VACCINES: AN ONLINE CONFERENCE
By RFD Columnist, Dr. F. Edward Yazbak
Falmouth, Massachusetts, USA
The Centers for Disease Control and Prevention (CDC) publishes weekly reports during the influenza season. The latest available report (1), written on November 24, describes the Influenza activity during week 46 of 2004 (November 14 to 20).
The population of the United States was estimated at slightly above 294.8 million that week.
A total of 1,118 specimens were submitted for viral testing to the U.S. World Health Organization (WHO) and National Respiratory and Enteric Virus Surveillance System (NREVSS) collaborating laboratories during that week. Of these, 36 (3.2%) were positive: 9 were influenza A (H3N2) viruses, 18 were influenza A viruses (not sub-typed), and 9 were influenza B viruses.
The two laboratories tested 11,899 specimens in all since October. Of these, 170 (1.4%) were positive: 134 (78.8%) were influenza A and 36 (21.2%) were influenza B viruses. Over 50% of the isolated influenza A viruses were sub-typed and identified as influenza A-H3N2.
Twenty-three states have not yet had laboratory-confirmed influenza.
Since October 1, the CDC conducted antigenic testing on a total of 11 influenza viral isolates: nine influenza A (H3N2) viruses and 2 influenza B viruses. All of the influenza A (H3N2) isolates were A/Fujian/411/2002-like (H3N2), the influenza A (H3N2) component in the 2004-05 flu vaccine. Both influenza B viruses were B/Shanghai/361/2002-like, also the influenza B component of this year’s vaccine. It is indeed most fortunate that after this year’s National crisis, we at least seem to have, based on eleven tests, the right choice of vaccine strain.
According to the CDC, there were fewer visits for “influenza –like illnesses” in week 46 than the National baseline and so far, there have been no pediatric “flu-related deaths”.
The flu season started early in the fall of 2003 and the number of cases peaked between mid-December and mid-January. During week 46 last year, there were over 1200 isolates nationwide (compared to 36 this year). The percentage of respiratory specimens testing positive for influenza peaked at 35.2% during the week ending November 29, 2003. The largest number of isolates was reported during the week ending December 13. The peak percentage of specimens testing positive for influenza during the previous 4 seasons (1999-00, 2000-01, 2001-02, and 2002-03) ranged from 23% to 31%. (2). It is noteworthy that as previously mentioned, only 1.4% of submitted cultures were positive so far this year. It is obviously possible that the other 88.6% of cultured people did indeed have the flu, even if their cultures were negative. It is also conceivable that they did not.
The panic, frenzy and long lines of the earlier weeks have subsided as more vaccine is becoming available. British manufacturer, GlaxoSmithKline who produces 10% of the world’s flu vaccine,has applied for FDA approval for its Fluarix vaccine. Prompt approval is expectedand GSK could deliver 4 million doses this season and probably more in the future.
The recommended 2004-05 trivalent influenza vaccine for the United States contains A/New Caledonia/20/99-like (H1N1), A/Fujian/411/2002-like (H3N2), and B/Shanghai/361/2002-like viruses. For the A/Fujian/411/2002 (H3N2)-like antigen, manufacturers will use the equivalent A/Wyoming/3/2003 (H3N2) virus, and for the B/Shanghai/361/2002-like antigen, manufacturers will use the equivalent B/Jilin/20/2003 virus or B/Jiangsu/10/2003 virus.
The CDC has several suggestions (3) for those who could not or would not be vaccinated.
A recently published recipe for chicken soup (4) by the Director of Pulmonary Medicine at a distinguished Medical Center is also worth trying.
A review of the whole U.S. Influenza season will be reported to Red Flags members as soon as it is available.
- http://www.cdc.gov/flu/weekly/fluactivity.htm (Current weekly flu report)