AZ Decision Review
Feb 26, 2021-Health Canada approves vaccine - no restrictions.
Mar 1, 2021 NACI (National Advisory Committee on Immunization) decision to place an age restriction up to age 64 on the AZ vaccine came from initial study trial data.
Real world data encompassing over 22 million people became available from countries that did not place an age restriction on the AZ vaccine, from which the data and they found the vaccine to be effective and safe.
Mar 16, 2021NACI changed its recommendation to provide that vaccine to the over 65 age group based on this data.
Mar 19 2021 Clotting (Thrombosis) and AZ vaccine.
Surveillance (monitoring) for significant side effects is standard with the introduction of any new vaccine.
During AZ monitoring, reports of a very small numbers of patients with clotting problems post AZ vaccine appeared (initially 35 or so... tracking ongoing) compared to the 22 million immunized with the vaccine to date. There were 35 cases and 3 deaths. 18 out of those 35 cases showed an extremely rare serious form of clotting (CVST = cerebral venous sinus thrombosis). CVST occurred at a higher frequency than would be expected from the literature. This is normally an extremely rare disorder affecting mostly women under the age of 55, many in the post delivery period. These events, however, occurred within 14 days of the AZ vaccinations.
The EMA (European Medicines Agency), an agency that monitors the safety of Medicines in the EU recognized the need to evaluate this data further, but concluded that the benefits of protecting against COVID-19 — which itself results in clotting problems — outweigh the risks. It also stated that it could not definitively rule out a link between the vaccine and specific, rare types of blood clots associated with, or low levels of blood platelets. They advised that anyone experiencing unusual bleeding, difficulty breathing or neurologic symptoms within 14 of vaccination should seek immediate medical assistance.
Many questions still remain. The science on this clotting pattern is unclear. The mechanism of this clotting is not yet known. Why these few individuals were so adversely affected - unknown.
Since then, the WHO, CDC, Public Health Canada and numerous Scientific Bodies have echoed that while there may be a causal link with the vaccine, it is not proven, and requires ongoing analysis.
Differences of opinion exist. Dr David Fisman, an epidemiologist at the University of Toronto, Dalla Lana School of Public Health, said publicly that the German data offered a "compelling picture”that the rare blood clots were potentially linked to the vaccine in rare cases. He feels restrictions on AZ vaccine use is needed. Some countries have chosen to suspend the use of AZ vaccine. Many others have continued immunizing with the AZ vaccine, agreeing that benefits outweigh risk.