  In a recent paper, we investigated possible systematic uncertainties related
to the Cepheid color-luminosity calibration method and their influence on the
tension between the Hubble constant as inferred from distances to Type Ia
supernovae and the cosmic microwave background as measured with the Planck
satellite. Here, we study the impact of other sources of uncertainty in the
supernova distance ladder, including Cepheid temperature and metallicity
variations, supernova magnitudes and GAIA parallax distances. Using Cepheid
data in 19 Type Ia supernova host galaxies from Riess et al (2016), anchor data
from Riess et al (2016, 2019, 2021) and a set of re-calibrated Milky Way
Cepheid distances, we obtain $H_0 = 71.9\pm 2.2$ km/s/Mpc, $2.0\,\sigma$ from
the Planck value. Excluding Cepheids with estimated color excesses
$\hat{E}({\rm V} - {\rm I})=0.15$ mag to mitigate the impact of the Cepheid
color-luminosity calibration, the inferred Hubble constant is $H_0 = 68.1\pm
2.6$ km/s/Mpc, removing the tension with the Planck value.
