Researchers estimate that people who get infected with the coronavirus can spread it to others 2 to 3 days before symptoms start and are most contagious 1 to 2 days before they feel sick.
Symptoms may appear 2-14 days after exposure to the virus. Anyone can have mild to severe symptoms. Possible symptoms include: Fever or chills.
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.
We compared serial intervals and incubation periods for SARS-CoV-2 Omicron BA. 1 and BA. 2 subvariants and Delta variants in Singapore. Median incubation period was 3 days for BA. 1 versus 4 days for Delta.
The incubation period appears to be even shorter – about three days – for the Omicron variant. We know that people tend to be most infectious early in the course of their infection.
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.
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.
You are considered contagious from two days before your symptoms begin until 10 days after your symptoms began. If you have no symptoms, you are considered contagious beginning two days before your test sample was collected and until 10 days after your test sample was collected.
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.
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.
Common Symptoms
Fever or chills. A dry cough and shortness of breath. Feeling very tired. Muscle or body aches.
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.
If you are significantly immunosuppressed, you are more likely to be infectious for longer than 7 days and may still be able to spread the virus. Follow these measures until day 14 following your positive test result to further reduce any remaining risk of spreading the virus.
And research done by the CDC shows about half of people were still testing positive on the antigen test between five and nine days after symptom onset or diagnosis.
Even if mild symptoms remain, you are likely not contagious after 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.
People with COVID-19 can spread the virus to other people starting two days before they develop symptoms (or 2 days before the date of their positive test if they do not have symptoms) through 10 days after they develop symptoms (or 10 days after the date of their positive test if they do not have symptoms).
Antibodies and other viruses
Keep in mind that if a person tests negative for COVID-19 but still exhibits symptoms, they may have another virus like the flu or a respiratory syncytial virus (RSV), which a COVID-19 test would not pick up.
You should also isolate if you are sick and suspect that you have COVID-19 but do not yet have test results. If your results are positive, follow the full isolation recommendations below. If your results are negative, you can end your isolation.
Many people who are infected have more mild symptoms like a scratchy throat, stuffy or runny nose, occasional mild cough, fatigue, and no fever. Some people have no symptoms at all, but they can still spread the disease.” Fever seems to be one of the more common early markers of COVID-19, Kline noted.
On June 30, the Centers for Disease Control and Prevention added three symptoms to its COVID-19 list: Congestion/stuffy nose, nausea and diarrhea. Those three new conditions now join other symptoms identified by the CDC: Fever.
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.
Symptom onset
The first symptoms of COVID-19 can be more gradual. While COVID-19 symptoms can develop as early as two days after you're infected, the Centers for Disease Control and Prevention (CDC) says five days after infection is typical.
Gradually build up exercise – seize the time when you are feeling less tired and go for a short walk – but you MUST still avoid any contact with others. However, at this stage lookout for breath related symptoms (see below what to look for).
The COVID-19 infection period varies from person to person. Most people with COVID-19 will have a mild illness and will recover in a few days. Generally, people with COVID-19 are considered infectious from 48 hours before symptoms start.