Evidence of Risk for H2N2 1957 Pandemic Flu

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Evidence of Risk for H2N2 1957 Pandemic Flu
April 18, 2005
Commentary
Recombinomics
>> Even if a sample included in a test kit is a strain of a deadly virus, the sample is not necessarily dangerous because it has been diluted, said Dr. Jared Schwartz, an officer with the College of American Pathologists??.
Schwartz said he is not aware of any evidence that suggests a risk of infection from the strain.
Companies that make the test kits typically only have diluted virus samples, he said. <<
The evidence for risk of infection from the H2N2 1957 pandemic strain is pretty overwhelming. The alert that was issued indicated Specimen VR 1-05 in the VR1-A 2005 Survey was ATCC VR-100. VR-100 from American Type Culture Collection (ATCC) is A/Japan/305/57(H2N2). As indicated by its name, the human virus was isolated in Japan in 1957 and is H2N2.
Since H2N2 has been out of human circulation since 1968, those born after 1968 would have limited immunity. Thus, infection by the virus would likely cause problems in younger people. Most of the lab technicians who would likely come into contact with the sample are born after 1968.
The sample was a reference sample, in part because it grows easily, just one of the reasons it has an ATCC number and is sold commercially. Thus, it is more likely than most flu isolates to be easily infectious.
The sample was lyophilized, which is a procedure that removes the water from a sample and makes the resulting powder light, fluffy, and aerodynamic. It is one method used to weaponize anthrax and, as was seen in the Hart Senate Office building. Opening an envelope of dried spores was sufficient to aerosolize the material, and contaminate scores of office workers. Thus, opening a vial of the lyophilized material outside of a biocontainment hood would risky.
However, as was demonstrated by the sequence of events that led to the discovery of the mislabeled virus, opening the vial inside a hood also readily spreads the virus. Exposing a clinical specimen inside the same hood contaminated the sample. When the sample was sent to the Canadian National Labs for routine testing, there was enough virus contaminating the clinical sample to register as a positive H2N2 sample. This sounded alarm bells because H2N2 is not currently circulating among humans. The patient did not have the flu, and the testing was routine. There were no special procedures used for growing the virus. However, there was enough virus contaminating the sample to resister as a positive in the routine test.
Thus, the evidence for issuing a warning was quite substantial, and failure to understand the associated risk is clearly cause for concern.