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. 2010 Feb 18;73(2):62–66. doi: 10.1016/S1726-4901(10)70003-4

Seroprevalence of Antibodies to Pandemic (H1N1) 2009 Influenza Virus Among Hospital Staff in a Medical Center in Taiwan

Yu-Jiun Chan a,b,g, Chia-Ling Lee g, Shinn-Jang Hwang d,f, Chang-Phone Fung a,f, Fu-Der Wang a,f, David HT Yen e,h, Cheng-Hsien Tsai b, Yi-Ming Arthur Chen i, Shou-Dong Lee c,f,*
PMCID: PMC7129009  PMID: 20171584

Abstract

Background

The pandemic (H1N1) 2009 influenza emerged in April 2009 and spread rapidly and broadly all over the world. In addition to specific antiviral agents, massive vaccination is thought to be the most effective way of controlling the transmission. To understand the prevaccination status of certain risk groups, this study compared the baseline sero-prevalence of antibodies to the pandemic (H1N1) 2009 influenza virus among hospital staff with different contact risks and that of the general population.

Methods

A total of 295 serum samples from hospital staff and 244 control serum samples from people who came for physical check-up (control group) were collected between October 2009 and November 2009 before the massive vaccination campaign. The hospital staff was divided into first-line risk personnel (group 1) and second-line risk personnel (group 2) according to their potential contact risks. Hemagglutination-inhibition (HI) tests were conducted to determine the individual serological status. The seropositive rate (SPR, defined as the proportion with HI titer ≥ 1:40) of antibodies to H1N1 influenza virus and its geometric mean titer (GMT) were calculated and compared among the different groups.

Results

The mean ages and sex ratio (% male) of the hospital staff and control groups were 36.9 ± 10.6 years and 52.0 ± 12.6 years, and 24.4% and 57.6%, respectively. The SPR of the antibodies to H1N1 influenza virus of the hospital staff was significantly higher than that of the control group (20.0% vs. 2.9%, p < 0.001). Furthermore, the SPR antibodies to H1N1 influenza virus of group 1 were significantly higher than that of group 2 (30.8% vs. 12.6%, p < 0.001). However, the GMT of antibodies to H1N1 influenza virus of the hospital staff was not significantly different from that of the control group (p = 0.925).

Conclusion

The SPR of antibodies against the pandemic (H1N1) 2009 virus in the hospital staff was higher than that in the general population, reflecting a higher contact risk. Prevaccination surveillance of the immune status of different risk groups may help to prioritize which groups should be vaccinated first.

Key Words: hemagglutination-inhibition test, hospital staff, H1N1 influenza virus, vaccination

References

  • 1.Centers for Disease Control and Prevention (CDC) Update: Swine influenza A (H1N1) infections–California and Texas, April 2009. MMWR Morb Mortal Wkly Rep. 2009;58:435–437. [PubMed] [Google Scholar]
  • 2.Centers for Disease Control and Prevention (CDC) Swine influenza A (H1N1) infection in two children–Southern California, March–April 2009. MMWR Morb Mortal Wkly Rep. 2009;58:400–402. [PubMed] [Google Scholar]
  • 3.World Health Organization . Pandemic influenza A (H1N1) 2009 virus vaccine–conclusions and recommendations from the October 2009 meeting of the immunization Strategic Advisory Group of Experts. WHO; Geneva: 2009. Available at http://www.who.int/csr/disease/swineflu/meetings/sage_oct_2009/en/index.html [Date accessed: December 4, 2009] [PubMed] [Google Scholar]
  • 4.Garten RJ, Davis CT, Russell CA, Shu B, Lindstrom S, Balish A, Sessions WM. Antigenic and genetic characteristics of swine-origin 2009 A (H1N1) influenza viruses circulating in humans. Science. 2009;325:197–201. doi: 10.1126/science.1176225. [DOI] [PMC free article] [PubMed] [Google Scholar]
  • 5.Shinde V, Bridges CB, Uyeki TM, Shu B, Balish A, Xu X, Lindstrom S. Triple-reassortant swine influenza A (H1) in humans in the United States, 2005–2009. N Engl J Med. 2009;360:2616–2625. doi: 10.1056/NEJMoa0903812. Erratum in: N Engl J Med 2009; 361:102. [DOI] [PubMed] [Google Scholar]
  • 6.Dawood FS, Jain S, Finelli L, Shaw MW, Lindstrom S, Garten RJ, Gubareva LV, for the Novel Swine-Origin Influenza A (H1N1) Virus Investigation Team Emergence of a novel swine-origin influenza A (H1N1) virus in humans. N Engl J Med. 2009;360:2605–2615. doi: 10.1056/NEJMoa0903810. Erratum in: N Engl J Med 2009; 361:102. [DOI] [PubMed] [Google Scholar]
  • 7.Petrosillo N, Di Bella S, Drapeau CM, Grilli E. The novel influenza A (H1N1) virus pandemic: an update. Ann Thorac Med. 2009;4:163–172. doi: 10.4103/1817-1737.56008. [DOI] [PMC free article] [PubMed] [Google Scholar]
  • 8.Taiwan Center for Disease Control Medical community command center Circular No. 001–vaccination rate of new central pandemic H1N1 flu outbreak 2009. Available at http://www.cdc.gov.tw/ct.asp?xItem=24836&ctNode=2379&mp=1 [Date accessed: August 4, 2009] [In Chinese]
  • 9.Lan YC, Liu TT, Yang JY, Lee CM, Chen YJ, Chan YJ, Lu JJ. Molecular epidemiology of severe acute respiratory syndrome-associated coronavirus infections in Taiwan. J Infect Dis. 2005;191:1478–1489. doi: 10.1086/428591. [DOI] [PMC free article] [PubMed] [Google Scholar]
  • 10.Wang FD, Chen YY, Lee YM, Chan YJ, Chen TL, Lue JF, Liu CY. Positive rate of serum SARS-CoV immunoglobulin G antibody among healthcare workers. Scand J Infect Dis. 2007;39:152–156. doi: 10.1080/00365540600951226. [DOI] [PubMed] [Google Scholar]
  • 11.World Health Organization . Pandemic (H1N1) 2009–update83. WHO; Geneva: 2009. Available at http://www.who.int/csr/don/2010_01_15/en/index.html [Date accessed: January 15, 2010] [Google Scholar]
  • 12.Taiwan Center for Disease Control Medical community command center Circular No. 049–vaccination rate of new central pandemic H1N1 flu outbreak 2009. Available at http://www.cdc.gov.tw/ct.asp?xItem=26552&ctNode=2379&mp=1 [Date accessed: November 25, 2009] [In Chinese]
  • 13.Gaydos JC, Hodder RA, Top FH, Jr, Soden VJ, Allen RG, Bartley JD, Zabkar JH. Swine influenza A at Fort Dix, New Jersey (January–February 1976). I. Case finding and clinical study of cases. J Infect Dis. 1977;136(Suppl):S356–S362. doi: 10.1093/infdis/136.supplement_3.s356. [DOI] [PubMed] [Google Scholar]
  • 14.Gaydos JC, Hodder RA, Top FH, Jr, Allen RG, Soden VJ, Nowosiwsky T, Russell PK. Swine influenza A at Fort Dix, New Jersey (January–February 1976). II. Transmission and morbidity in units with cases. J Infect Dis. 1977;136(Suppl):S363–S368. doi: 10.1093/infdis/136.supplement_3.s363. [DOI] [PubMed] [Google Scholar]
  • 15.Huang YH. 2009 novel H1N1 influenza: the impact of viral genomic reassortment on immune evasion and vaccine strategy. J Chin Med Assoc. 2009;72:281–282. doi: 10.1016/S1726-4901(09)70372-7. [DOI] [PubMed] [Google Scholar]
  • 16.Nichol KL. Efficacy and effectiveness of influenza vaccination. Vaccine. 2008;26(Suppl):D17–D22. doi: 10.1016/j.vaccine.2008.07.048. [DOI] [PubMed] [Google Scholar]
  • 17.Greenberg ME, Lai MH, Hartel GF, Wichems CH, Gittleson C, Bennet J, Dawson G. Response to a monovalent 2009 influenza A (H1N1) vaccine. N Engl J Med. 2009;361:2405–2413. doi: 10.1056/NEJMoa0907413. [DOI] [PubMed] [Google Scholar]
  • 18.Nolan T, McVernon J, Skeljo M, Richmond P, Wadia U, Lambert S, Nissen M. Immunogenicity of a monovalent 2009 influenza A(H1N1) vaccine in infants and children: a randomized trial. JAMA. 2010;303:37–46. doi: 10.1001/jama.2009.1911. [DOI] [PubMed] [Google Scholar]
  • 19.Plennevauz E, Blatter M, Reeves-Hoche MK, Denis M. Immune response after a single vaccination against 2009 influenza A H1N1 in USA: a preliminary report of report of two randomised controlled phase 2 trials. Lancet 2009 Dec 15. [Epub ahead of print] [DOI] [PubMed]
  • 20.Liang XF, Wang HQ, Wang JZ, Fang HH, Wu J, Zhu FC, Li RC. Safety and immunogenicity of 2009 pandemic influenza A H1N1 vaccines in China: a multicentre, double-blind, randomized, placebo-controlled trial. Lancet. 2010;375:56–66. doi: 10.1016/S0140-6736(09)62003-1. [DOI] [PubMed] [Google Scholar]
  • 21.Centers for Disease Control and Prevention (CDC) Safety of influenza A (H1N1) 2009 monovalent vaccines–United States, October 1–November 24, 2009. MMWR Morb Mortal Wkly Rep. 2009;58:1351–1356. [PubMed] [Google Scholar]
  • 22.Centers for Disease Control and Prevention (CDC) Serum cross-reactive antibody response to a novel influenza A (H1N1) virus after vaccination with seasonal influenza vaccine. MMWR Morb Mortal Wkly Rep. 2009;58:521–524. [PubMed] [Google Scholar]
  • 23.Greenbaum JA, Kotturi MF, Kim Y, Oseroff C, Vaughan K, Salimi N, Vita R. Pre-existing immunity against swine-origin H1N1 influenza viruses in the general human population. Proc Natl Acad Sci USA. 2009;106:20365–20370. doi: 10.1073/pnas.0911580106. [DOI] [PMC free article] [PubMed] [Google Scholar]
  • 24.Myers KP, Olsen CW, Setterquist SF, Capuano AW, Donham KJ, Thacker EL, Merchant JA. Are swine workers in the United States at increased risk of infection with zoonotic influenza virus? Clin Infect Dis. 2006;42:14–20. doi: 10.1086/498977. [DOI] [PMC free article] [PubMed] [Google Scholar]
  • 25.Chan YJ, Chen SD, Hsueh KH, Hsu NW, Perng CL, Chou NS, Tang GJ. Clinical manifestations of two cases with severe acute respiratory syndrome (SARS) in I-Lan county. J Chin Med Assoc. 2004;67:472–475. [PubMed] [Google Scholar]
  • 26.Chiang CH, Chen HM, Shih JF, Su WJ, Perng RP. Management of hospital-acquired severe acute respiratory syndrome with different disease spectrum. J Chin Med Assoc. 2003;66:328–338. [PubMed] [Google Scholar]
  • 27.Cao B, Li XW, Mao Y, Wang J, Lu HZ, Chen YS, Liang ZA. Clinical features of the initial cases of 2009 pandemic influenza A (H1N1) virus infection in China. N Engl J Med. 2009;361:2507–2517. doi: 10.1056/NEJMoa0906612. [DOI] [PubMed] [Google Scholar]

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