Looking at this topic from the point of view of, "Why Peru?", Peru has has had an "outbreak" of GBS ... but the US has not, and the UK (a heavy user of the Oxford-AZ vaccine) has not. Why is Peru different?
1. Not directly related, but relevant to the OP article, per
https://en.wikipedia.org/wiki/COVID-19_vaccination_in_Peru , the vaccination rate in Peru is more like 62%, not the 84% the OP article claims. In the context of statistics manipulation and pretzellation by anti-Covid-vax sources, exaggerating the vaccination rate from 62% to 84% is pretty small potatoes, though unsurprising.
2. More to the point above, Peru has made significant use of two vaccines not used in the US or UK, Sinopharm's and the Sputnik V. To give context to that fact and to my post above, here are the four vaccine technologies in use in the world,
the oldest first and the newest last:
- Protein sub-unit; for example, Novavax's Covid vaccine;
- Dead or inactive virus; for example, Sinopharm's and Sinovax's Covid vaccines;
- Viral vector; for example, Oxford-AZ, Janssen-J&J, and Sputnik V Covid vaccines
- mRNA; for example, Pfizer and Moderna Covid vaccines.
Since the US and UK heavily used Pfizer and Moderna, and Oxford-AZ and have not had a GBS "outbreak", that indicates that
if Peru's "outbreak" is related to a Covid vaccine, the likely culprit(s) would be the Russian Sputnik V or/and the Chinese Sinopharm.
OTOH, Peru has substantial rainforest area from which tropical diseases could spread and a less than robust healthcare system. IOW, Peru's GBS "outbreak" could be related to a disease outbreak rather than Covid vaccines.