Need to Bring Down 'R' Value to Control Corona Spread, say Experts: What is 'R' Value?

As the spread of the novel coronavirus is becoming a huge threat to humanity in many countries, social distancing is seen as the only solution. In the absence of a vaccine, it is becoming very important for people to protect themselves from the infection, by wearing Personal Protective Equipment and refraining from coming in close contact with people.

Under these circumstances, decreasing the R value has been seen as the top priority by the doctors.

The R value is basically the value of reproduction. Reproduction here refers to the ability of the virus to multiply and spread to different people. R value here is taken as the average number of people among whom the virus can spread from one person.

For instance, some contagious diseases have a R value of 15, meaning, one person with the infection can spread it to 15 others.

It has been discovered that the R value for COVID-19 is 3. However, this number is varying in different countries. Dr Philip Lee, a consultant physician in acute medicine and medicine for the elderly, wrote about it at length on Twitter.

"For the uninitiated, R0 is the basic reproduction number for a disease. This is basically how many people one infected person will go on, on average, to infect. For instance, one child with measles can infect up to 18. Hence the importance of vaccination. As long as R is above one, this means the number of infected persons will grow,” he wrote.

He also cited an example to enforce the importance of reducing the R value, "Eric who has COVID-19 might pass it onto Margaret from accounts, Sanjay who touched a handrail he touched, Susan his wife, and Bob who met him for a drink. R here is 4. BUT if Margaret worked from home, Sanjay cycled or used hand sanitizer coming off the bus, and Bob told Eric to p*** off, then the R falls to 1. And if Susan sleeps in a different room, washes her hands all the time and stops Eric from germing up the city, R is even lower. Hence the importance of ongoing social distancing measures. The lower R is, the faster we will reduce the threat of this spreading again.”

The London School of Hygiene and Tropical Medicine’s head told BBC that the restrictions on lockdown can only be compromised if the R value is below 1. Hence, it is only when people follow the norms of social distancing, and take personal care, will the value of R fall below 1.

However, this scenario will be different once a vaccine is proven to be effective. Once people are vaccinated for COVID-19, then the value of R will automatically fall below one as people will then be protected against the virus.