2009 swine flu pandemic vaccine

The 2009 swine flu pandemic vaccines were influenza vaccines developed to protect against the pandemic H1N1/09 virus. These vaccines either contained inactivated (killed) influenza virus, or weakened live virus that could not cause influenza. The killed virus was injected, while the live virus was given as a nasal spray. Both these types of vaccine were produced by growing the virus in chicken eggs. Around three billion doses were produced, with delivery in November 2009.^[1]^[2]^{[needs update]}

In studies, the vaccine^[which?] appeared both effective and safe,^[3]^[4]^[5]^[6]^[7]^[8]^[9]^[10] providing a strong protective immune response and having a similar safety profile to the usual seasonal influenza vaccine.^[11] However, about 30% of people already had some immunity to the virus, with the vaccine conferring greatest benefit on young people, since many older people are already immune through exposure to similar viruses in the past.^[12] The vaccine also provided some cross-protection against the 1918 flu pandemic strain.^[13]

Early results (pre-25 December 2009) from an observational cohort of 248,000 individuals in Scotland showed the vaccine to be effective at preventing H1N1 influenza (95.0% effectiveness [95% confidence intervals 76.0–100.0%]) and influenza-related hospital admissions (64.7% [95% confidence intervals 12.0–85.8%]).^[14]

Developing, testing, and manufacturing sufficient quantities of a vaccine is a process that takes many months. According to Keiji Fukuda of the World Health Organization, "There's much greater vaccine capacity than there was a few years ago, but there is not enough vaccine capacity to instantly make vaccines for the entire world's population for influenza."^[15] The nasal mist version of the vaccine started shipping on 1 October 2009.^[16]^{[needs update]}

^ "WHO cuts swine flu vaccine production estimate". AFP. 24 September 2009. Archived from the original on 6 February 2010. Retrieved 25 November 2009.
^ "Transcript of virtual press conference with Gregory Hartl, Spokesperson for H1N1, and Dr Marie-Paule Kieny, WHO Director of the Initiative for Vaccine Research, World Health Organization" (PDF) (Press release). World Health Organization. 24 September 2009. Archived (PDF) from the original on 28 August 2010. Retrieved 13 August 2010.
^ Wu J, Xu F, Lu L, Lu M, Miao L, Gao T, et al. (December 2010). "Safety and effectiveness of a 2009 H1N1 vaccine in Beijing". The New England Journal of Medicine. 363 (25): 2416–2423. doi:10.1056/NEJMoa1006736. PMID 21158658. S2CID 205092379.
^ Centers for Disease Control and Prevention (CDC) (December 2009). "Safety of influenza A (H1N1) 2009 monovalent vaccines - United States, October 1-November 24, 2009" (PDF). MMWR. Morbidity and Mortality Weekly Report. 58 (48): 1351–1356. PMID 20010511. Archived (PDF) from the original on 25 June 2017. Retrieved 8 September 2017.
^ Van der Vliet D, Pepin S, Lambert M, Fauchoux N, Donazzolo Y, Dupuy M, et al. (October 2010). "Similar immunogenicity of the A/H1N1 2009 pandemic influenza strain when used as a monovalent or a trivalent vaccine". Human Vaccines. 6 (10): 823–828. doi:10.4161/hv.6.10.13600. PMID 20935517. S2CID 20297275.
^ Simpson CR, Ritchie LD, Robertson C, Sheikh A, McMenamin J (September 2012). "Effectiveness of H1N1 vaccine for the prevention of pandemic influenza in Scotland, UK: a retrospective observational cohort study". The Lancet. Infectious Diseases. 12 (9): 696–702. doi:10.1016/S1473-3099(12)70133-0. PMID 22738894. S2CID 19702558.
^ Valenciano M, Kissling E, Cohen JM, Oroszi B, Barret AS, Rizzo C, et al. (January 2011). Simonsen L (ed.). "Estimates of pandemic influenza vaccine effectiveness in Europe, 2009-2010: results of Influenza Monitoring Vaccine Effectiveness in Europe (I-MOVE) multicentre case-control study". PLOS Medicine. 8 (1): e1000388. doi:10.1371/journal.pmed.1000388. PMC 3019108. PMID 21379316.
^ "2009 H1N1 vaccine safe and induces robust immune response in people with asthma" (Press release). National Institutes of Health (NIH). 13 December 2010. Archived from the original on 4 January 2011. Retrieved 29 January 2011.
^ Busse WW, Peters SP, Fenton MJ, Mitchell H, Bleecker ER, Castro M, et al. (January 2011). "Vaccination of patients with mild and severe asthma with a 2009 pandemic H1N1 influenza virus vaccine". The Journal of Allergy and Clinical Immunology. 127 (1): 130–137, 137.137–3. doi:10.1016/j.jaci.2010.11.014. PMC 3017653. PMID 21145578.
^ Liang XF, Li L, Liu DW, Li KL, Wu WD, Zhu BP, et al. (February 2011). "Safety of influenza A (H1N1) vaccine in postmarketing surveillance in China". The New England Journal of Medicine. 364 (7): 638–647. doi:10.1056/NEJMoa1008553. PMID 21288090. S2CID 23923166.
^ Grady D (5 December 2009). "Review Shows Safety of H1N1 Vaccine, Officials Say". The New York Times. Archived from the original on 6 September 2015. Retrieved 23 December 2010. No substantial differences between H1N1 and seasonal influenza vaccines were noted in the proportion or types of serious adverse events reported.
^ Cite error: The named reference ap01 was invoked but never defined (see the help page).
^ Fox M (16 June 2010). "Swine flu shot protects against 1918 flu: study". Reuters. Archived from the original on 18 June 2010. Retrieved 17 June 2010.
^ Simpson CR, Ritchie LD, Robertson C, Sheikh A, McMenamin J (July 2010). "Vaccine effectiveness in pandemic influenza - primary care reporting (VIPER): an observational study to assess the effectiveness of the pandemic influenza A (H1N1)v vaccine". Health Technology Assessment. 14 (34): 313–346. doi:10.3310/hta14340-05. PMID 20630126.
^ "Preparing for the worst". The Financial Express. 8 May 2009. Archived from the original on 27 March 2020. Retrieved 6 December 2009.
^ "First round of swine flu vaccine shipped to Texas, other states". The Dallas Morning News. 1 October 2009. Archived from the original on 4 October 2009. Retrieved 1 October 2009.

[AFP_WHO20090924-1] "WHO cuts swine flu vaccine production estimate". AFP. 24 September 2009. Archived from the original on 6 February 2010. Retrieved 25 November 2009.

[WHO20090924-2] "Transcript of virtual press conference with Gregory Hartl, Spokesperson for H1N1, and Dr Marie-Paule Kieny, WHO Director of the Initiative for Vaccine Research, World Health Organization" (PDF) (Press release). World Health Organization. 24 September 2009. Archived (PDF) from the original on 28 August 2010. Retrieved 13 August 2010.

[3] Wu J, Xu F, Lu L, Lu M, Miao L, Gao T, et al. (December 2010). "Safety and effectiveness of a 2009 H1N1 vaccine in Beijing". The New England Journal of Medicine. 363 (25): 2416–2423. doi:10.1056/NEJMoa1006736. PMID 21158658. S2CID 205092379.

[4] Centers for Disease Control and Prevention (CDC) (December 2009). "Safety of influenza A (H1N1) 2009 monovalent vaccines - United States, October 1-November 24, 2009" (PDF). MMWR. Morbidity and Mortality Weekly Report. 58 (48): 1351–1356. PMID 20010511. Archived (PDF) from the original on 25 June 2017. Retrieved 8 September 2017.

[5] Van der Vliet D, Pepin S, Lambert M, Fauchoux N, Donazzolo Y, Dupuy M, et al. (October 2010). "Similar immunogenicity of the A/H1N1 2009 pandemic influenza strain when used as a monovalent or a trivalent vaccine". Human Vaccines. 6 (10): 823–828. doi:10.4161/hv.6.10.13600. PMID 20935517. S2CID 20297275.

[6] Simpson CR, Ritchie LD, Robertson C, Sheikh A, McMenamin J (September 2012). "Effectiveness of H1N1 vaccine for the prevention of pandemic influenza in Scotland, UK: a retrospective observational cohort study". The Lancet. Infectious Diseases. 12 (9): 696–702. doi:10.1016/S1473-3099(12)70133-0. PMID 22738894. S2CID 19702558.

[I-MOVE-7] Valenciano M, Kissling E, Cohen JM, Oroszi B, Barret AS, Rizzo C, et al. (January 2011). Simonsen L (ed.). "Estimates of pandemic influenza vaccine effectiveness in Europe, 2009-2010: results of Influenza Monitoring Vaccine Effectiveness in Europe (I-MOVE) multicentre case-control study". PLOS Medicine. 8 (1): e1000388. doi:10.1371/journal.pmed.1000388. PMC 3019108. PMID 21379316.

[8] "2009 H1N1 vaccine safe and induces robust immune response in people with asthma" (Press release). National Institutes of Health (NIH). 13 December 2010. Archived from the original on 4 January 2011. Retrieved 29 January 2011.

[9] Busse WW, Peters SP, Fenton MJ, Mitchell H, Bleecker ER, Castro M, et al. (January 2011). "Vaccination of patients with mild and severe asthma with a 2009 pandemic H1N1 influenza virus vaccine". The Journal of Allergy and Clinical Immunology. 127 (1): 130–137, 137.137–3. doi:10.1016/j.jaci.2010.11.014. PMC 3017653. PMID 21145578.

[pmid21288090-10] Liang XF, Li L, Liu DW, Li KL, Wu WD, Zhu BP, et al. (February 2011). "Safety of influenza A (H1N1) vaccine in postmarketing surveillance in China". The New England Journal of Medicine. 364 (7): 638–647. doi:10.1056/NEJMoa1008553. PMID 21288090. S2CID 23923166.

[NYT_GRADY-11] Grady D (5 December 2009). "Review Shows Safety of H1N1 Vaccine, Officials Say". The New York Times. Archived from the original on 6 September 2015. Retrieved 23 December 2010. No substantial differences between H1N1 and seasonal influenza vaccines were noted in the proportion or types of serious adverse events reported.

[ap01-12] Cite error: The named reference ap01 was invoked but never defined (see the help page).

[cross-protection-13] Fox M (16 June 2010). "Swine flu shot protects against 1918 flu: study". Reuters. Archived from the original on 18 June 2010. Retrieved 17 June 2010.

[14] Simpson CR, Ritchie LD, Robertson C, Sheikh A, McMenamin J (July 2010). "Vaccine effectiveness in pandemic influenza - primary care reporting (VIPER): an observational study to assess the effectiveness of the pandemic influenza A (H1N1)v vaccine". Health Technology Assessment. 14 (34): 313–346. doi:10.3310/hta14340-05. PMID 20630126.

[Economist-15] "Preparing for the worst". The Financial Express. 8 May 2009. Archived from the original on 27 March 2020. Retrieved 6 December 2009.

[16] "First round of swine flu vaccine shipped to Texas, other states". The Dallas Morning News. 1 October 2009. Archived from the original on 4 October 2009. Retrieved 1 October 2009.

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