Fig 1.
The virus, V, attacks target cells, T, at rate β. Once infected, target cells enter the eclipse phase, E. The eclipse phase lasts an average time of τE, after which the cells become infectious cells, I. The infectious cells produce new virions at rate p, and the virus decays at rate c. The cells remain infectious for an average time of τI, after which they die.
Fig 2.
In vitro RSV and influenza virus infection data used in this study.
Table 1.
Data sets used in this study.
Fig 3.
Empirical and viral kinetics model fits.
We fit both the empirical model (Eq (1)) and the viral kinetics model (Eq (2)) to each of the RSV and influenza virus viral time courses. The best fit curves are shown in Fig 3 where the red dashed line represents the best fit empirical model and the blue solid line represents the best fit viral kinetics model. The extracted parameter values are presented in Table 2 for the empirical model and in Table 3 for the viral kinetics model.
Fig 4.
Comparison of empirical model parameters.
Graphs show the distributions of (a) growth rate, (b) decay rate, (c) time to peak viral titer estimated from fits of the empirical model for RSV and the different strains of influenza virus. Statistically significant differences (p < 0.05) between RSV and a particular influenza virus strain are indicated with an asterisk. The p-values for the Mann-Whitney test are given in Table 4. Median values are indicated with a solid black line.
Table 2.
Estimated parameter values for the empirical model (Eq (1)).
Fig 5.
Comparison of viral kinetics parameters.
Graphs show the distributions of (a) infecting time (tinf), (b) duration of the infectious phase (τI), (c) duration of the eclipse phase (τE), and (d) degradation rate (c) estimated from fits of the gamma model for RSV and the different strains of influenza virus. Statistically significant differences (p < 0.05) between RSV and a particular influenza virus strain are indicated with an asterisk. The p-values for the Mann-Whitney test are given in Table 4. Median values are indicated with a solid black line.
Fig 6.
Differences in infection time course.
(a) Predicted time courses of RSV, pH1N1, PR8, WSN33 MDCK, and WSN33 MDBK using the median values (Table 3) for each of the parameters in the viral kinetics model (Eq (2)). (b) A schematic diagram of the duration of different phases (using median values) of the viral replication cycle for RSV, pH1N1, PR8, WSN33 MDCK, and WSN33 MDBK.
Table 3.
Estimated parameter values for the viral kinetics model (Eq (2)).
Table 4.
Results of the Mann-Whitney tests (p-values).