In epidemiology, the basic reproduction number, or basic reproductive number, denoted , of an infection is the expected number of cases directly generated by one case in a population where all individuals are susceptible to infection. The definition assumes that no other individuals are infected or immunized. Some definitions, such as that of the Australian Department of Health, add the absence of "any deliberate intervention in disease transmission". The basic reproduction number is not necessarily the same as the effective reproduction number , which is the number of cases generated in the current state of a population, which does not have to be the uninfected state. is a dimensionless number and not a time rate, which would have units of time−1, or units of time like doubling time.
Sir Roy Malcolm Anderson is a leading international authority on the epidemiology and control of infectious diseases. He is the author, with Robert May, of the most highly cited book in this field, entitled Infectious Diseases of Humans: Dynamics and Control. His early work was on the population ecology of infectious agents before focusing on the epidemiology and control of human infections. His published research includes studies of the major viral, bacterial and parasitic infections of humans, wildlife and livestock. This has included major studies on HIV, SARS, foot and mouth disease, bovine tuberculosis, bovine spongiform encephalopathy (BSE), influenza A, antibiotic resistant bacteria, the neglected tropical diseases and most recently COVID-19. Anderson is the author of over 650 peer-reviewed scientific articles with an h-index of 125.
The American Institute for Economic Research (AIER) is a conservative libertarian think tank known for spreading climate and health misinformation, located in Great Barrington, Massachusetts. It was founded in 1933 by Edward C. Harwood, an economist and investment advisor. It is a 501(c)(3) nonprofit.
Sir Adrian Vivian Sinton Hill, is an Irish vaccinologist, Director of the Jenner Institute and Lakshmi Mittal and Family Professor of Vaccinology at the University of Oxford, an honorary Consultant Physician in Infectious Diseases, and Fellow of Magdalen College, Oxford. Hill is a leader in the field of malaria vaccine development and was a co-leader of the research team which produced the Oxford–AstraZeneca COVID-19 vaccine, along with Professor Sarah Gilbert of the Jenner Institute and Professor Andrew Pollard of the Oxford Vaccine Group.
Sir Christopher John MacRae Whitty is a British epidemiologist, serving as Chief Medical Officer for England and Chief Medical Adviser to the UK Government since 2019.
Devi Lalita Sridhar FRSE is an American public health researcher, who is both professor and chair of global public health at the University of Edinburgh, Scotland. Her research considers the effectiveness of public health interventions and how to improve developmental assistance for health. Sridhar directs the University of Edinburgh's Global Health Governance Programme which she established in 2014.
The COVID-19 pandemic, also known as the coronavirus pandemic, is a global pandemic of coronavirus disease 2019 (COVID-19) caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). The novel virus was first identified in an outbreak in Wuhan, the capital of Hubei, China, in December 2019, before it spread to other areas of Asia, and then worldwide in early 2020. The World Health Organization (WHO) declared the outbreak a public health emergency of international concern (PHEIC) on 30 January 2020, and assessed the outbreak had become a pandemic on 11 March 2020. The WHO ended the PHEIC on 5 May 2023. As of 6 April 2024, the pandemic has caused 7,042,222 confirmed deaths, making it the fifth deadliest pandemic or epidemic in history.
Coronavirus disease 2019 (COVID-19) is a contagious disease caused by the coronavirus SARS-CoV-2. The first known case was identified in Wuhan, China, in December 2019. The disease quickly spread worldwide, resulting in the ongoing COVID-19 pandemic.
Neil Morris Ferguson is a British epidemiologist and professor of mathematical biology, who specialises in the patterns of spread of infectious disease in humans and animals. He is the director of the Jameel Institute, and of the MRC Centre for Global Infectious Disease Analysis, and head of the Department of Infectious Disease Epidemiology in the School of Public Health and Vice-Dean for Academic Development in the Faculty of Medicine, all at Imperial College London.
Dame Sarah Catherine Gilbert FRS is an English vaccinologist who is a Professor of Vaccinology at the University of Oxford and co-founder of Vaccitech. She specialises in the development of vaccines against influenza and emerging viral pathogens. She led the development and testing of the universal flu vaccine, which underwent clinical trials in 2011.
Azra Catherine Hilary Ghani is a British epidemiologist who is a professor of Infectious Disease Epidemiology at Imperial College London. Her research considers the mathematical modelling of infectious diseases, including malaria, bovine spongiform encephalopathy and coronavirus. She has worked with the World Health Organization on their technical strategy for malaria. She is associate director of the MRC Centre for Global Infectious Disease Analysis.
In response to the COVID-19 pandemic in the United Kingdom, the UK Government introduced various public health and economic measures to mitigate its impact. Devolution meant that the four nations' administrative responses to the pandemic differed; the Scottish Government, the Welsh Government, and the Northern Ireland Executive produced different policies to those that apply in England. Numerous laws were enacted or introduced throughout the crisis.
Caroline O'Flaherty Buckee is an epidemiologist. She is a Professor of Epidemiology at the Harvard T.H. Chan School of Public Health. Buckee is known for her work in digital epidemiology, where mathematical models track mobile and satellite data to understand the transmission of infectious diseases through populations in an effort to understand the spatial dynamics of disease transmission. Her work examines the implications of conducting surveillance and implementing control programs as a way to understand and predict what will happen when dealing with outbreaks of infectious diseases like malaria and COVID-19.
Isabella Eckerle is a German virologist who is the co-Head of the Centre for Emerging Viral Diseases at the Geneva University Hospitals and the University of Geneva. Her research considers infectious diseases and the development of cell lines that allow a better understanding of their epidemiology. During the COVID-19 pandemic, Eckerle studied the difference in response of adults and children to coronavirus disease.
Scott William Atlas is an American radiologist, political commentator, and health care policy advisor. He is the Robert Wesson Senior Fellow in health care policy at the Hoover Institution, a conservative think tank located at Stanford University. During the United States presidential campaigns of 2008, 2012, and 2016, Atlas was a Senior Advisor for Health Care to several presidential candidates. From 1998 to 2012 he was a professor and chief of neuroradiology at Stanford University Medical Center.
The Independent Scientific Advisory Group for Emergencies, better known as Independent SAGE, is a group of scientists, unaffiliated to government, that publishes advice aimed toward the UK government regarding the COVID-19 pandemic. Its name is based on SAGE, the name of the government's official Scientific Advisory Group for Emergencies.
The Great Barrington Declaration was an open letter published in October 2020 in response to the COVID-19 pandemic and lockdowns. It claimed harmful COVID-19 lockdowns could be avoided via the fringe notion of "focused protection", by which those most at risk of dying from an infection could purportedly be kept safe while society otherwise took no steps to prevent infection. The envisaged result was herd immunity within three months, as SARS-CoV-2 swept through the population.
Jayanta "Jay" Bhattacharya is an Indian American professor of medicine, economics, and health research policy at Stanford University. He is the director of Stanford's Center for Demography and Economics of Health and Aging. His research focuses on the economics of health care.
Martin Kulldorff is a Swedish biostatistician. He was a professor of medicine at Harvard Medical School from 2003 until his dismissal in 2024. He is a member of the US Food and Drug Administration's Drug Safety and Risk Management Advisory Committee and a former member of the Vaccine Safety Subgroup of the Advisory Committee on Immunization Practices at the US Centers for Disease Control and Prevention.
Lyda Elena Osorio Amaya is a Colombian physician, epidemiologist and infectious disease specialist. She is an associate professor at the Universidad del Valle, and a researcher at the Centro Internacional de Entrenamiento e Investigaciones Médicas (CIDEIM) in Cali, Valle del Cauca. Osorio's research has focused mainly on vector-borne diseases like malaria, leishmaniasis, Zika and dengue fever. She has also played a role in Colombia's response against COVID-19.
