  In recent years, evidence has accumulated that some high-energy cosmic
neutrinos can be associated with blazars. The strongest evidence for an
individual association was found in the case of the blazar TXS 0506+056 in
2017. In July 2019, another track-like neutrino event (IC190730A) was found
spatially coincident with the well-known bright flat-spectrum radio quasar PKS
1502+106. PKS 1502+106 was not found to be in a particularly elevated gamma-ray
state, but exhibited a remarkably bright radio outburst at the time of the
neutrino detection, similar to TXS 0506+056. We have performed a
multi-frequency VLBI study from 15 GHz up to 86 GHz on TXS 0506+056, PKS
1502+106 and one additional neutrino-candidate blazar (PKS 0215+015) to study
the radio structure of neutrino candidate blazars in response to their neutrino
association. We have obtained target of opportunity observations with the VLBA
for all three sources within $\sim$1 month from their associated neutrino
events and are performing multi-epoch studies of the jet kinematics at 15 GHz
as part of the MOJAVE program. Here, we present first results on TXS 0506+056
at 86 GHz and one additional 43 GHz image obtained 27 days after IC170922A,
closer in time to the neutrino event than previously published images. We also
give an overview about our recent work on PKS 1502+106 and PKS 0215+015.
