PrEP Drug 'Could Prevent 1 in 4 HIV Infections'

Peter Russell

October 23, 2017

A drug that can reduce the risk of HIV infection among men who have sex with men would save the NHS money in the long-term, a study has found.

A research team led by University College London concludes that providing pre-exposure prophylaxis (PrEP) to those at high risk of infection could prevent up to 1 in 4 cases of HIV

What Is PrEP?

The PrEP pill is a combination of 2 anti-retroviral drugs – emtricitabine and tenofovir – produced in a tablet form under the brand name Truvada.

The medication is taken either daily or before and after sexual activity so that it can block HIV if it gets into the body.

Both methods have been effective in trials.

Despite the high cost of the medication, PrEP is available on the NHS in Scotland.

In England, the NHS initially refused to pay for PrEP, arguing that responsibility for HIV prevention lay with local authorities. In November 2016, the Court of Appeal upheld a ruling that NHS England has the legal power to fund PrEP. It has since agreed to a trial involving around 10,000 people in some clinics.

A trial of PrEP has also been sanctioned in Wales.


The latest study, published in The Lancet Infectious Diseases journal, is the first to assess the cost-effectiveness of a national roll-out of PrEP.

The researchers evaluated the cost effectiveness of PrEP by comparing HIV infection rates under 2 different scenarios: one in which PrEP was not available and the other assuming that it was available with an average of 5 pills taken each week.

The study assumed that PrEP would be offered to HIV-free men who had had anal sex without a condom in the previous 3 months. It also assumed they would have had a negative HIV test in the preceding year.

In 2016, the year in which the researchers assumed that a PrEP rollout would have begun, the number of men who had sex with men in the UK was estimated to be 725,200, of whom 585 000 were aged 15 to 64 years old.

They estimated that between 8,400 and 12,200 men aged between 15 and 64 would be considered at high risk of HIV infection and eligible to use PrEP in the UK in 2016.

They predict that in the first year of a national roll-out, 4,000 men would begin taking PrEP, rising to 16,600 men after 5 years, and 38,900 men would be taking it by the 15th year. 

They estimate that the men would take the drug for an average of 4-and-a-half years.

The study anticipates that, despite initial costs, treatment with PrEP would become cost-effective 40 years or more after the programme began. However, cost-effectiveness could come earlier as patents expire and generic versions of the medication reach the market.

For instance, an 80% drop in the cost of the drugs would make a PrEP treatment programme cost-effective in 20 years, say the researchers.

Preventing Around a Quarter of Infections

Over 80 years, they estimate that 1 in 4 HIV infections could be prevented by PrEP, equivalent to 44,300 fewer HIV infections compared with a scenario in which PrEP was not available.

They estimate that this would save the NHS up to £1 billion over this time frame because fewer men would need lifelong HIV treatment.

In a linked comment article in the same journal, Paul Revill and Ellen Dwyer, from the Centre for Health Economics at the University of York, write: "These findings … call for NHS policy makers to negotiate with manufacturers to get favourable deals on prices and to be far sighted: invest now and reap long-term gains."

They add: "With a combination of frequent HIV testing, immediate treatment, and PrEP availability, there is now the prospect of bending the curve of new HIV infections downwards in a way that did not seem feasible just a few years ago.

"Will this progress occur or will these efforts be hampered by continued NHS reorganisation and funding quarrels between government departments? Only time will tell."

Dr Michael Brady, medical director at the Terrence Higgins Trust, comments in an emailed statement: "One of the key arguments against PrEP has been that it will cost the NHS too much money. This study firmly puts that claim to bed by demonstrating that, when appropriately targeted at those at risk of HIV, it is not only highly cost effective but, as the price of HIV drugs falls, will actually save the NHS money in the long run.

"Each HIV infection prevented saves the NHS £360,000 of a lifetime of treatment and care."


Cost-effectiveness of pre-exposure prophylaxis for HIV prevention in men who have sex with men in the UK: a modelling study and health economic evaluation, Cambiano V, et al, The Lancet Infectious Diseases

Pre-exposure prophylaxis is cost-effective for HIV in the UK, Revill P, Dwyer E, The Lancet Infectious Diseases

Terrence Higgins Trust


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