Written Evidence Submitted by

Professor Xihong Lin, Professor of Biostatistics at Harvard T.H. Chan School of Public Health




1.       What the UK can learn from the social distancing measures employed in China and other countries.




We analyzed data from 32,000 lab-confirmed COVID-19 patients in Wuhan until March 9 to study public health (non-pharmaceutical) intervention effects and the epidemiological characteristics of these patients. The paper was published in Journal of the American Medical Association (JAMA) on April 10.


General principles and key take home messages


  1. The general principle for controlling an epidemic is simple: To stop an outbreak, need to reduce the number of new infections. How? Detect the source of infection, i.e., infected patients. Isolate infected patients to block the transmission chain so they won’t infect others, and have infected patients be treated early to reduce the risk of deaths.
  2. The effective reproducible number R value is the average number of people infected by a case. To fully control the epidemic, need to bring the R value way below 1 and make it close to 0 as much as possible.
  3. To achieve this, multi-faceted measures are needed, which include six pillars: mask wearing, social distancing, widespread testing, contact tracing, isolating infected patients and quarantining symptomatic subjects and close contacts, and treating infected patients.
  4. Both social distancing AND centralized isolation and quarantine are needed to fully control the outbreak. Social distancing, testing, and contact tracing greatly help but are not enough. Centralized isolation and quarantine helped  crunch the curve in a timely fashion, protect loved ones, and save lives of loved ones, and stop the outbreak.
  5. Analyze real data and facilitate decision making based on real data analysis results, in addition to simulated data.
  6. Every country is different, detailed implementation of the general principles needs to adapt to each country’s own situation and culture, by learning from other cities and countries, such as Wuhan, South Korea, Singapore as well as Italy and Germany. It should not be copy and paste.  It is not just about modelling, but also about effective implementation of the six pillars: public health implementation, health care implementation and society implementation.
  7. Effective public education and communication is critically important, both to share gained scientific knowledge and inform the public to make good decisions for themselves, loved ones and communities.
  8. Wuhan experience discussed in our JAMA paper and other country’s experience let us not to start 0. We can control the outbreak in a timely fashion if we as a community work together and do it right. We don’t need to wait for one year.


Social distancing:


Smart/Centralized isolation and quarantine:


Testing priorities:


2.       Strategies taken by other countries (e.g. Austria) to lifting coronavirus restrictions and how they are informed by science: How lifting restrictions may affect the spread of COVID19. What should an ‘exit strategy’ contain (for example economic considerations)? What can the UK learn from other countries?


Guidin Principle:





(April 2020)