The 38 SLIV programs occurred between November 4 and December 15, 2009. Each locality had between six and eight schools surveyed and program implementation characteristics were generally similar in each locality (). In each locality, SLIV programs occurred within a 2-d span. The mean number of enrolled students per school ranged from 394 to 763 across localities. The mean number of first doses administered in the SLIV programs varied by locality, ranging from 16 to 46 doses administered per 100 students. Schools in localities A–C administered on average significantly more doses per 100 students than localities E and F, which reported the lowest mean doses (p < 0.01, p < 0.01, p = 0.03 for A–C vs. E, respectively; p < 0.01, p < 0.01 and p < 0.05 for A–C vs. F, respectively; ).
In four localities (B–D and F), all programs were conducted during school hours with parental consent obtained in advance by distributing consent forms online, by mail, or by sending the forms home with children 7 to 61 d in advance of the program. In contrast, all programs in locality E were conducted after hours with parental consent obtained on-site. In locality A, four programs were conducting during school hours and four were conducted after school hours.
All localities used the H1N1 injectable and nasal spray vaccines. Use varied by locality, with three of six localities reporting predominant use of the nasal spray vaccine (range, 59% to 74% of vaccinations) and three of six localities reporting predominant use of injectable vaccine (range, 67% to 73%). Across individual SLIV programs, 87% (n = 33) of the SLIV programs used both vaccines, while 13% (n = 5) used only the injectable vaccine. The OIG report commented that “parental and staff misconceptions about the safety of the nasal mist” affected uptake in some localities. Vaccinations were offered free-of-charge to students.
Examination of program characteristics and uptake rates at the locality level suggested that program date was the principal factor associated with increased vaccination (). Programs conducted during the first week of November (locality A) administered more first doses than later programs. The mean number of doses per 100 students was 46 doses for the 8 programs in locality A, compared with 21 doses for the 30 later programs in other localities (p < 0.01).
Doses of H1N1 vaccine administered by program date and locality. Each school-located influenza vaccination program is represented by a single data point.
In addition to the increased uptake rate among programs conducted in early November, there appeared to be a general trend toward decreasing uptake rates across localities with increased time after November 1 (). The notable exception to this trend was locality E, which had a mean uptake rate that was significantly lower than that of localities C and B, whose SLIV programs also took place in mid- to late-November (means of 16 vs. 28 doses per 100 students, p = 0.05 and 16 vs. 30 doses per 100 students, p < 0.01, respectively). The most apparent difference in program characteristics between locality E and localities C and B was that all SLIV programs in locality E were conducted after school hours without advance parental consent; parental consent was obtained on-site on the day of the programs.
For other program characteristics evaluated, there were no other apparent associations in the available sample ().