RecombinomicsCommentary 23:50
November 20, 2009
Norway reported finding a mutated virusin three people who died or were severely ill. The mutation, known asD222G on the receptor binding domain, allow the virus to grow deeper inthe lungs.
The mutation does not appearto be circulating and may have spontaneously arisen in the threepatients, said Geir Stene-Larsen, director of the Norwegian Instituteof Public Health. Only 3 of Norway's 70 tested samples had it.
Asked about that, Dr.Schuchat said the same mutation had also been found in mild cases inseveral countries, and it did not make the virus resistant to vaccineor to treatment with drugs like Tamiflu. She said she did not want to"underplay" it, adding that "it's too soon to say what this will meanlong term."
The D222G mutation allowsthe virus to bind to receptors on cells lining the lungs, which areslightly different from those in the nose and throat. Henry L. Niman, aflu tracker in Pittsburgh, has been warning for a week that D225G - thesame mutation under a different numbering system - has been repeatedlyfound in Ukraine, which is in the grips of a severe outbreak and wheresurprising numbers of people have died with lung hemorrhages - the kindof pneumonia that can be caused by an immune system's "cytokine storm"attacking a new virus.
The above comments from the Donald McNeil updatein tomorrow's New York Times are the first direct acknowledgement thatthe receptor binding domain change in Norwayand Ukraine are the same. Earlier the WHO had put out an updateon the change in Norway and noted that a similar change had been seenelsewhere, and included Ukraine in the list of countries.
In earlier Ukraine updates WHO did not acknowledge any receptor bindingdomain changes, but the sequencesreleased at GISAID by Mill Hill had D225G in four of the ten HAsequences, which precisely matchedthe four fatalities, raising concern that the previously described "destructionof both lungs" was driven by the acquisition of D225G. Thegroup in Norway also found the change in dead or dying patients,further supporting a significant role of this change the the cytokinestorm associated with this acquisition.
This change has been reported in a number of recently described casesincluding two fatal cases in Sao Paulo, a seriously ill case in China,and cases in Sydney, Australia and Vladivostok. The polymorphism had also been seen in earlier isolates in the UnitedStates, Mexico, Spain, and Japan.
The role of this change in fatal cases may be dependent on the viralload. The cytokine storm is precipitated by high levels of virus, andlower levels may produce milder disease.
The above report, noting the identity between Norway and Ukraine shouldlead to more detailed analysis of tissue samples from fatal cases,which may contain an increased frequency of D225G, a receptor bindingdomain change identified in 1918and 1919 samples.
Source: http://www.recombinomics.com/News/11200906/D225G_Norway_Ukraine_WHO.html 
