01Role and principlesWho benefits and the main preventive aims.
Safer-sex counselling works when it is specific enough to be usable. Ask what the patient wants to prevent or achieve, which anatomical sites and practices are involved, how often barriers are feasible, whether pregnancy is possible, and what has made previous plans difficult. Avoid presenting abstinence or one product as the only responsible choice. Agree small interventions that fit the person’s relationships, housing, privacy, dexterity, substance use and reproductive intentions.
External condoms reduce exposure to semen, vaginal or rectal fluid and mucosal contact when used before any genital contact and throughout sex. Use compatible lubricant to reduce breakage and avoid using two condoms together. Internal condoms are another option for vaginal sex and may help for anal sex, although evidence and product instructions differ. Barriers do not fully cover skin, so herpes, HPV, syphilis lesions and mpox can still transmit from uncovered areas.
Testing is prevention only when sites and timing are correct and results lead to action. Offer genital, rectal, pharyngeal, lesion and blood testing according to exposure and symptoms. Explain diagnostic windows and retesting after an early negative. Positive results need treatment, organism-specific abstinence advice and partner notification. A routine screen cannot replace urgent assessment for pain, fever, pregnancy complications or neurological disease.
HIV PrEP provides pre-exposure protection when the regimen is clinically appropriate and taken correctly; PEP is an emergency response after a qualifying exposure and should begin as soon as possible, no later than the current programme limit. Neither prevents other STIs or pregnancy. People using PrEP still need renal, infection and adherence monitoring according to the current regimen, and symptoms of acute HIV require expert assessment before initiation or continuation.
Hepatitis B vaccination is offered to people at increased exposure risk, including GBMSM, people who change sexual partners frequently and sex workers under the February 2026 Green Book. Contacts of acute or newly diagnosed chronic hepatitis B need prompt specialist assessment; vaccine and sometimes hepatitis B immunoglobulin depend on source status and time since contact. Vaccination history, serology and immune state guide the course and follow-up.
HPV vaccination follows programme age, risk and immune status. The routine adolescent and catch-up programmes coexist with offers through specialist sexual-health or HIV services, including GBMSM up to and including age 45 under the UKHSA programme. Most eligible people need fewer doses than immunosuppressed people or those living with HIV; verify the current schedule rather than assuming that every adult needs three doses.
The UK targeted 4CMenB gonorrhoea vaccination programme continues through sexual-health services, primarily for GBMSM at higher risk. Use against gonorrhoea is off-label. Individual protection is uncertain and may be relatively low: the July 2026 GoGoVax RCT found no evidence of protection in its studied high-risk population, although population-level benefit remains possible. Continue condoms and regular STI testing, and check current eligibility and access for the patient’s nation and local service. Mpox offers are likewise risk- and programme-specific.
Contraception and consent complete the plan. Condoms can add STI protection to another contraceptive method, and emergency contraception may be needed after failure. Ask whether sex is wanted and whether a partner controls condoms, medicines, money or clinic access. Reproductive coercion and violence require a safety plan, sometimes including a discreet method or provider-led partner notification.
Key points
- Agree the patient’s priorities and describe practices, sites, timing, barriers, partners, pregnancy potential, consent and previous tests before choosing interventions.
- Condoms reduce many STI and pregnancy risks when used correctly throughout exposure, but protection varies by infection, anatomical site and uncovered skin.
- PrEP prevents HIV when taken correctly; it does not prevent pregnancy, syphilis, gonorrhoea, chlamydia, hepatitis C or infections spread from uncovered skin. The UK 4CMenB gonorrhoea programme continues, but use against gonorrhoea is off-label and individual protection is uncertain and likely low; the 2026 GoGoVax RCT found no evidence of protection in its high-risk study population, so continue condoms and testing.
- Use regular site-specific testing, vaccination, contraception, partner care and substance or safety support as complementary layers rather than a single universal package.
- Check hepatitis B, HPV and mpox vaccination against current risk, age, immune status and previous doses; check 4CMenB eligibility and access through the responsible UK-nation and local pathway.
- Vaccination reduces future risk but does not treat established infection or replace symptom assessment, testing, condoms, PEP or PrEP.
- Close with a realistic goal, supplies or referral, a confidential follow-up route and explicit action after condom failure, symptoms or an unwanted exposure.
02Assessment and patient selectionRisk features, eligibility and important cautions.
HIV, pregnancy and hepatitis B exposures can require prophylaxis or emergency contraception before routine results return.
Fit, lubricant, timing, site, breakage and whether uncovered skin contacts a lesion determine what a condom can and cannot prevent.
Ongoing HIV exposure risk, ability to use the regimen and renal or infection assessment guide PrEP discussion; PEP addresses a past exposure.
Frequent partner change, GBMSM networks, sex work, injecting exposure or contact with hepatitis B can trigger targeted vaccination.
HPV, mpox and 4CMenB eligibility depends on age, risk, immune status, prior doses and the current national commissioning route.
A partner controlling barrier use, contraception, medicines or appointments may make a standard plan unsafe or impossible.
03Baseline assessmentMeasurements that guide the plan and track progress.
Read from the initial assessment onwards. Tests may run in parallel in urgent care; first-line, preferred, confirmatory, definitive and gold-standard labels appear only when the chapter explicitly states them.
- 01
Exposure and prevention assessmentFirst step - Why
- Match barriers, testing, PrEP or PEP, contraception and vaccines to actual practices and goals.
- Interpretation and limitations
- Identity alone is not eligibility or exposure evidence; record anatomical sites, timing, partner information and patient preference.
- 02
Site- and time-specific STI testing - Why
- Detect infection and define when an early negative needs repetition.
- Interpretation and limitations
- A negative test applies only to the sampled site, pathogen, assay and reliable window; symptoms can require additional evaluation.
- 03
Hepatitis B history and serology - Why
- Establish vaccination, infection and post-exposure needs when risk is present.
- Interpretation and limitations
- Interpret antigen and antibody patterns with vaccine records, source status and timing; specialist advice guides immunoglobulin and follow-up.
- 04
HIV PrEP or PEP baseline assessment - Why
- Identify infection, renal safety, pregnancy considerations and the suitable prevention pathway.
- Interpretation and limitations
- A qualifying recent exposure goes to PEP urgently; possible acute HIV requires expert assessment because a baseline negative may be too early.
- 05
Vaccine eligibility review - Why
- Check HPV, hepatitis, mpox and gonorrhoea offers against current programme rules.
- Interpretation and limitations
- Age, risk, immune status, prior doses and UK nation determine the offer; previous infection does not necessarily remove all vaccine benefit.
04InterventionsLifestyle, treatment and escalation options.
01Prevention planBuild complementary layersFirst stepAn adult has new partners, sometimes uses condoms and wants to reduce HIV, STI and pregnancy risk.+
- 1Ask about sites, timing, barriers, pregnancy potential, consent, previous tests, HIV prevention, vaccines and the patient’s main goal.
- 2Agree correct barrier use and supplies, site-specific testing and contraception, then assess PrEP eligibility and vaccination gaps.
- 3Explain residual risk and what to do after breakage, symptoms or a recent exposure, including urgent PEP or emergency contraception access.
- 4Arrange a confidential follow-up date to review results, vaccine doses, adherence, side effects, partners and whether the plan is workable.
02Recent exposurePrioritise interventions that expireCondomless sex occurred recently and HIV, pregnancy or hepatitis B exposure is possible.+
- 1Establish the exact time, anatomical exposure, source information, pregnancy potential and whether the contact was wanted.
- 2Route immediately for HIV PEP and emergency contraception assessment and obtain hepatitis B specialist advice when the source context indicates.
- 3Take useful baseline tests, schedule window-period repeats and revisit ongoing prevention after emergency action.
03Vaccine reviewVerify programme and dose historyThe patient requests every vaccine offered by a sexual-health service.+
- 1Check age, anatomy-independent exposure risk, immune status, previous infection and documentary dose history.
- 2Apply the current hepatitis B and HPV guidance and the relevant nation’s mpox or gonorrhoea programme rather than promising a uniform UK offer.
- 3Record the product, dose and next appointment and continue barriers, testing and HIV prevention because protection is incomplete.
05Targets, monitoring and follow-upResponse, safety and longer-term review.
- Review whether the agreed barrier method is available, acceptable and being used correctly, addressing breakage and lubricant problems without blame.
- Track every vaccine product and dose against the correct schedule, immune status and responsible UK-nation programme.
- Monitor PrEP through the current regimen-specific HIV, renal, infection, pregnancy and adherence schedule and reassess changing exposure risk.
- Assign STI and pregnancy results and window-period repeats to a named clinician and confidential communication route.
- Revisit coercion, substance use, partner dynamics, contraception and patient goals because prevention needs change over time.
06Special situationsVariants, exceptions and circumstances that change the usual approach.
Layers answer different risks
Condoms, PrEP, vaccination, contraception, testing and partner care protect against overlapping but non-identical outcomes. HIV PrEP reduces HIV risk when taken correctly; it does not prevent pregnancy or other STIs. Barriers, site-specific testing, vaccination and contraception remain relevant for those other risks according to exposure and personal goals.
Vaccines do not clear infection
An eligible vaccine can reduce future disease while existing symptoms or infection still need diagnosis and treatment.
Programme is not geography free
An England-commissioned vaccine offer cannot automatically be promised through Scottish, Welsh or Northern Irish services.
Barrier technique matters
Late application, early removal, oil damage and poor fit can undermine protection despite reporting condom use.
Control can block prevention
Reproductive or sexual coercion may require discreet care and safeguarding rather than more persuasive counselling.
07Common pitfallsFrequent interpretation and management errors.
- 01
Presenting condoms, PrEP or vaccination as complete protection against every STI and pregnancy.
- 02
Waiting for screening results before arranging urgent HIV PEP, emergency contraception or hepatitis B post-exposure advice.
- 03
Promising England’s targeted 4CMenB gonorrhoea vaccine through every UK service without checking national implementation.
- 04
Assuming every adult HPV candidate needs the same number of doses regardless of age, HIV or immunosuppression.
- 05
Giving generic safer-sex advice without discussing anatomical sites, lubricant, breakage, consent and the patient’s goals.
- 06
Overlooking reproductive coercion or a partner’s control of clinic access, condoms, contraception or medicines.