Reduced vaccine strain fitness suspected in FluMist protection problems

Medimmune scientists have been investigating what's behind the decreased FluMist effectiveness that prompted US vaccine advisors to recommend against it this year, and today they reported that reduced fitness of H1N1 vaccine virus strains are the likely culprit. Researchers from the company, which makes the live attenuated influenza vaccine (LAIV), reported their initial findings today in a letter to Eurosurveillance.

They said they found signs of reduced replication in both the influenza A/California H1N1 vaccine strain and the more heat-stable influenza A/Bolivia H1N1 vaccine strain that replaced it.

Researchers said they are investigating other possibilities, but so far they haven't found evidence that the reduced effectiveness is related to vaccine-virus interference, quadrivalent formulation, or to prior vaccination. They also explored the possibility of reduced thermostability, which they said might have contributed to the low vaccine effectiveness against H1N1 in the 2013-2014 season in the United States; however, they said it doesn't explain the reduced protection in the 2015-2016 season, during which FluMist contained the more heat stable A/Bolivia H1N1 vaccine strain.

The team said the company has launched a multifaceted investigation into the causes of reduced effectiveness, with an eye toward developing a more effective H1N1 strain to include for the 2017-2018 FluMist formulation.
Nov 10 Eurosurveill report
Jun 22 CIDRAP News story "ACIP recommends against inhaled flu vaccine for next season"

MERS sickens one, kills another in Saudi Arabia

For the second day in a row, Saudi Arabia's ministry of health (MOH) reported a new MERS-CoV case from Kharj. The case involved a 68-year-old Saudi man who had primary exposure to the virus, meaning he did not contract it from another patient.

The man is hospitalized in critical condition. The patient reported from the same city yesterday is a 53-year-old man who had contact with camels. Kharj is located in the central part of the country.

In its update today on Middle East respiratory syndrome coronavirus (MERS-CoV), the MOH also reported another death from the disease involving a previously announced patient, a 72-year-old Saudi man from Riyadh who had underlying health conditions.

The new developments lift Saudi Arabia's MERS-CoV total to 1,477 cases, 617 of them fatal. Eight people are still being treated for their infections.
Nov 10 Saudi MOH statement

Gene study hints at Legionella adaptation to modern niches

Genetic sequencing and phylogenic analysis of Legionella pneumophilia genomes suggests that four new clones have emerged in Europe with signs of rapid spread over long distances, hinting that they may have adapted to manmade niches, which could be connected by human infection and transmission.

The research, reported in the November issue of Genome Research, was led by scientists based at Wellcome Trust Sanger Institute in the United Kingdom and the Pasteur Institute in Paris. They looked at 364 genomes, including 337 from the five sequence types that cause clinical disease. They included 27 others to round out the genetic diversity of the species.

According to their findings, the oldest clone spread globally between 1940 and 2000. They said the large proportion of clinical cases caused by the new internationally dispersed clones, which showed signs of convergent evolution, was surprising for an environmental bacterium typically considered to be an opportunistic threat.

Adaptation to new niches, such as modern manmade water systems, might explain the genetic observations. Researchers said it's also possible that the lineages are more efficient at infecting humans.
Nov Genome Res abstract

Measles vaccine in Nigeria as WHO and UNICEF release disease report

The World Health Organization (WHO) launched a massive measles vaccine campaign to stamp out an outbreak in northern Nigeria. So far, there have been 744 suspected cases and 2 deaths in the Borno state, which is under rule of the terrorist organization Boko Harum. The outbreak began in September.

More than 10,000 children were vaccinated in the last week, most of them in IDP (internally displaced person) camps. The WHO said their goal was to eventually to reach more than 75, 000 children aged 6 months to 15 years of age in 18 IDP camps.

In other measles news, the WHO and UNICEF also released a report on the global state of measles infections in the last 15 years. Despite a 79% worldwide decrease in measles incidence (which translates to approximately 20 million lives saved), almost 400 children still die each day from the highly infectious disease.

According to the report, "In 2015, about 20 million infants missed their measles shots and an estimated 134,000 children died from the disease. The Democratic Republic of the Congo, Ethiopia, India, Indonesia, Nigeria and Pakistan account for half of the unvaccinated infants and 75% of the measles deaths."

In 2015, it’s estimated 134,000 infants died from measles.
Nov 10 WHO press release
WHO measles page