In the 1980s, Anne Johnson was at the forefront of research into the spread of HIV, and she sees some worrying parallels between then and now in terms of expectations.

“As with the COVID-19 epidemic, most people were interested in developing a vaccine or a cure, or wondering how to treat people,” she recalls. “I have cuttings from 1986 that say a vaccine will be available in 18 months. Nearly 35 years on, and there is still no vaccine. Yes, there have been incredible scientific advances, but the major impact of antiretrovirals at scale in reducing transmission dates back about 15 years. And we still rely on behaviour change and condoms.”

Johnson’s specialism is the role that behaviour plays in spreading disease within populations. With HIV, her ground-breaking studies of sexual behaviour caused offence in government – “they were banned by Margaret Thatcher from receiving public funding” she recalls - but proved crucial to public understanding of how the virus spread. With that knowledge, collective behaviour did change, dramatically.

The lesson, thinks Johnson, is that preventative public health measures should never be marginal to dealing with infectious diseases, because “by and large, the single magic bullet doesn’t exist.” COVID-19, has proved much more transmissible than we first thought, while immunity from a vaccine is far from guaranteed. We may be living with the virus for some time to come, thinks Johnson, which demands a fresh focus on prevention and public health.

We will need a proper “alliance” between government, a sense of “collective responsibility” - and a return to some fundamental 19th century methods.

“And they resulted from improved housing, water and sanitation, improved employment and nutrition, the end of child labour, and improved air quality. Vaccines have been hugely important. But if you take something like TB, there's good evidence that TB rates came down massively before we had antibiotics, antimicrobials or a vaccine.”

Every student of epidemiology knows the story of the anaesthetist and epidemiologist John Snow, who in 1854 traced the source of a cholera outbreak in Soho back to a communal water-pump, and had the local authority remove the handle. Snow’s discovery was based upon detailed research, plotting cholera cases in the vicinity and showing the correlation between consumption of water from the pump and cholera infection.

“Data is power,” says Johnson. “It was then, it is now. Snow didn’t know anything about the biology of cholera. He just figured out that if I stop people drinking the water, we may stop the source of the epidemic. I think we have lost some of the focus on basic empirical approaches to understanding infectious disease in terms of time, place and person (risk factors) in order to intervene to improve public health. Empirical surveillance data is key and nowadays that depends on widespread availability of testing for infections. We’ve forgotten 19th century prevention, just at time when our interventions are in fact 19th century – you, know, just staying out of contact with each other and improving basic hygiene.”

Effective public health measures require collective action towards clear goals, and she is concerned that COVID-19 shows how opaque thinking and messaging has become in this regard. We are still not clear about whether we are aiming to eliminate or just suppress COVID-19 – “the goal of the lock-down was substantially driven by the need to protect the NHS” - although other countries proved that with a concerted public health approach, it was possible to get close to stamping out the virus. Similarly, we have vacillated about mandating the wearing of masks, becoming side-tracked by straw-man arguments about personal liberty or the effectiveness of different types of mask.

“For a public health intervention at scale you don't need to have a perfect mask, anymore than a condom is perfect protection from STDs - I'll make the analogy! What you want is a cultural change, which may need to be mandated, so that everybody uses a mask for example. It won't be fool-proof, but we will reduce transmission. That's a public health approach rather than an individual approach. And it is really difficult to get across to people.”

What does she mean by there being a need for a proper “alliance” with the public?

“I’m really concerned about the long-term impact of this pandemic because it's unequally distributed. We're going to see big effects on employment and education – on all the things which drive health. So we will need a much stronger public health effort, driven by the clear message that all of us stand to benefit. It's about the collective. If we all worked to change some behavioural and cultural norms and make key environments safer (eg transport, workplace, hospitals and care homes), we might be able to get back to a way of life that we all want.”

She understands the importance of people going back to work but thinks that if “the endgame is to open up the economy, but keep the virus suppressed,” the government needs to have that alliance - a “pact with the public” – that makes them partners in the public health effort and recognises the specific needs of high-risk and local communities.

Johnson thinks that so far, the public have been noticeably absent from the debate: “We have had a lot of experts, a lot of voices from government, but actually we haven't really heard the voice of the public and what they feel.”

In fact, the disproportionate impact of COVID-19 on deprived and minority ethnic communities has highlighted this gulf in representation and understanding and showed that we often have little idea who ‘the public’ are, and how we should speak with them.

“Are we doing enough to communicate with particular BAME communities, for example, in London who have been very badly hit?” asks Johnson. “Where's the engagement, in the language, in the culture, with the religious leaders? All the stuff that we would naturally talk about in an Ebola epidemic, now seems to be less prominent in the discourse.”

She points to the way that low-paid workers can’t avoid close contact because they have public-facing jobs or live in crowded housing or “don't hear the government messages because they don't watch the news briefings at 4pm.” How, with this lack of opportunity and information, can people grasp the nature of the epidemic or know what they could do to reduce it, or to protect themselves?

“We have to get a much stronger engagement with the public and local communities and about what we can individually and collectively do,” she says, “While somehow also getting on with our lives.”

Johnson says - laughing - that she’s been called a “drain sniffer” by research colleagues, which is revealing of the less-than-glamorous view of public health, in a world where personalised genetic medicine is the next, exciting thing.

“How do you make public health an exciting subject?” she ponders. “If you get things right, everybody says, ‘well you said we were going to have a gazillion deaths and we didn't, so you were scaremongering’. Nothing happens. Which is rather dull for some people. They don’t get excited about the idea that we need to change behaviours and the environments that enable behaviour change and protect people.”

She thinks that the past decade has seen “a tremendous big disinvestment in public health,” the separation of prevention and public health from research and treatment, and the concentration of resources on other areas of medical research.

But she is hopeful “the pendulum is swinging back”, with funders from different sectors coming together to support initiatives that address socio-economic inequalities defining public health. She points to her experience of the UK Prevention Research Partnership, “which is led by the Medical Research Council but involves 14 funders.” Among the Programmes it supports is ActEarly, looking at early life chances and working between Tower Hamlets and Bradford.

What more does Johnson think we could be doing? “I think that’s one of the big criticisms of epidemiologists,” she says. “People working in public health in local authorities would say, ‘don't tell me anymore what the problem is.’ Show me what to do about it - and I don't want to wait five years for the answer.”

The answer, she thinks, lies more in evidence-based public health interventions, focussed particularly on reducing health inequalities, working in alliance with local authorities, drawing together economists, town planners, transport experts, physicists, lawyers and engineers. Research, she says, will be “messy and multi-disciplinary.”

“We need to be doing more stuff at the local level,” she says. “But I do feel encouraged. There's obviously the push from Nesta,” the idea of a new centre of expertise that could lead this work. The Academy of Medical Sciences report on ‘Improving the Health of the Public by 2040’ raised many of these issues. The Health Foundation is committed to this; UKRI has a big initiative to fund food systems research which is a huge issue of obesity - an understanding that's not just about the biology but about the agriculture and food industry about processed foods, and so on.”

In conversation, Johnson frequently refers to the importance of collective responsibility - of persuading people to work together. In public health, individual needs are addressed through collective changes, socio-economic, environmental, legal and behavioural. She is similarly strong on the value of international partnerships and thinks “it’s concerning how relatively little collaboration there was” between the UK and other countries.

“We can sometimes have this British exceptionalism, which has been commented on,” she reflects. “Sometimes we might think we know better. We've got great scientists but we all need to learn from one another. But we have fared very badly. There is no doubt on any metrics we've had a very intense epidemic. With Ebola, people got together an international response, and the problem was handled more effectively. Now we’ve all got our own problems, we need to avoid scurrying around in a nationalistic way.”

“I would hope that COVID-19 makes us wake up and realise that solving these problems is not a matter of pitching one against the other. It's the sum of a bunch of different things brought together. That’s the message of public health; the sum of many small effects can make big differences.”

Dame Anne Johnson is a behavioural epidemiologist and Professor of Infectious Disease Epidemiology at UCL. She describes her work as “studying how infections spread in populations and the role that behaviour plays.” She trained in clinical medicine and since the 1980s has worked in public health. Anne is also Chair of the UK Strategic Co-ordinating Body for Health of the Public Research (SCHOPR), formed in response to a recommendation in The Academy of Medical Sciences (AMS) report, Health of the Public 2040, to help with “substantially, continually and sustainably improving health and health equity by identifying research needs and coordinating research activities”. SCHOPR produced a set of recommendations for all devolved nations, setting out clear public health research principles and goals to drive improvements in the UK’s public health research.