That for now because it hasn't been tested. there have been no clinical trials with the mixing of pfizer, moderna, astrazeneca, and johnson & johnson. i will say, though, that although moderna has remained silent on this issue for now, they began clinical trials on whether or not a booster was needed months ago, when the uk variant first appeared. so we should be expecting to hear something along similar sentiment. if pfizer is truly seeing data that shows that immunity is waning and booster shots are needed, moderna is also an mrna vaccine. their data is likely to show the same. however, we d...