https://www.publichealthontario.ca/-/media/documents/ncov/epi/covid-19-epi-confirmed-cases-post-vaccination.pdf?la=en Highlights Since the COVID-19 vaccination program began on December 14, 2020 and up to June 26, 2021, a total of 9,864,684 individuals in Ontario received at least one dose of vaccine (Table 2). Of the almost 9.9 million vaccinated individuals only 0.16% (15,592 individuals including both symptomatic and asymptomatic cases) became infected when they were partially vaccinated and only 0.02% (1,635 individuals) became infected when they were fully vaccinated; as these were fully vaccinated individuals, these are considered breakthrough cases (Table 2). The majority (51.7%) of post-vaccination cases identified were not yet protected from vaccination when they acquired their infection, as their symptom onset date was within 0 to <14 days following dose 1 administration (Table 1). The number of post-vaccination cases declines dramatically as time from vaccination increases. The number of post-vaccination cases appears to decrease at about 10 days after dose 1. A marked decrease in post-vaccination cases is observed 28 or more days after dose 1 and very few cases are reported following dose 2 (Figure 1). Only 4.6% of cases post-vaccination occurred 14 or more days after dose 2 administration and are considered breakthrough cases (Table 1). Trends in partially vaccinated and breakthrough cases are a reflection of both trends in vaccine administration (increasing number of doses administered over time) and trends in COVID-19 incidence (Figure 2a and 2b). 总体防疫形势不错，但是一个有趣的现象是Figure 2b如果把number of case 转成percentage的话，突破率百分比近期似乎随着总case的减少而增加，当然这可以从各种不同角度来诠释（a.k.a.臆测 ）。
Highlights Since the COVID-19 vaccination program began on December 14, 2020 and up to June 26, 2021, a total of 9,864,684 individuals in Ontario received at least one dose of vaccine (Table 2).
Of the almost 9.9 million vaccinated individuals only 0.16% (15,592 individuals including both symptomatic and asymptomatic cases) became infected when they were partially vaccinated and only 0.02% (1,635 individuals) became infected when they were fully vaccinated; as these were fully vaccinated individuals, these are considered breakthrough cases (Table 2).
The majority (51.7%) of post-vaccination cases identified were not yet protected from vaccination when they acquired their infection, as their symptom onset date was within 0 to <14 days following dose 1 administration (Table 1).
The number of post-vaccination cases declines dramatically as time from vaccination increases. The number of post-vaccination cases appears to decrease at about 10 days after dose 1. A marked decrease in post-vaccination cases is observed 28 or more days after dose 1 and very few cases are reported following dose 2 (Figure 1).
Only 4.6% of cases post-vaccination occurred 14 or more days after dose 2 administration and are considered breakthrough cases (Table 1).
Trends in partially vaccinated and breakthrough cases are a reflection of both trends in vaccine administration (increasing number of doses administered over time) and trends in COVID-19 incidence (Figure 2a and 2b).
总体防疫形势不错，但是一个有趣的现象是Figure 2b如果把number of case 转成percentage的话，突破率百分比近期似乎随着总case的减少而增加，当然这可以从各种不同角度来诠释（a.k.a.臆测 ）。