If there are indeed different strains, then it will make vaccine manufacture more complex. What is not mentioned there, but might be relevant is that Germany, the UK and NY have reported some COVID-19 infected children also suffering a toxic shock syndrome type condition as well. So are such cases being reported on the west coast of the US? If they aren't does it support the argument for different strains? And if so, what is so different about the European strain that it causes such toxic shock syndrome type symptoms in children?