News Scan for Oct 21, 2013

News brief

Two more MERS cases reported in Saudi Arabia

Saudi Arabia has reported two more Middle East respiratory syndrome coronavirus (MERS-CoV) cases in the past few days, both in men living in the Riyadh region, according to a press account and a translated government statement.

One case is in a 73-year-old man who has chronic diseases and is being treated in an intensive care unit (ICU), said an Arab News report yesterday. The man had not traveled outside the Riyadh area recently, but the story gave no other details.

The other case involves a 54-year-old man who likewise has chronic diseases and is in an ICU, according to a machine-translated statement yesterday from the Saudi Ministry of Health (MOH). It gave no other details.

An MOH coronavirus Web site shows that 121 MERS-CoV cases, with 51 deaths, have been confirmed in Saudi Arabia. The World Health Organization (WHO), which has not yet confirmed the two cases, lists an official MERS-CoV count of 139 cases and 60 deaths, but some other groups list slightly higher counts.

In the wake of the Hajj pilgrimage, which ended Oct 18, Saudi officials said there has been no evidence of any MERS cases or other life-threatening infectious diseases among pilgrims, according to the Arab News report. But, as many observers have noted, the MERS-CoV incubation period is long enough so that cases could still surface in pilgrims who have returned home.
Oct 20 Arab News story
Translated Oct 20 MOH statement

WHO reports possible polio cluster in Syria

A cluster of people with acute flaccid paralysis in Syria may signal the country's first wild poliovirus infections since 1999, the WHO said.

The unspecified number of cases occurred in Deir Al Zour province earlier this month and are being investigated, the agency said in an Oct 19 alert.

"Initial results from the national polio laboratory in Damascus indicate that two of the cases could be positive for polio—final results are awaited from the regional reference laboratory of the Eastern Mediterranean Region of WHO," the agency said in the alert.

Syria's planned urgent response includes a surveillance alert, the WHO said, and supplemental immunizations are in the offing for neighboring countries.

In an apparent reference to the nation's civil war, the alert said, "Syria is considered at high-risk for polio and other vaccine-preventable diseases due to the current situation."
Oct 19 WHO alert

Study: Teen Tdap vaccination associated with lower infant pertussis

Widespread vaccination of US adolescents against pertussis (whooping cough) was associated with lower rates of infant hospitalization for the disease, according to a study today in Pediatrics.

Researchers from Cincinnati Children's Hospital Medical Center and the University of Michigan analyzed data from before and after the Centers for Disease Control and Prevention recommended tetanus-diphtheria-acellular pertussis (Tdap) vaccine for all adolescents in 2006. The team used statistics from the Nationwide Inpatient Sample database and excluded 2006 and 2007 data, during early implementation of the Tdap recommendations.

In 3 of the 4 years examined, the investigators found significantly lower hospitalization rates for infants than would have been expected with no adolescent immunization. The observed rate of infant hospitalizations for pertussis per 10,000 infants was:

2008: 3.85 (expected: 10.09)
2009: 5.84 (expected: 10.75)
2010: 7.78 (expected: 11.36)
2011: 3.27 (expected: 12.00)

The 2010 drop was not statistically significant.

"We know infants get pertussis from family members, including older siblings," said lead author Katherine A. Auger, MD, in a Cincinnati Children's press release. "While it is encouraging to find a modest reduction in infant hospitalizations after the vaccination of adolescents began, there were still more than 1,000 infants hospitalized for pertussis in 2011. Expecting parents should discuss with their doctors the need for vaccination of all caregivers before the birth of a baby."
Oct 21 Pediatrics abstract
Oct 21 Cincinnati Children's Hospital Medical Center news release

Flu Scan for Oct 21, 2013

News brief

Study: Flu vaccine plus immune suppressor may offer broader protection

US researchers reported yesterday that giving mice a flu vaccine and simultaneously treating them with rapamycin, an immune-suppressing drug, caused them to generate antibodies that were protective against other flu strains, including H5N1 and H7N9.

The authors, from St. Jude Children's Research Center in Memphis and the Fred Hutchinson Cancer Center in Seattle, reported their findings in Nature Immunology.

The researchers infected groups of mice with an H3N2 flu strain by way of vaccination and treated them with rapamycin or a placebo for 28 days, starting the day before vaccination. When the mice were later exposed to an H5N1 virus, the rapamycin group had a much higher survival rate than the placebo group. In addition, rapamycin-treated mice had significantly higher survival when later exposed to H7N9 and H1N1 viruses, according to the report.

Further, when the team transferred serum from vaccinated to unvaccinated mice, the unvaccinated mice were also protected from later H5N1 infection, which indicated that protection came from antibodies rather than from other immune system components, according to a St. Jude press release.

Rapamycin inhibits the kinase mTOR, which is involved in cell survival and proliferation, according to the release. "Inhibiting mTOR disrupted generation of the antibodies that target specific regions of the HA [hemagglutinin] proteins that are unique to each flu strain," leading to a more diverse set of antibodies, it says.

Previous research has indicated that memory CD8+ and CD4+ T cells play a role in broadening the immune response against flu viruses, but the team found that CD8+ T cells were not required for enhanced protection in rapamycin-treated mice, the release states.

"The findings highlight a novel way to generate antibodies that recognize and target proteins shared by most influenza A strains rather than those unique to each strain," it says.
Oct 20 Nature Immunol study
Oct 20 St. Jude press release

Anaphylaxis elevated after H1N1 vaccination, Quebec study says

Anaphylaxis after receipt of the 2009 pandemic H1N1 (pH1N1) vaccine with the AS03 adjuvant was much more common in Quebec compared with seasonal trivalent influenza vaccine (TIV), according to a new study using active surveillance data published in Vaccine.

Data from passive surveillance has already identified 33 cases of anaphylaxis after receipt of adjuvanted pH1N1 vaccine in Quebec, a rate 20 times higher than for TIV without adjuvant in the previous 6 years in the province, the study authors say.

Using the Brighton collaboration case definition of anaphylaxis, the Quebec researchers identified 58 anaphylaxis cases via active surveillance, which represents an incidence of 13 cases per million doses administered, they wrote. TIV averages less than 1 case per million doses.
Oct 19 Vaccine abstract