Thursday, April 29, 2010

NOVEL (SWINE) H1N1 INFLUENZA VACCINATION: DISTINGUISHING MYTH FROM REALITY

This article is intended for a limited readership of healthcare professionals and practitioners.

Efforts to suppress the spread of the 2009 H1N1influenza strand have been mostly centered on massive vaccination regimes, involving the general population. These practices encouraged by WHO, have however found limited public response. The clinical experience gained from two consecutive winter seasons in the Southern (mainly Australia) and the Northern hemisphere right after the rapid outbreak of 2009, which were expected to favor the worldwide spread of the disease, have so far supported the aforementioned reluctance of the public. Although the publicity gained by the media may be partially blamed for the hasty mass vaccination decision, the lack of accumulated solid scientific knowledge and experience seems to be the main reason why the medical community under the burden of the wide spread fear for possible repercussions, resorted in this solution.

Influenza vaccines are frequently ineffective. At present, this is a major obstacle to an effective practical immunization procedure and one of the reasons why influenza vaccination traditionally is offered only to high-risk populations. Even traditional influenza vaccination policy, that in most developed countries attempts to reduce the mortality of persons over 65 years of age, is under dispute (SIMONSEN AND AL LANCET INFECT DIS. Oct 7(10), 2007, 658-66).

Furthermore, despite the fact that many people have been admitted to ICUS or died of H1N1 all over the world, the proportion of deaths from H1N1 does not differ from this of classic seasonal influenza, as becomes obvious in countries where the winter epidemic stroke has been sufficiently studied (figure 1), and in daily clinical practice. In clinical trials, concerning the profile of seriously ill patients, these in general, had at least one underlying medical problem including asthma, diabetes, heart/lung/ neurologic disease, obesity (mean BMI greater than 30) pregnancy (70-93%), or there was a long interval from onset of symptoms to treatment with antiviral therapy (48 hours, or longer).






Figure 1: Percentage of all deaths classified as influenza and pneumonia, in Australia

WA Registry of Births, Deaths and Marriages, 1 January , 2008 to 23 August 2009 WA ‘Virus Watch’ Report. http://www.health.gov.au Accessed December 30, 2009.

As H1N1 risks and immunization benefits have been overestimated, it seems prudent to vaccinate only high risk groups.
ANASTASIA MOSCHOVAKI, M.D.  
Department of Internal Medicine, Athens Medical Center, Greece  

• Office: 10 Fragopoulou Str. 14561, Kifissia 

• Tel./Fax: +30 210 6252770 

• Hospitalization - emergencies: +30 6945575287



• E-mail: amoschovaki@yahoo.gr 

REFERENCES 

1. SEEMA JAIN ET AL Hospitalized patients with 2009 H1N1 influenza in States April June 2009.NEW ENLAND JOURNAL November 12 2009, 361:1935-1944. 

2. Global Alert and Response (GAR)—Pandemic (H1N1) guidance documents, http://www.who.int/csr/resources/publications/swineflu/en/. Accessed June 30, 2009.  

3. ANAND KUMAR ET AL Critically ill patients with 2009 H1N1 infection in Canada. JAMA 2009; 302(17):1872-1879. 

4. GUILLERMO DOMINGUEZ CHERIT ET AL Critically ill patients with 2009 H1N1 infection in Mexico. JAMA 2009;302(17):1880-1887.  

5. RYAN ZARYCHANSKI ET AL Correlates of severe disease in patients with 2009 pandemic influenza virus infection. CMAJ February 23, 2010; 182 (3). 

6. LONE SIMONSEN ET AL Mortality benefits of influenza vaccination in elderly people: an ongoing controversy. LANCET INFECT DISEASES OCT;7(10):658-66.

7. CARMAN WF ET AL Effects of influenza vaccination of health-care workers on mortality of elderly people in long-term care: a randomized controlled trial. LANCET 2000; 355:93-7. 

8. JAMES A. WILDE ET AL Effectiveness of Influenza Vaccine in Health Care Professionals A Randomized Trial. JAMA 1999;281:908-913.

9. ANDREW C HAYWARD ET AL Effectiveness of an influenza vaccine programme for care home staff to prevent death, morbidity, and health service use among residents: cluster randomized controlled trial. BMJ 2006; 333:1241.  

10. MANGTANI P ET AL A cohort study of the effectiveness of influenza vaccine in older people performed using the United Kingdom general practice research database. J INF DIS 2004 Jul 1;190(1):1-10. 

11. T JEFFERSON ET AL, Efficacy and effectiveness of influenza vaccines in elderly people: a systematic review. LANCET 2005; 366: 1165–74. 

12. KRISTIN L. NICHOL ET AL, Effectiveness of Live, Attenuated Intranasal Influenza Virus Vaccine in Healthy Working Adults
A Randomized Controlled Trial. JAMA 1999; 282:137-144. 

13. T JEFFERSON ET AL Assessment of the efficacy and effectiveness of influenza vaccines in healthy children: systematic review. LANCET Volume 365, Issue 9461, 26 February 2005-4 March 2005, Pages 773-780.  

14. E NEGRI ET AL VACCINE Influenza vaccine in healthy children: a meta-analysis. VACCINE 2005; 23: 2851-2861.

15. TRANG VU ET AL A meta-analysis of effectiveness of influenza vaccine in persons aged 65 years and over living in the community. VACCINE Volume 20, Issues 13-14, 15 March 2002, Pages 1831-1836.


  
16. DEMICHELI V ET AL Vaccines for preventing influenza in healthy adults. COCHRANE DATABASE SYST REV 2004 ;(3):CD001269. 

17. FEDSON DS ET AL Influenzae vaccination in 22 developed countries : an update to 1995. VACCINE 1997 ; 15 (14) 1506-11. 
18. CAROLYN BUXTON BRIDGES ET AL Effectiveness and Cost-Benefit of Influenza Vaccination of Healthy Working Adults A Randomized Controlled Trial. JAMA 2000;284:1655-1663.

19. Percentage of all deaths classified as influenza and pneumonia, WA Registry of Births, Deaths and Marriages, 1 January, 2008 to 23 August 2009. http://www.health.gov.au Accessed December 30, 2009.


20. 2009 H1N1 Flu, http://www.cdc.gov, Accessed April 29, 2010. 

21. Εμβόλιο γρίπης πανδημικό εμβόλιο νέας γρίπης και αποτελεσματική πρόληψη σοβαρών επιπλοκών κατά τη μαχόμενη ιατρική πράξη: Μια αμφιλεγόμενη σχέση. http://novelswineinfluenza.blogspot.com. Accessed December 15, 2009.