How long are you infectious with Covid? When virus is most contagious - how long it lasts after positive test

More than two million people in the UK were estimated to have had the Covid in the week to 30 June, marking the highest estimate since late April.

The recent rise in infections has been driven by the Omicron BA.4 and BA.5 variants, which are now dominant in the UK and are more transmissible than previous strains.

Health experts say there is “currently no evidence” that the subvariants can cause more serious illness, but people have been warned to be cautious and are urged to wear face masks in crowded and enclosed spaces after warnings the current wave has not yet peaked.

Professor Tim Spector, lead scientist behind the ZOE Covid study, also warned that the range of symptoms being reported is changing as more people are infected with the newest strains.

Data from the study now shows a sore throat is the most common sign of infection, while the more “old fashioned” symptoms have dropped much further down the rankings, including a fever, and a loss or change to sense of smell or taste.

Professor Spector said: “If you’re not testing, you should assume it’s Covid at the moment because it’s far more prevalent than anything else out there.

“It’s much more likely to be Covid than a summer cold.”

If you feel unwell, here’s what you need to know about symptoms, how long infection from Covid will usually last, and when you are most infectious.

How long does Covid last for?

Symptoms of Covid typically last around five days on average, after which you should start to feel better.

However, in some cases recovery can take longer, with some people still experiencing some effects for several weeks. If symptoms last for more than 12 weeks, this is known as ‘long Covid’.

The NHS states: “The course of recovery does not appear to be related to the severity of the initial infection.

“Many people make a full recovery within 12 weeks but some people do not.

“For some people, symptoms can persist for longer than 12 weeks and may change over time and new symptoms may develop.”

How long will I be contagious?

People who have tested positive for Covid can pass the virus to others from around two days before they start to display symptoms.

Those infected can then remain contagious for up to 10 days after symptoms appear, according to the UK government.

It is possible to spread the virus to others even if symptoms are mild, or if you do not have any at all, which is why self-isolation is so important in reducing transmission.

When is Covid most infectious?

Findings from a study published in The Lancet Microbe last year suggested that people are most infectious in the first five days after the onset of symptoms.

However, more recent research, published in JAMA Internal Medicine, found that people are most infectious two days before and three days after developing symptoms.

The European Centre for Disease Prevention and Control (ECDC) said that adults with mild to moderate symptoms remain infectious no longer than 10 days after symptoms begin, regardless of the variant.

But adults with severe to critical illness, or severe immunosuppression, can remain infectious for up to 20 days after symptoms start.

However, if you are fully vaccinated you are likely to be less infectious. Evidence suggests people who catch Covid and have been double jabbed can have comparable amounts of the virus in their body as someone who is unvaccinated, but they are less contagious overall.

What are the symptoms of Covid?

The range of symptoms being reported is becoming more varied as more people are infected with the BA.4 and BA.5 strains.

The top 20 most reported Covid symptoms to look for right now, according to data from the ZOE Covid Study app, are:

• Sore throat
• Headache
• Blocked nose
• Cough no phlegm
• Runny nose
• Cough with phlegm
• Hoarse voice
• Sneezing
• Fatigue
• Muscle pains/aches
• Dizzy light-headed
• Swollen neck glands
• Eye soreness
• Altered smell
• Chest pain tightness
• Fever
• Chills or shivers
• Shortness of breath
• Earache
• Loss of smell

If you feel unwell or experience any Covid symptoms, it is advised that you stay at home and avoid contact with others where possible. In most cases, symptoms should start to go away in around five days.