMR+V) administered separately, but the absolute risk is small, according to a study yesterday in the Canadian Medical Association Journal (CMAJ).

In Canada the MMRV vaccine has replaced the two separate vaccines for childhood immunizations, but US healthcare providers have both options.

Researchers analyzed data on 227,774 children aged 12 to 23 months who received either MMR+V or the MMRV vaccine from 2006 through 2012 in Alberta.

They found the relative risk of seizures 7 to 10 days after vaccination was 1.99 with MMRV compared with MMR+V. But the MMRV vaccine was associated with an average of only 3.5 extra seizures for every 10,000 doses of vaccine, they noted.

"Combining MMR and varicella into a single vaccine decreases pain for children and distress for parents, thus addressing common barriers to vaccine uptake, and may improve vaccination coverage levels and decrease immunization delivery costs," the authors wrote.

"Febrile seizures are typically self-limiting and rarely have long-term effects, but they can be extremely distressing for parents, may precipitate acute care visits and may undermine confidence in immunization programs."

The study's findings are consistent with the results of a study of the US version of the MMRV vaccine, according to a CMAJ press release.
Jun 9 CMAJ abstract
Jun 9 CMAJ news release

 

WHO alarmed by measles outbreaks in Somalia

A surge of measles cases in Somalia has put thousands of children, many of them malnourished, at risk for disability or death unless they are vaccinated soon, the World Health Organization's Regional Office for the Eastern Mediterranean (WHO EMRO) said today.

The agency said 1,350 measles cases were reported in March and April—four times the number in the same period last year—and another 1,000 cases were identified in May.

So far health authorities have responded with small-scale vaccination campaigns, and plans call for larger campaigns this month targeting 500,000 children in Bari, Nugaal, Mudug, Banadir, and Lower Juba, the WHO said. Campaigns are being supported by the WHO and the United Nations Children's Fund (UNICEF).

"We have a very high number of malnourished Somali children," Sikander Khan, UNICEF's Somalia representative, said in the WHO statement. "Malnourished children here are more susceptible to disease and are more likely to die or suffer life-long disability such as blindness, deafness, or brain damage as a result of contracting measles."

The WHO said 20 years of conflict have devastated Somalia’s health sector, leaving the country with some of the worst health and nutrition indicators in the world. An estimated one in five children dies before reaching age 5, with measles as one of the main causes.

It estimated that less than a third of Somali children under 1 year old received measles vaccine in 2013 through routine immunization services, the statement said. Urgently needed is a nationwide vaccination campaign targeting 5 million children from 9 months to 15 years old, it added.
Jun 10 WHO EMRO statement

 

Study finds rotavirus vaccine cut healthcare visits, costs

The introduction of the rotavirus vaccine has dramatically cut healthcare use and costs since its introduction in 2007, according to a study published yesterday in Pediatrics.

The research, by a team from the US Centers for Disease Control and Prevention (CDC), expands on an initial study in 2008 that found a drop in hospitalizations. Their review also includes a second rotavirus vaccine that was incorporated into federal recommendations in 2008.

The team analyzed diarrhea-linked data in children younger than age 5 from a health insurance claims database from 2001 through 2011. They also compared rates in vaccinated and unvaccinated kids, both before and after the vaccine was introduced.

Rotavirus hospitalizations dropped 75% in 2007-08, with further reductions through 2010-11. After the vaccine was introduced, rotavirus hospitalizations declined in unvaccinated children: 50% in 2007-08 and 77% and 25% in the following two seasons.

Researchers also saw declines in other types of health encounters, such as emergency department and doctor's office visits, with declines that grew as vaccine coverage expanded. They found that the pentavalent and monovalent vaccines were both highly effective at decreasing hospitalization and emergency department visits, with both providing similar protection.

The team found no waning immunity for the pentavalent version, which is the first vaccine that was introduced. They also found benefits for unvaccinated kids, though the magnitude varied over the seasons.

Overall, the authors estimated that the vaccine reduced the healthcare burden by about 1.5 million visits and about $924 million in costs.
Jun 9 Pediatrics abstract

 

Study points to avian origin of virus in first H10N8 case

Culturing an H10N8 avian flu virus from the first known human case in chicken eggs did not result in mutations, but culturing it in MDCK (Madin-Darby canine kidney) cells did, Chinese researchers reported yesterday in Emerging Infectious Diseases.

The investigators inoculated embryonated chicken eggs and MDCK cells with an H10N8 tracheal aspirate specimen from the first known case-patient, who died last December after a severe illness and multiple organ failure.

The viral genome was highly conserved when cultured in chicken eggs, and the researchers observed no mutations. "This result suggests that the novel A(H10N8) virus might have been highly adapted to an avian-like host before it was transmitted to the human host (i.e., the first patient)," they wrote.

In MDCK cells, however, the virus genome underwent substantial mutations. "This finding implies an ongoing adaptive microevolution of the virus in a mammalian environment," they said.

The authors conclude, "Taken together, our results favor the proposal that the novel influenza A(H10N8) virus has an avian origin; however, more research is required to establish the definite origin of the emerging influenza virus."

Only two additional human H10N8 infections have been reported.
Jun 9 Emerg Infect Dis study

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