Will a work trip to Poland mean I have to isolate for 90 days?

I have to travel to Poland for work in a fortnight. New travel rules mean I will have to take a Covid PCR test on day two of my return. However, the Department of Health and Social Care (DHSC) website states that PCR tests can’t be taken within 90 days of testing positive for Covid. I had the virus a month ago. I can’t find any guidance on what I should do.
RD, Hastings, east Sussex

You raise a question that affects hundreds of thousands of people, and the DHSC guidance for international arrivals is silent on the issue. Test and trace advises against taking a PCR, or lateral flow test, within 90 days of a Covid diagnosis, because residual inactive viral fragments may give a positive result for up to three months after the infection risk has disappeared.

Only on Wednesday did the UK Health Security Agency, which replaced Public Health England in October, shed light on the problem, but only near the end of guidance for those who have come into contact with someone who has tested positive. It states that while the 90-day advice usually applies to recent Covid sufferers, they have to take a PCR test when returning to the UK from overseas. Given that the new rules oblige travellers to quarantine until they receive a negative result, this could mean three months of self-isolation.

The NHS Covid pass app records natural immunity, which is thought to last up to 180 days following infection. Although this should be acceptable in places such as care homes, which usually require a negative test result, it carries no weight for new arrivals in the UK. Your trip could leave you stuck at home until next year so, if at all possible, I’d cancel it.

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