Table 2.
Summary of population size, influenza-associated hospitalization rates, influenza-associated death rates, vaccine efficacy, potential hospitalizations averted per 100,000 vaccinated, potential deaths averted per 100,000 vaccinated, and vaccine coverage by high risk group, South Africa.
| Risk group | Mid-year population in South Africa (2016) | Age and HIV-standardized rate of influenza-associated hospitalization per 100,000 person years (95% CI) | Age and HIV-standardized rate of influenza-associated death per 100,000 person years (95% CI) | Vaccine efficacy* in risk group | Potential hospitalizations averted per 100,000 vaccinated (95% CI) | Potential deaths averted per 100,000 vaccinated (95% CI) | Vaccine coverage** |
|---|---|---|---|---|---|---|---|
| Pregnant women | 1,198,861 (births) 270,235 HIV-infected (22.5%) |
378.8 (237.7–534.8) | 12.6 (7.2–18.0) | 61% (95% CI, 43–73%) n = 6430 | 228.5 (130.8–362.4) 27.8 (15.3–40.6)*** |
7. 7(3.9–12.0) 7.8 (5.1–10.7)*** |
14% Tetanus toxoid 2 dose coverage 80% in 2015 |
| HIV-infected adults aged 15–64 years | 6,604,709 | 256.3 (179.4–333.2) | 64.7 (38.3–81.1) | 76% (95% CI, 9–96%), n = 506 | 190.9 (24.5–390.6) | 48.2 (6.1–102.3) | 3% |
| Children aged 6–23 months | 1,729,502 15,911 HIV-infected (0.9%) |
324.1 (237.6 – 417.8) | 23.4 (5.1 – 26.5) | 35% (95% CI, −41–70%), n = 1893 | 111.6 (1.1 – 238.3) | 8.0 (0.1–18.3) | 3% Measles vaccine 2 dose coverage 63% in 2015 |
| Adults aged ≥ 65 years | 2,909,122 97,640 HIV-infected (3.36%) |
194 (144–256) | 169.3 (81.0–324.6) | 58% (95% CI, 40–70%), n = 11,848 | 111.0 (70.3 – 160.7) | 96.6 (26.2–180.9) | 2% |
| Healthcare workers | 566,393 88,924 HIV-infected (15.7%) |
60.6 (45.5 – 75.8) | 20.9 (9.4–29.0) | 60% (95% CI, 53–66%), n = 51,724 | 36.1 (26.5–46.3) | 12.5 (6.6–18.7) | 10% |
| Adults and children with TB (all ages) | 318,193 notified cases in 2014 ( ≥ 60% HIV-infected) | 282.7 (193.5–377.4) | 164 (144–174) | Unknown; used estimate in elderly 58% (95% CI, 40–70%), n = 11,848 | 162.0 (96.6 – 245.1) | 95.0 (64.0 – 127.3) | 3% |
| Adults and children aged 5–64 years with other chronic illnesses | 9,863,353 | 42.4 (31.8 – 53.7) | 24.4 (15.4 – 35.3) | Unknown; used estimate in elderly 58% (95% CI, 40–70%), n = 11,848 | 29.4 (15.5 – 44.7) | 16.7 (8.3–28.3) | 3% |
*
Against laboratory-confirmed influenza-associated illness.
**
2015 national estimates for all risk groups except healthcare workers.
***
Due to timing of maternal vaccination only 8–10% of burden in infants may be averted (M. Biggerstaff, in preparation).