We know that people tend to be most infectious early in the course of their infection. With Omicron, most transmission occurs during the one to two days before onset of symptoms, and in the two to three days afterwards.
You can also spread COVID-19 in the 48 hours before your symptoms start. If you never have symptoms, consider yourself most infectious in the 5 days after you test positive.
When do omicron subvariant symptoms start? The time it takes for an infected person to develop symptoms after an exposure is shorter for the omicron variant than for previous variants — from a full week down to as little as three days or less, according to the Centers for Disease Control and Prevention.
The mean virus incubation period during the SARS-CoV-2 Omicron BA. 5-dominant period in Japan was 2.6 (95% CI 2.5-2.8) days, which was less than during the Delta-dominant period. Incubation period correlated with shared meals and adult infectors. A shorter incubation suggests a shorter quarantine period for BA.
If you do not have symptoms but have been exposed to COVID-19, wait at least 5 full days after your exposure before taking a test. If you are only going to take a single test, a PCR test will provide a more reliable negative test result.
The mean virus incubation period during the SARS-CoV-2 Omicron BA. 5–dominant period in Japan was 2.6 (95% CI 2.5–2.8) days, which was less than during the Delta-dominant period. Incubation period correlated with shared meals and adult infectors. A shorter incubation suggests a shorter quarantine period for BA.
The Delta variant's was 4.41 days. And Omicron's has been 3.42 days. Taken all together, the average incubation period of COVID between December 1, 2019, and February 10, 2022, was 6.57 days. Even though the incubation period is shorter, COVID-19 still has a longer incubation period than other respiratory infections.
BMJ: “Covid-19: Runny nose, headache, and fatigue are commonest symptoms of omicron, early data show.”
You may need to get tested even if you do not have symptoms. You can have COVID-19 and spread it to others even if you do not have symptoms. Your COVID-19 test can be negative even if you are infected. Most people do not test positive for the virus until days after exposure.
People with moderate or severe COVID-19 should isolate through at least day 10. Those with severe COVID-19 may remain infectious beyond 10 days and may need to extend isolation for up to 20 days.
Most often, common cold symptoms start 1 to 3 days after someone is exposed to a cold virus. Symptoms vary. They can include: Runny or stuffy nose.
Your infectious period
The COVID-19 infectious period can vary, but most people are considered infectious from 48 hours before their symptoms start and can be infectious for up to 10 days.
How long do omicron symptoms last? Most people who test positive with any variant of COVID-19 typically experience some symptoms for a couple weeks. People who have long COVID-19 symptoms can experience health problems for four or more weeks after first being infected, according to the CDC.
You are contagious for the entire period of time symptoms are present, all the way until they disappear.
Some people can test positive for COVID-19 for weeks or even months on PCR tests, but there is good news: people are not likely to be contagious for that long from a single infection, even if they test positive, and therefore are unlikely to transmit the virus to others.
Symptoms of Omicron can be similar to the original COVID-19 virus and other variants, which can include a combination of the following: fever, cough, congestion, runny nose, headache, sore throat, muscle pains/aches and fatigue. “Fever, cough and headache look to be the most common symptoms from the current data.
While many people assumed that getting infected meant higher protection from future encounters with the virus, the latest wave of COVID-19 cases shows that reinfections are becoming more common with newer variants—such as the XBB. 1.5 subvariant of Omicron—contributing to second or even third infections.
If you test positive for COVID-19 and have no symptoms – you may end after day 5. If you test positive for COVID-19 and have symptoms – you may end after day 5 if: You are fever-free for 24 hours (without the use of fever-reducing medication) Your symptoms are improving.
How does the Omicron variant spread? Although it still spreads from person-to-person through air (within 6 feet through respiratory droplets), research shows that the Omicron variant likely spreads easier and faster than the original COVID-19 virus.
You can spread the common cold from a few days before your symptoms appear until all of the symptoms are gone. Most people will be contagious for up to 2 weeks. Symptoms are usually worse during the first 2 to 3 days, and this is when you're most likely to spread the virus.
Symptoms usually begin 1 or 2 days after ingesting the virus, but may appear as early as 12 hours after exposure. The illness typically comes on suddenly. The infected person may feel very sick and vomit often, sometimes without warning, many times a day.
A person may have mild symptoms for about one week, then worsen rapidly. Let your doctor know if your symptoms quickly worsen over a short period of time.
By the 10th day after COVID symptoms begin, most people will no longer be contagious, as long as their symptoms have continued to improve and their fever has resolved. People who test positive for the virus but never develop symptoms over the following 10 days after testing are also probably no longer contagious.
In infected individuals, the peak viral load occurred on day 5, with the virus first detected in the throat and then rising to significantly higher levels in the nose.