The reproduction number 𝑅 is a key indicator used to monitor the dynamics of Covid-19 and to assess the effects of infection control strategies that frequently have high social and economic costs.

Scientists say there is no evidence that the BA.5 version of the Omicron coronavirus variant is more transmissible than measles, or that it has a basic reproduction number, or "R-naught" (R0), of 18.6 ...

The "reproductive rate," or Rt, is a key metric in measuring how fast a virus is growing, and San Francisco's Director of Health Dr. Grant Colfax said it's the indictor that he's closely watching ...

We published an article earlier this month that contained incorrect estimates for the basic reproduction number (R0) for COVID subvariants BA.4/BA.5 and BA.2. We have now corrected the error, but I ...