Jun.28,2007  42  US 2007/0148124 Al  interferon: microspectrophotometric quantitation of cyto› pathic effecf’,  Appln Environ. Microbial.,  31, 35-38, (1996),  the contents of which are incorporated by reference, was  used. The dose needed to reduce virus CPE by 50% (EC$_{50}$ )  is determined from this dye uptake. Compounds considered  active by CPE inhibition and by NR dye uptake were tested  again using a VY reduction assay. The effect on reduction of  virus yield was assessed by assaying frozen and thawed  eluates from each micro well for virus titer by serial dilution  onto monolayers ofMDCK cells. A known active drug is run  in parallel as a positive control. Since PSMA was found to  be a potent inhibitor of multiple strains of influenza in tissue  culture experiments, it was also tested against human strains  of virus adapted to grow in mice (strains NWS/33 and  Victoria/37/75 in Table 15).  [0365]  From the data obtained in the dose ranging study  above, three concentrations of PSMA were found to be  acceptable for dosing in an in vivo efficacy analysis, that is,  50 ul twice a day of PSMA at 0.3, 0.1 and 0.03 mg/ml.  [0366]  As used herein, unless indicated to the contrary, %  refers to percentage by weight. Unless indicated to the  contrary, the singular refers to the plural and vice versa.  [0367]  The above embodiments and examples are given to  illustrate the scope and spirit of the present invention. These  embodiments and examples will make apparent, to those  skilled in the art, other embodiments and examples. These  other embodiments and examples are within the contempla› tion of the present invention. Therefore the present invention  should be limited only by the appended claims.  We claim:  1.  A method for the treatment or prevention of a viral,  bacterial, or fungal infection in a host, which comprises  administering to the host a therapeutically or prophylacti› cally effective amount of an anionic cellulose-based poly› mer, a prodrug thereof, or a pharmaceutically acceptable salt  of said anionic cellulose based polymer or prodrug, wherein  [0364]  In vivo, in a dose fmding toxicity study efficacy  evaluation, PSMA was administered intranasally to mice  using the dose schedule shown in Table 16. In this study,  mice were dosed twice a day with 50 ul of test material for  five days, and then observed for a total of 21 days. The  results after 14 days are presented in Table 16.  *The different assay formats include cytopathic effect (CPE), virus yield reduction (VY)  and neutral red (NR) uptake.  * Survivors at day 14.  TABLE 15  Example 21  TABLE 16  Efficacy of PSMA Against Various Strains of Influenza Virus.  Virus  Strain  Assay*  EC$_{50 }$ wt%  EC$_{90 }$ wt% CC$_{90 }$wt%  HlNl  New Cal./20/99 VY  0.000018  HlNl  New Cal./20/99 CPE  <0.0000032  <0.01  H3N2  California/7 /04 VY  0.0001  H3N2  California/7 /04 CPE  0.00015  <0.01  HlNl  NR  <0.00007  0.05  HlNl  CPE  <0.00004  >0.04  H3N2  NR  <0.00004  >0.04  H3N2  CPE  <0.00007  >0.04  H5Nl  NR  <0.00009  0.053  H5Nl  CPE  <0.00004  >0.04  Flu B  NR  <0.00004  >0.04  Flu B  CPE  <0.00004  >0.04  HlNl  NWS/33  NR  <0.000031  0.042  HlNl  NWS/33  VY  <0.000031  HlNl  NWS/33  CPE  <0.000031  0.077  H3N2  Victoria/3/75  NR  0.000056  0.036  H3N2  Victoria/3/75  VY  0.000031  H3N2  Victoria/3/75  CPE  0.000043  0.077  Flu B  Sichuan/379/99 NR  <0.999931  0.033  Flu B  Sichuan/379/99 VY  0.000056  Flu B  Sichuan/379/99 CPE  <0.000031  0.077  TI  >556  >3125  >100  >67  >700  >1000  >1000  >1000  >588  >1000  >1000  >1000  >1355  >2485  >2485  643  2485  1790  >1065  1375  >2485  Maximum Tolerated Dose Following Intranasal Administration In Mice.  PSMA (mg/ul) Administered vol.  Regimen  Survivors*  Weight gain/loss  10 mg/ml  50 ul  2x a day for 5 days  0/3  3 mg/ml  50 ul  2x a day for 5 days  0/3  1 mg/ml  50 ul  2x a day for 5 days  0/3  0.3 mg/ml  50 ul  2x a day for 5 days  3/3  -1.5 gm at day 7  0.1 mg/ml  50 ul  2x a day for 5 days  3/3  -0.6 gm at day 7  0.03 mg/ml  50 ul  2x a day for 5 days  3/3  +0.2 gm at day 7 