COVID-19 Modelling Indian data (Part 2)

COVID-19 infection in India: SIR simulation and Prediction (Part 2)

I hope that you liked the first part. If you have not read the first part, you should read that before reading this post. 
So, we have already completed modelling and prediction for stage 2. It was interesting to note that we could not see much difference in the model at stage 2 compared to stage 1. If lock-down worked, we would expect to see some of its impact in stage 3.

let's start with stage 3

3) Stage3: third and fourth weeks after lock-down

# April 08 to April 22

start_date <- "2020-04-08"

end_date <- "2020-04-22"

After modelling, there was a clear impact of lock-down at this stage. The R0 value dropped down to around 1. (details not shown). Let's only look at the graph first.

The prediction plot below now clearly shows the flattening of the infection curve. This is the effect of lock-down. To make clearly visible, the graph is also given in logarithmic scale. The model still predicts that 10,000,000 people will be infected during the peak time, if further improvements does not occur.

Now, the current stage 4,

4) Stage4: fifth and sixth weeks after lockdown

# April 21 to May 01

start_date <- "2020-04-21"

end_date <- "2020-05-01"

The effect of lock-down remains and the value of R0 drops to around 1.

The prediction plot below now clearly shows the flattening of the infection curve. Lock-down continues to keep the impact. To make it clearly visible, the graph is also given in logarithmic scale. The model still predicts that around 1,000,000 people will be infected during the peak time, if a further improvement does not occur. This prediction is 10 times lower than the prediction based on data from previous weeks (stage 3). Since lock-down continues further for two weeks, the peak number is likely to be flattened more. Hence, less than 100,000 people are likely to be infected at the peak, if lock-down continues.

The continuation of Lock-down will help to flatten the curve further. Please note that, even though the number of infection looks high, only small portion of population is likely to be serious. So government should plan lock-down in such a way that the fraction of population likely to be serious during the peak period is within the countries healthcare capacity to handle such condition.

Please note that this is mathematical simulation and prediction based on model. It is aimed to give guidance for the policy makers for planning purpose only. General public should not be afraid of these hypothetical scenarios, as government would hopefully take better measures to keep the condition under control (like they are doing at the current situation).

Let’s all support the Lock-down. I can also make prediction on how worse it can be if lock-down will be removed. But, I don’t want to make that public already. 

Please provide feedback, suggestions and relevant comments. If anybody wants to get code to do such modeling and simulation, contact me.