ks - the study showing stronger side effects with mixed vaccines was the UK com-cov study, where the 2 shots were given 4 weeks apart. In german studies where the 2 shots were given 9 weeks apart, this enhancement of side effects was not seen.
Most of the published studies on mixing vaccines have been with astrazenica and pfizer. I've not seen pfizer/moderna mixes, but I admit I stopped following the literature after I was done with my shots. .
We are now allowed to go as soon as 28 days apart for the 3rd shot. Some of us are at the 6-8 month mark already.
FDA/CDC guidance is to try to stick to your original manufacture if you had Pfizer or Moderna. If you had a J&J shot then you should get Pfizer.
I’m not sure how I feel about
developed countries putting their entire population ahead of the less developed countries around the world. I understand the sick, the elderly, and healthcare workers getting boosters if the scientists think it is necessary. But these recent variants developed in India, South Africa and Peru are becoming problematic for the entire world. They’ve only produced 1/3-1/4 of the necessary vaccines that we need in the world. Putting already vaccinated populations ahead of the devolving world could be a huge mistake and ethically dubious.