This is one of the docs in the Pfizer hack from last night. It's European.

As of Nov 24th Pfizer were having batch integrity issues. The mRNA in use was not stable and subject to breaking down into two differing fragments. Out of five batches tested, one batch was 78% efficient, another 55% efficient. As the RNA integrity spec is >50% both were considered within acceptable parameters. Data was unavailable for the remaining two batches. This is one reason why the product has to be stored at such a low temperatures and must be used within a short time of defrosting. No safety studies have been conducted on mRNA integrity. This was considered a major obstacle and had to be addressed immediately (in other words, some batches contain mRNA fragments that are not approved for use and no safety study has been carried out). The second issue is impurities. They were found to be below the acceptable threshold in 4 out of 5 batches. The data for the acceptable batch was to be included in a future report and the purification process sorted out. Pfizer have no idea about product shelf-life. They guess 3-6 months, but will make it up as they go along.

Regarding the lipid nanoparticles - these degrade if they are subject to too much friction. Reason #2 for the storage temps. Upscaling the nanoparticle production process may cause quality issues. To be assessed by batch testing during rollout and fixed as rollout continues. There is no safety data on the chemicals used in the lipid nanoparticles. To be assessed during rollout.

Now we know why 2 x jabs: the mRNA integrity threshold is set at 50%.

As of the 24th Nov, there were 3 x MAJOR objections to European approval (all listed above). The UK approved on 2nd Dec.