Tegnell was born in Uppsala.
He became a licensed physician at Lund University in 1985, subsequently interning at the county hospital in Östersund, and later specialised in infectious disease at Linköping University Hospital.
In that capacity, in 1990 he treated the first patient in Sweden with a viral hemorrhagic fever, believed to be a case to be either the Ebola or the Marburg virus disease.

From 1990 to 1993 he worked for the WHO in Laos to create vaccination programs.
In an interview with Expressen, he describes his on-site work for the WHO with a Swedish expert team during the 1995 Ebola outbreak in Kikwit, Zaire as a formative experience.

From 2002 to 2003 he also worked as a national expert for the European Commission to prepare at the EU level for public health threats such as anthrax, smallpox and other infectious diseases.

Tegnell obtained a research-based senior Medical Doctorate from Linköping University in 2003 and a MSc in Epidemiology from the London School of Hygiene and Tropical Medicine in 2004.
He worked at the Swedish Institute for Communicable Disease Control (Smittskyddsinstitutet) 2004–2005 and the National Board of Health and Welfare from 2005.
As head of the Infectious Disease Control department at the agency, he had a key role in the Swedish large-scale vaccination program in preparation for the H1N1 swine flu pandemic in 2009.
He is known for being responsible in the decision to use clinically unproven vaccine which lead to 400 people currently living with Narcolepsy .
From 2010 to 2012 he served as head of the Department for Knowledge-Based Policy.
He was department head at the Institute for Communicable Disease Control 2012–2013.
Since 2013 he is the State Epidemiologist of Sweden, first at the Institute for Communicable Disease Control, which in 2014 became part of the Public Health Agency of Sweden.

Anders Tegnell was elected member of the Royal Swedish Academy of War Sciences in 2005.
His inaugural lecture was on the effect of pandemics on society.
Tegnell was born in Uppsala. He became a licensed physician at Lund University in 1985, subsequently interning at the county hospital in Östersund, and later specialised in infectious disease at Linköping University Hospital. In that capacity, in 1990 he treated the first patient in Sweden with a viral hemorrhagic fever, believed to be a case to be either the Ebola or the Marburg virus disease.
From 1990 to 1993 he worked for the WHO in Laos to create vaccination programs. In an interview with Expressen, he describes his on-site work for the WHO with a Swedish expert team during the 1995 Ebola outbreak in Kikwit, Zaire as a formative experience. 
From 2002 to 2003 he also worked as a national expert for the European Commission to prepare at the EU level for public health threats such as anthrax, smallpox and other infectious diseases.
Tegnell obtained a research-based senior Medical Doctorate from Linköping University in 2003 and a MSc in Epidemiology from the London School of Hygiene and Tropical Medicine in 2004. He worked at the Swedish Institute for Communicable Disease Control (Smittskyddsinstitutet) 2004–2005 and the National Board of Health and Welfare from 2005. As head of the Infectious Disease Control department at the agency, he had a key role in the Swedish large-scale vaccination program in preparation for the H1N1 swine flu pandemic in 2009. He is known for being responsible in the decision to use clinically unproven vaccine which lead to 400 people currently living with Narcolepsy . From 2010 to 2012 he served as head of the Department for Knowledge-Based Policy. He was department head at the Institute for Communicable Disease Control 2012–2013. Since 2013 he is the State Epidemiologist of Sweden, first at the Institute for Communicable Disease Control, which in 2014 became part of the Public Health Agency of Sweden.
Anders Tegnell was elected member of the Royal Swedish Academy of War Sciences in 2005. His inaugural lecture was on the effect of pandemics on society.
Anders Tegnell