Sawyer now makes a filter, or should I say purifier, that will remove viruses without the use of chemicals. They also claim an approximate purifier filter life of 3000 gallons. I've been considering purchasing one for several weeks now. I can't find anyone who has tried them out. I believe they are pretty new to the market.
The second link below has more information and also has a link to videos.
The price of the SP135 Purifier Kit shows to be $122.90 on Sawyers website but I found them for $79.00 at Moontrail.com


Sawyer Viral Purifiers

Just Drink

smitty