Catching Covid once is bad enough, but some people are unlucky enough to catch it again. Here’s everything you need to know about Covid re-infection and how long your immune system protects you from the virus
After a recent spike in cases from the Omicron variant, Covid seems to finally be falling in the UK, where Plan B restrictions are in the process of being scrapped. Despite this, the virus continues to be rampant and risk of infections still remains high.
When someone catches Covid, their immune system usually generates a response that helps their body fight off the virus and protects them from future infections. However, some people end up getting re-infected as their immunity begins to wane.
So, if you’ve recently caught Covid and you’re wondering how long you might remain immune to it before the risk of catching it again – here’s everything you need to know.
How soon can I catch Covid again?
After someone catches Covid, their bodies builds antibodies that help fight against the virus. However, it’s not known how long immunity from infection lasts, and it can also vary from person to person.
A recent Public Health England (PHE) study found that more people who have had coronavirus are protected from catching it again for at least five months.
However, a government website states that a new infection could occur within 90 days – or three months – of being infected once. This would be mean that people who have the virus in October could be vulnerable to catching it again this month.
Sometimes, the immune response doesn’t last as long as five or three months and people end up getting re-infected twice in one month.
The Omicron variant, which has more mutations than previous variants, is thought to be more likely to cause reinfection than variants like Delta. However, UK studies are yet to look into Omicron re-infection rates in more detail.
It’s worth noting that residual signs of Covid infection can show up on a PCR test for up to three months, even if a person is not displaying any symptoms.
Do I need to self-isolate if I’ve already had Covid before?
Yes, if you have symptoms of Covid or have tested positive for the virus, you will need to self-isolate, even if you have already contracted the virus in the past few months.
You will also need to self-isolate if you’ve not been vaccinated and live with someone who has tested positive. This applies even if you have had recently been infected, as this would be a new infection and you are considered contagious again.
Guidelines from Gov.uk state: “If an individual is re-tested 90 days or more after their initial illness onset or prior test date, and is found to be PCR positive, this should be considered as a possible new infection.”