Letter from Nurse Livengood Re: Asian Avian Flu (H5N1)

Thanks for the great blog. I have been looking for this information for a long time. Thanks.

In regards to the flu: here is some information from two good sources. The first is from the August 13th issue of the Lancet (major medical journal from the UK):
The Lancet 2005; 366:533-534
H5N1 Influenza Pandemic: Contingency Plans
Kenneth WT Tsang email address a, Philip Eng b, CK Liam c, Young-soo Shim d and Wah K Lam d

The current epidemic of the highly pathogenic H5N1 strain of avian influenza, with a mortality of 58%, appears relentless in Asia, particularly in Vietnam and Thailand.1 Although inefficient, there is some evidence of human-to-human transmission for the H5N1 virus.2 A possible catastrophic pandemic could, therefore, emerge should re-assortment of viral antigens occur resulting in a highly infectious strain of H5N1. Influenza pandemics in 1917–18, 1957–58, and 1968–69 have already caused approximately 15, 4, and 0·75 million deaths worldwide, respectively.

A vaccine for H5N1 will not be available in the foreseeable months. Even if pharmaceutical manufacturing begins soon after an outbreak, there would not be a sufficient supply for the countries most in need—ie, the Asian nations. Antiviral drugs are consequently the only specific treatment, pending availability of effective vaccines. These include M2 inhibitors (amantadine and rimantadine), which are ineffective against H5N1 in vitro, and the neuraminidase inhibitors (oseltamivir and zanamivir).3 The neuraminidase inhibitors reduce the severity and duration of symptoms, and prevent
clinical influenza as post-exposure and seasonal prophylaxis.4 Influenza contingency plans by the WHO and most governments generally advocate detection, isolation, staff protection, and the start of antiviral treatment for patients, and their contacts.5 Many governments, including those of Hong Kong, Thailand, Singapore, Malaysia, and Korea, have already stockpiled, at a very substantial expense, vast quantities of oseltamivir to prepare for an outbreak.5

This next one comes from an ACIP ( Advisory Committee on Immunization Practices) publication: Influenza Vaccine Composition
Both the inactivated and live, attenuated vaccines prepared for the 2005–06 season will include A/California/7/2004 (H3N2)-like, A/New Caledonia/20/99 (H1N1)-like, and B/Shanghai/361/2002-like antigens. For the A/California/7/2004 (H3N2)-like antigen, manufacturers may use the antigenically equivalent A/New York/55/2004 (H3N2) virus, and for the B/Shanghai/361/2002-like antigen, manufacturers may use the antigenically equivalent B/Jilin/20/2003 virus or B/Jiangsu/10/2003 virus. These viruses will be used because of their growth properties and because they are representative of influenza viruses likely to circulate in the United States during the 2005–06 influenza season. Because circulating influenza A (H1N2) viruses are a reassortant of influenza A (H1N1) and (H3N2) viruses, antibody directed against influenza A (H1N1) and influenza (H3N2) vaccine strains provides protection against circulating influenza A (H1N2) viruses. Influenza viruses for both the inactivated and live attenuated influenza vaccines are initially grown in embryonated hens eggs. Thus, both vaccines might contain limited amounts of residual egg protein. For the inactivated vaccine, the vaccine viruses are made noninfectious (i.e., inactivated or killed) (63). Subvirion and purified surface antigen preparations of the inactivated vaccine are available. Manufacturing processes differ by manufacturer. Manufacturers might use different compounds to inactivate influenza viruses and add antibiotics to prevent bacterial contamination. Package inserts should be consulted for additional information.

Hope these are helpful (or at least interesting)! – Nurse Alma Frances Livengood