Table 3 Multiple linear regression for HCWs full vaccination coverage during the period February to June 2021 (n = 115 countries)

World Bank income groups

 LIC

ref

 LMIC

12.4 (-8.2; 33.0)

 UMIC

9.3 (-18.2; 36.9)

 HIC

9.6 (-28.3; 47.4)

Vaccines doses availability (% of the vaccination-eligible population)^a

  < 40%

ref

 40% to 69%

15.5 (-3.9; 34.9)

  ≥ 70%

35.9 (15.1; 56.9)

Out-of-pocket health expenditure (OPHE) per capita (US$)^a

  < 100

ref

 100 to 499

12.6 (-9.4; 34.5)

  ≥ 500

25.0 (-6.4; 56.4)

Nursing personnel density (per 10,000 population)^a

  < 30

ref

 30 to 60

-10.4 (-29.6; 8.6)

  > 60

-9.4 (-32.2; 13.4)