This is potentially the answer for total global vaccination. It is an inactivated virus vaccine produced using conventional chicken egg technology, and does not require state-of-the-art high technology manufacturing like the mRNA and viral vector vaccines.
The twist is it uses the Newcastle Disease avian virus genetically re-engineered to express the SARS-CoV-2 spike protein with six proline substitutions to facilitate locking it in an open pre-fusion state for maximal exposure of the RBD region. This makes its spike much more sophisticated than the spikes currently in use by our advanced vaccines.
It should be a very effective vaccine.
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Their COVID related news should be open access.