Prior to taking up senior positions with the pharmaceutical company
GlaxoSmithKline (GSK) and later in the UK Government, Vallance spent several years in medical research.
St George's Hospital From 1986 to 1995 Vallance taught at
St George's Hospital Medical School, where his research concentrated on
vascular biology and
endothelial cell physiology. In 1987, with
Joe Collier, he set out to investigate whether human blood vessels demonstrated endothelium-dependent relaxation, a term coined in 1980 by
Robert F. Furchgott and John V. Zawadzki after discovering that a
large blood vessel would not relax when its
single-layered innermost lining was removed. Furchgott and Zawadzki subsequently showed that the occurrence was mediated by what they called
endothelium-derived relaxing factor, later found to be nitric oxide, and it was shortly shown to occur in a variety of animals. Using veins from the back of a human hand, Vallance and Collier reproduced Furchgott and Zawadzki's findings. Subsequently, their team showed that the human
arterial vasculature is actively dilated by a continuous release of nitric oxide. In 1991, Vallance and
Salvador Moncada published a paper on the role of nitric oxide in
cirrhosis, proposing an association between the changes in blood flow in cirrhosis and the vasoactive properties of nitric oxide. The following year they reported that the plasma concentrations of
asymmetric dimethylarginine (ADMA) were elevated in people who were
uraemic.
University College Hospital From 1995 to 2002 he was a professor at
UCL Medical School, then professor of Medicine from 2002 to 2006, and head of medicine. He was also
registrar of the
Academy of Medical Sciences.
GlaxoSmithKline In 2006, in his mid-40s, Vallance joined GSK as head of
drug discovery. Four years later he became head of medicines discovery and development, and in 2012 he was appointed head of research and development at GSK. Under his leadership, new medicines for
cancer,
asthma,
autoimmune diseases and
HIV infection were discovered and approved for use worldwide. He championed
open innovation and novel industry-academic partnerships globally,
UK Government behind him In March 2018, Vallance left GSK, and on 4 April 2018 he began his five-year tenure as
Chief Scientific Adviser to the UK Government, replacing the interim officeholder
Chris Whitty. In this role he led the
Government Office for Science, advising the Prime Minister and the Cabinet. In 2018, he was one of nine scientific advisers who, in a paper in
Nature, called for "inclusive, rigorous, transparent, and accessible information for policy makers" and supported the Evidence-Based Research Network, established in 2016, to "lobby for all proposals for new research to be supported by references to systematic reviews of relevant existing research".
COVID-19 pandemic In March 2020, as the Government's Chief Scientific Adviser, Vallance appeared alongside Prime Minister
Boris Johnson and the
Chief Medical Officer for the UK,
Chris Whitty, in televised briefings on the
COVID-19 pandemic. During some March 2020 TV interviews, he made comments interpreted by some as advocating for a "
herd immunity" approach. However, in his second written statement to the
UK COVID-19 Inquiry, he stated that he misspoke while trying to explain a "technically difficult concept", that interviews given that same day demonstrate that he was not advocating for such a policy, and the later published transcripts of
SAGE demonstrate that no such policy was being considered or advocated by government scientific advisors including Vallance. Vallance stated in the same statement that he "regrets" his use of the term "herd immunity" in those instances. His "
herd immunity" approach was criticised by a group of 541 scientists from UK and international universities and research institutions, who expressed the view that this approach would put the
NHS under additional stress and "risk many more lives than necessary". The 541 signatories work in epidemiology, computational modelling, applied mathematics, mathematical biology, probability theory, complex systems, computational biology, molecular medicine, amongst others. In September, it emerged that Vallance owned a deferred bonus of 43,111 shares worth £600,000 in GlaxoSmithKline, a company which was working on developing a COVID vaccine. This led to claims of a potential conflict of interest, as Vallance could be seen to have a financial interest in pushing for a vaccine-based response to the pandemic whether or not this was objectively the best approach. Then Health Secretary
Matt Hancock denied that this was the case, with a government spokesperson stating that, "Upon his appointment, appropriate steps were taken to manage the Government Chief Scientific Adviser's interests in line with advice provided at the time. The GCSA has no input into contractual and commercial decisions on vaccine procurement which are taken by Ministers following a robust cross-Government approvals regime". After a televised briefing alongside Johnson and Whitty on 31 October, where a second "lockdown" was introduced for England, Vallance was criticised for showing two slides – projecting hospital admissions and deaths – which were later reissued with worst-case figures revised downward. Five days later, a statement from the
Office for Statistics Regulation called for greater transparency in published data relating to the pandemic, including publication of data sources and modelling assumptions; the statement did not refer to any specific presentation but was linked by reporters to the 31 October briefing.
Minister of State for Science On 5 July 2024, Vallance was appointed Minister of State for Science in the Department for Science, Innovation and Technology by Prime Minister
Keir Starmer following the Labour Party's victory at the
2024 general election. He continued as
Minister of State for Science, Innovation, Research and Nuclear following a reorganisation in September 2025. On 17 July 2024 he was created a
life peer, taking the
title of
Baron Vallance of Balham, of Balham in the London Borough of Wandsworth. He sits on the Labour benches in the
House of Lords. In November 2024, Vallance gave the opening speech at the
Royal Institute of Navigation annual seminar. In November 2025, Vallance introduced a plan to phase out
animal testing through increased use of
artificial intelligence and
3D bioprinting.
Other work In February 2024, Vallance joined the
Tony Blair Institute for Global Change's team of strategic counsellors, advising the organisation on its global policy work.
Selected publications Vallance's publications include: •
Hyperdynamic circulation in cirrhosis: a role for nitric oxide? •
Physiological importance of nitric oxide •
Exploring vascular nitric oxide in health and disease •
Nitric oxide in the human cardiovascular system •
Sildenafil: desired and undesired effects •
Four principles to make evidence synthesis more useful for policy ==Honours and awards==