Volume 19, Number 3—March 2013
Effects of Vaccine Program against Pandemic Influenza A(H1N1) Virus, United States, 2009–2010
||No. persons vaccinated
||Estimated doses by population subgroup†
|Age 6 mo–9 y
||Age 10–24 y
||Pregnant, Age 18–64 y§
||Age 25–64 y
||Age >65 y
||HCW, non-HR, NP
||Contact with children <6 mo, non-HCW, non-HR, NP
||No contact with children <6 mo, non-HCW, non-HR, NP
|40||2009 Oct 10||2,971,000||2,971,000||836,000||0||578,000||171,000||314,000||283,000||69,000||363,000||358,000|
|41||2009 Oct 17||6,536,000||6,536,000||1,838,000||0||1,272,000||376,000||690,000||622,000||151,000||799,000||788,000|
|42||2009 Oct 24||10,993,000||10,993,000||3,091,000||0||2,139,000||633,000||1,161,000||1,046K||254K||1,343K||1,325K|
|43||2009 Oct 31||17,826,000||17,944,000||5,013,000||119,000||3,469,000||1,026,000||1,882,000||1,696,000||412,000||2,178,000||2,148,000|
|44||2009 Nov 7||23,755,000||24,239,000||6,526,000||483,000||4,776,000||1,230,000||2,467,000||2,275,000||573,000||3,116,000||2,790,000|
|45||2009 Nov 14||29,684,000||30,533,000||8,040,000||848,000||6,084,000||1,435,000||3,053,000||2,853,000||734,000||4,054,000||3,433,000|
|46||2009 Nov 21||35,613,000||36,827,000||9,553,000||1,213,000||7,391,000||1,639,000||3,638,000||3,431,000||895,000||4,991,000||4,075,000|
|47||2009 Nov 28||41,543,000||43,121,000||11,067,000||1,578,000||8,698,000||1,843,000||4,223,000||4,009,000||1,056,000||5,929,000||4,717,000|
|48||2009 Dec 5||45,427,000||47,709,000||11,837,000||2,282,000||9,511,000||1,911,000||4,717,000||4,275,000||1,146,000||6,799,000||5,231,000|
|49||2009 Dec 12||49,311,000||52,297,000||12,608,000||2,985,000||10,325,000||1,978,000||5,211,000||4,540,000||1,235,000||7,669,000||5,745,000|
|50||2009 Dec 19||53,196,000||56,885,000||13,379,000||3,689,000||11,138,000||2,045,000||5,705,000||4,805,000||1,325,000||8,539,000||6,259,000|
|51||2009 Dec 26||57,080,000||61,473,000||14,150,000||4,393,000||11,952,000||2,112,000||6,199,000||5,071,000||1,414,000||9,409,000||6,773,000|
|52||2010 Jan 3||59,526,000||64,388,000||14,541,000||4,862,000||12,406,000||2,171,000||6,480,000||5,217,000||1,463,000||10,031,000||7,217,000|
|1||2010 Jan 10||61,972,000||67,304,000||14,931,000||5,332,000||12,860,000||2,230,000||6,760,000||5,364,000||1,513,000||10,653,000||7,661,000|
|2||2010 Jan 17||64,417,000||70,219,000||15,322,000||5,802,000||13,313,000||2,289,000||7,040,000||5,510,000||1,562,000||11,275,000||8,105,000|
|3||2010 Jan 24||66,863,000||73,134,000||15,713,000||6,271,000||13,767,000||2,349,000||7,320,000||5,657,000||1,611,000||11,897,000||8,550,000|
|4||2010 Jan 31||69,309,000||76,050,000||16,103,000||6,741,000||14,221,000||2,408,000||7,601,000||5,803,000||1,660,000||12,519,000||8,994,000|
|5||2010 Feb 7||70,924,000||77,979,000||16,353,000||7,055,000||14,489,000||2,408,000||7,846,000||5,863,000||1,702,000||12,999,000||9,263,000|
|6||2010 Feb 14||72,539,000||79,907,000||16,603,000||7,369,000||14,757,000||2,408,000||8,092,000||5,924,000||1,745,000||13,479,000||9,532,000|
|7||2010 Feb 21||74,154,000||81,836,000||16,852,000||7,683,000||15,025,000||2,408,000||8,338,000||5,984,000||1,787,000||13,959,000||9,802,000|
|8||2010 Feb 28||75,769,000||83,765,000||17,102,000||7,997,000||15,293,000||2,408,000||8,583,000||6,044,000||1,829,000||14,438,000||10,071,000|
|9||2010 Mar 7||76,480,000||84,633,000||17,196,000||8,153,000||15,386,000||2,408,000||8,713,000||6,090,000||1,874,000||14,613,000||10,200,000|
|10||2010 Mar 14||77,192,000||85,501,000||17,291,000||8,309,000||15,478,000||2,408,000||8,842,000||6,137,000||1,920,000||14,788,000||10,328,000|
|11||2010 Mar 21||77,903,000||86,369,000||17,386,000||8,465,000||15,570,000||2,408,000||8,971,000||6,184,000||1,965,000||14,963,000||10,456,000|
|12||2010 Mar 28||78,615,000||87,236,000||17,481,000||8,622,000||15,662,000||2,408,000||9,101,000||6,230,000||2,010,000||15,138,000||10,585,000|
|13||2010 Apr 4||78,943,000||87,680,000||17,536,000||8,737,000||15,743,000||2,408,000||9,144,000||6,239,000||2,017,000||15,207,000||10,649,000|
|14||2010 Apr 11||79,272,000||88,124,000||17,592,000||8,852,000||15,824,000||2,408,000||9,188,000||6,247,000||2,024,000||15,276,000||10,713,000|
|15||2010 Apr 18||79,600,000||88,568,000||17,648,000||8,968,000||15,905,000||2,408,000||9,232,000||6,255,000||2,030,000||15,345,000||10,778,000|
*Monthly estimates, by population subgroups, are from the National 2009 H1N1 Flu Survey (NHFS) and the Behavioral Risk Factor Surveillance System survey (4,9,10,14,16,28). Estimates were benchmarked to final season monthly estimates for available age and target groups (9). Adjustments were made to overall population counts and the number of persons vaccinated to account for limitations in either dataset. The distribution of weekly and monthly numbers of persons vaccinated were obtained from the survey data. HR, high risk; NP, not pregnant; HCW, health care worker; Contact, household contacts and caregivers of children <6 mo of age.
†Weekly estimates were made by examining overall National 2009 H1N1 Flu Survey weekly vaccination numbers and by using the same distribution to estimate the first 3 weeks of data. For all other weeks, data were estimated by using linear interpolation between point estimates at the start and end of each month.
‡Weeks during which influenza activity was reported during 2009–10 influenza reporting period; 40 –52 indicates last 12 weeks of 2009, and 1–15 indicates first 15 weeks of 2010.
§Estimated number of pregnant women from survey data was considered an underestimation because of the definition of pregnant women and low sample size. Therefore, the total number of pregnant women vaccinated during the course of the pandemic was based on data from Moro et al (18). Because the cohort of pregnant women changed during the influenza season, analysis for this group was restricted to NHFS interviews conducted April 4, 2010–Jun 30, 2010. During this time, a new question, “Were you pregnant at any time October 2009 through January 2010?” was added to the NHFS for women 18–64 y to include those pregnant during the major vaccination period. Because no information was available on vaccinations among pregnant women after January, we assumed no further vaccinations were administered, an approach that could have underestimated the effects of A(H1N1)pdm09 virus vaccination on pregnant women.
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1Current affiliation: Merck & Co., Inc., Lansdale, Pennsylvania, USA.