This Early Symptom is One You Should Watch for With Omicron Infections Rising

If you've been exposed to someone with COVID and are watching for symptoms, what are some of the first signs you might be infected?

It's a question many are asking as omicron cases surge across the country and as the Centers for Disease Control and Prevention update their quarantine and isolation guidelines, which now differ depending on whether or not you have a symptomatic infection.

Here's what we know so far:

Sore throat continues to be a symptom reported, particularly in mild breakthrough infections, health officials say. Those with any flu- or cold-like symptoms should assume they have COVID until proven otherwise.

What are the other symptoms to watch for after COVID exposure?

With some omicron cases, particularly breakthrough infections in those who are boosted and vaccinated, remaining mild, many are wondering how to tell if it's a cold, the flu or COVID-19.

Those who are fully vaccinated aren't necessarily getting seriously ill and having fevers for days and difficult breathing, but are instead experiencing a more mild illness, similar to a cold. But they still have the ability to transmit the virus to others.

Those who are unvaccinated, however, are experiencing similar symptoms to early on in the pandemic, health officials said.

Dr. Katherine Poehling, an infectious disease specialist and member of the Advisory Committee on Immunization Practices, told NBC News last week that a cough, congestion, runny nose and fatigue appear to be prominent symptoms with the omicron variant. But unlike delta, many patients are not losing their taste or smell.

The evidence so far, according to Poehling, is anecdotal and not based on scientific research. She noted also that these symptoms may only reflect certain populations.

Still, CDC data showed the most common symptoms so far are cough, fatigue, congestion and a runny nose.

Overall, the symptoms for COVID reported by the CDC include:

• Fever or chills
• Cough
• Shortness of breath or difficulty breathing
• Fatigue
• Muscle or body aches
• Headache
• New loss of taste or smell
• Sore throat
• Congestion or runny nose
• Nausea or vomiting
• Diarrhea

The CDC also has what it calls a "coronavirus self checker" that allows people to answer a series of questions to determine if they should seek medical care.

"The Coronavirus Self-Checker is an interactive clinical assessment tool that will assist individuals ages 13 and older, and parents and caregivers of children ages 2 to 12 on deciding when to seek testing or medical care if they suspect they or someone they know has contracted COVID-19 or has come into close contact with someone who has COVID-19," the CDC's website reads.

Here's how to use it.

How soon might COVID symptoms appear?

According to earlier CDC guidance, COVID symptoms can appear anywhere from two to 14 days after someone is exposed to the virus.

Anyone exhibiting symptoms should get tested for COVID-19.

Some people may never experience symptoms, though they can still spread the virus.

A person is also considered contagious before symptoms appear.

When are people with COVID most contagious?

The CDC says that its guidelines were updated to reflect growing evidence that suggests transmission of COVID-19 often occurs one to two days before the onset of symptoms and during the two to three days afterward. 

For those without symptoms, CDC guidance states they are considered contagious at least two days before their positive test.

When should you call a doctor?

The CDC urges those who have or may have COVID-19 to watch for emergency warning signs and seek medical care immediately if they experience symptoms including:

• Trouble breathing
• Persistent pain or pressure in the chest
• New confusion
• Inability to wake or stay awake
• Pale, gray, or blue-colored skin, lips, or nail beds, depending on skin tone

"This list is not all possible symptoms," the CDC states. "Please call your medical provider for any other symptoms that are severe or concerning to you."

You can also notify the operator that you believe you or someone you are caring for has COVID.

How long after COVID exposure could you test positive?

According to the CDC, the incubation period for COVID is between two and 14 days, though the newest guidance from the agency suggests a quarantine of five days for those who are not boosted, but eligible or unvaccinated. Those looking to get tested after exposure should do so five days after the exposure or if they begin experiencing, the CDC recommends.

Those who are boosted and vaccinated, or those who are fully vaccinated and not yet eligible for a booster shot, do not need to quarantine, but should wear masks for 10 days and also get tested five days after the exposure, unless they are experiencing symptoms.

Still, for those who are vaccinated and boosted but are still looking to be cautious, health experts say an additional test at seven days could help.

When is the best time to get tested after exposure?

The CDC states that anyone who may have been exposed to someone with COVID should test five days after their exposure, or as soon as symptoms occur.

"If symptoms occur, individuals should immediately quarantine until a negative test confirms symptoms are not attributable to COVID-19," the guidance states.

Though the incubation times could be changing, experts still advise those who test early to continue testing even if they get negative results.

How long should you quarantine or isolate?

First things first, those who believe they have been in contact with someone who has COVID and are unvaccinated should quarantine. Those who test positive, regardless of vaccination status, must isolate, according to the Centers for Disease Control and Prevention.

Here's the difference between the two:

Quarantine

Those who have been within six feet of someone with COVID for a cumulative total of at least 15 minutes over a 24-hour period should quarantine for five days if unvaccinated, or if they are more than six months out from their second vaccine dose, according to updated CDC guidance issued Monday.

Once that period ends, they should partake in strict mask use for an additional five days.

Previously, the CDC said people who were not fully vaccinated and who came in close contact with an infected person should stay home for at least 10 days.

Prior to Monday, people who were fully vaccinated — which the CDC has defined as having two doses of the Pfizer or Moderna vaccines, or one dose of the Johnson & Johnson vaccine — could be exempt from quarantine.

Those who are both fully vaccinated and boosted do not need to quarantine if they are a close contact of someone with COVID, but should wear a mask for at least 10 days after exposure. The same goes for those who are fully vaccinated and not yet eligible for their booster shot.

Isolation

People who are positive for COVID should stay home for five days, the CDC said Monday, changing guidance from the previously recommended 10 days.

At the end of the period, if you have no symptoms, you can return to normal activities but must wear a mask everywhere — even at home around others — for at least five more days.

If you still have symptoms after isolating for five days, stay home until you feel better and then start your five days of wearing a mask at all times.

So how do you calculate your isolation period?

According to the CDC, "day 0 is your first day of symptoms." That means that Day 1 is the first full day after your symptoms developed.

For those who test positive for COVID but have no symptoms, day 0 is the day of the positive test. Those who develop symptoms after testing positive must start their calculations over, however, with day 0 then becoming the first day of symptoms.

Do you need to test out of isolation or quarantine?

Isolation

For those who test positive for COVID and isolate for the required five-day period without symptoms, there is not currently a requirement to test before you see people again, according to the most recent CDC guidance.

"If an individual has access to a test and wants to test, the best approach is to use an antigen test towards the end of the five-day isolation period," the CDC guidance states. "If your test result is positive, you should continue to isolate until day 10. If your test result is negative, you can end isolation, but continue to wear a well-fitting mask around others at home and in public until day 10."

The advice for those who tested positive and experienced symptoms also does not indicate a testing requirement, but rather, the person must remain "fever-free for 24 hours without the use of fever-reducing medication" and other symptoms should have improved before they end their isolation, which must last a minimum of five days.

Both symptomatic and asymptomatic people should continue wearing masks around others for an additional five days, the guidance states.

Quarantine

For those in quarantine, however, the guidance is different.

According to the CDC, those exposed to COVID who develop symptoms should test immediately and enter isolation protocols until they receive their results and if they positive.

Those who do not develop symptoms should get tested at least five days after their exposure and, if negative, can leave their home but should continue masking until the 10-day mark.

Why don't you need to test out of isolation?

The CDC notes that tests "are best used early in the course of illness to diagnose COVID-19 and are not authorized by the U.S. Food and Drug Administration to evaluate duration of infectiousness."

"While a positive antigen test likely means a person has residual transmissible virus and can potentially infect others, a negative antigen test does not necessarily indicate the absence of transmissible virus," the CDC's website reads. "As such, regardless of the test result, wearing a well-fitting mask is still recommended."

The CDC's most recent guidance came as many experts expected a testing requirement to be added, but it also comes at a time when testing shortages are being reported nationwide.

"I do not think that the clarification helped at all and I actually think that it made things worse," emergency physician Dr. Leanna Wen, the former health commissioner of Baltimore, said in an interview with CNN. "I think they should be upfront and say they can't do this because they don't have enough tests."

What kind of test should you use if you do want to test before leaving isolation?

The CDC recommends antigen testing for those looking to test before leaving isolation.

But Massachusetts updated its testing guidance Tuesday, with Gov. Charlie Baker saying that at-home tests are now acceptable in most cases.

The DPH guidance, the governor said, makes clear that in most cases rapid antigen tests should suffice for schools, employers and child care centers who require people to get tested in order to return after exposure or infection, and that PCR tests should not be required.

"Rapid tests, in most situations, are a very good alternative to PCR tests," Baker said.

What if you test positive using an at-home test?

Those who test positive using an at-home test are asked to follow the latest CDC guidelines and communicate the results to their healthcare provider, who is responsible for reporting test results to the state health department.

According to health experts, people should assume the test results are accurate and should isolate from others to reduce the risk of spreading the virus.

When can you be around other people after having COVID?

If you had symptoms, the CDC says you can be around others after you isolate five days and stop exhibiting symptoms. However, you should continue to wear masks for the five days following the end of symptoms to minimize the risk to others.