बेफोर भाइरासफोरा दिदोमै सोलायनाय , दिहुननाय , जायफोरखौ खाव - बाहागोफोर एबा फोलेरफोर बुङो , बेफोरो थार भाइरासनिफ्राय जुदा नाथाय बेनि आखुथायफोरनि माखासे थायो ।
These viruses are constantly changing producing what are called subtypes or strains that are different from the original virus but retain some of its characteristics .