Vaccinated People Appear To Be Less Contagious
So, while the true answer to how long people with breakthrough infections are contagious is we dont really know yet, scientists have learned a few things.
A study from Singapore found that although the viral loads for vaccinated and unvaccinated people had similar peaks at the start of the infection, the viral loads in vaccinated people dropped much more rapidly compared to unvaccinated people. The viral load in vaccinated people dropped to levels that are generally believed to be not infectious around six days after the the onset of illness. Meanwhile, the viral load in unvaccinated people dropped to that same level at the 10-day mark.
A Harvard study similarly found that vaccinated people appear to clear the virus in 5½ days versus unvaccinated people who cleared it out in 7½ days. Another report from the University of Illinois found more of the same. Vaccinated people clear it from the upper airway faster, so they are less contagious, said Adam Ratner, the director of pediatric infectious diseases and a member of the Vaccine Center at New York University Langone Health.
Researchers from the Netherlands took it a step further and looked at respiratory samples taken from vaccinated people with breakthrough infections and found that the virus in their noses was less likely to be infectious compared to unvaccinated people who got COVID. Still, infectious virus was detected in 68% of the vaccinated participants .
Looking At Past Pandemics
Many researchers believe may never actually see the âendâ of COVID-19, but instead, COVID-19 will become an endemic source, such as the flu virus, meaning itâll circulate even when the pandemic ends. This is based on experiences from the last four pandemics, H1N1, H2N2, H3N2, and the Spanish Flu. These pandemics all ended because these viruses went through a transition where they became milder illnesses. Depending on the speed to reach herd immunity via vaccination or natural infection, each state will vary. Once a state reached 75-85% herd immunity, itâs likely cases will be low enough for a return to normal life.
A Pandemic With Multiple Endings
How COVID-19 will end will vary from one country to another, depending largely on the proportion of people immunised and how much infection has occurred since the start of the pandemic.
In the UK and other countries with high vaccine coverage and also high numbers of past cases, most people will have some form of immunity to the virus. In England, for example, its estimated that at the beginning of September over 94% of the adult population had COVID-19 antibodies.
Among those with prior immunity, its been shown that COVID-19 tends to be less severe. And as more peoples immunity is boosted over time by natural reinfections or booster immunisations, we can expect an increasing proportion of new infections to be asymptomatic or at worst cause mild illness. The virus will remain with us, but the disease will become part of our history.
But in countries without much prior illness, even with high vaccine coverage, many people will remain susceptible. Even in countries with the highest vaccine coverage worldwide over 10% of people are yet to receive a vaccine. Virtually everyone who has not been vaccinated is likely to catch the virus. When infected, they will be as much at risk of severe disease and death as at any time during the pandemic.
Recommended Reading: Did Hank Aaron Get Covid Vaccine
How We Determine Covid Infectiousness
Scientists have been evaluating infectiousness by looking at the amount of the virus detected in peoples noses. A persons nose is swabbed with a PCR test kit, which tells us two things: if virus is present and, if so, an estimate of how much virus is present . But what the PCR doesnt tell us is how infectious that virus is. Usually, with other diseases, when we want to measure infectiousness, we culture the virus from a persons nose to see if its alive or not.
A PCR just amplifies the sequence of virus but in no way tells if its alive or healthy and can go from one person to the next,Gandhi said.
According to Gandhi, the best way to understand how contagious vaccinated people with breakthrough infections are would be through contact tracing. With tracing studies, you could actually see if and when vaccinated people spread the virus to others.
But we dont have many contract-tracing studies looking at breakthrough cases and transmission events yet. Many of the insights we have on the contagiousness of breakthrough cases are gleaned from laboratory studies and PCR tests that usually only tell us if theres virus in a persons body, not whether its infectious and for how long it might be infectious.
How Many People Get Long Covid
New evidence has been emerging that a number of COVID patients continue to experience symptoms for weeks or months after the initial diagnosis. It seems around 1 in 20 continue to have symptoms long term.
One Italian study reported that after hospital discharge, by 60-days from the onset of the infection:
- 87.4% of people still had at least one symptom most commonly breathlessness and fatigue.
- 13% were symptom-free.
- 32% reported one or two symptoms.
- 55% reported three or more symptoms.
Around two-thirds of patients said they had a reduced quality of life.
A research team at King’s College, London, have been collecting information about COVID-19 symptoms using a specially designed mobile phone app. It is now becoming apparent from the use of this data, that although most people are only unwell with COVID for 14 days, around one in ten remains unwell for 3 weeks or longer.
Recommended Reading: How Long Cvs Covid Test Results
I Think Or Know I Had Covid
You can be around others after:
- 10 days since symptoms first appeared and
- 24 hours with no fever without the use of fever-reducing medications and
- Other symptoms of COVID-19 are improving*
*Loss of taste and smell may persist for weeks or months after recovery and need not delay the end of isolation
Note that these recommendations do not apply to people with severe COVID-19 or with weakened immune systems .
How Long Can Long Covid Last
Long COVID is said to be present if you’ve had COVID-19 infection, but still have symptoms after 8 weeks. Dr. Tim Spectre and his colleagues at King’s College Hospital have collected data about COVID symptoms using a specially designed app. From this, they have discovered that when infected with COVID
- 1 in 7 had symptoms for 4 weeks
- 1 in 20 had symptoms for 8 weeks
- 1 in 50 had symptoms for 12 weeks or more.
- Many still have symptoms after 9 months or more.
They estimated the risk of Long COVID at around 1 in 20 of those who become infected.
Also Check: Cvs Covid Testing Results Time Frame
For Anyone Who Has Been Around A Person With Covid
Anyone who has had close contact with someone with COVID-19 should stay home for 14 days after their last exposure to that person.
However, anyone who has had close contact with someone with COVID-19 and who meets the following criteria does NOT need to stay home.
- Someone who has been fully vaccinated and shows no symptoms of COVID-19. However, fully vaccinated people should get tested 3-5 days after their exposure, even if they dont have symptoms and wear a mask indoors in public for 14 days following exposure or until their test result is negative.
- Someone who has COVID-19 illness within the previous 3 months and
- Has recovered and
- Remains without COVID-19 symptoms
What Is ‘viral Persistence’ And How Does That Affect The Course Of The Disease
Sometimes the coronavirus sticks around longer than expectedand scientists are still trying to figure out why that happens in some patients, how it varies by individual, and exactly how long the virus stays alive inside the body. This is known as viral persistence, and it affects how long someone is contagious and therefore how long they should stay in isolation.
Recommended Reading: How Long Cvs Covid Test Results
The Problem With Covid
Viruses mutate as they spread, resulting in new variants of COVID-19. Not all variants are problematic, but some are more infectious and can cause more severe illnesses than others. The problem with COVID-19 variants is that we do not know which variants we are protected against through vaccination. At this time, all Food and Drug Administration authorized vaccines are effective against hospitalization and death, but they do not necessarily prevent the spread of COVID-19.
I Was Severely Ill With Covid
People who are severely ill with COVID-19 might need to stay home longer than 10 days and up to 20 days after symptoms first appeared. People with weakened immune systems may require testing to determine when they can be around others. Talk to your healthcare provider for more information. Your healthcare provider will let you know if you can resume being around other people based on the results of your testing.
People who are immunocompromised should be counseled about the potential for reduced immune responses to COVID-19 vaccines and the need to continue to followcurrent prevention measures to protect themselves against COVID-19 until advised otherwise by their healthcare provider. Close contacts of immunocompromised people should also be encouraged to be vaccinated against COVID-19 to help protect these people.
You May Like: How Long Does It Take To Get Cvs Covid Results
After Vaccination: We Have To Wait To Prove That Its Working
Its 2021, and youve just gotten your two doses. What happens next will largely depend on two factors: How effective the vaccine is and how many people get it.
The goal is for the vaccine to be effective and widespread enough for the U.S. population to reach the herd immunity thresholdthe point at which, theoretically, Americans can safely take off their masks and attend large sporting events. A rough, back-of-the-envelope estimate for Covid-19 is that society will reach herd immunity when around 60 percent to 70 percent of the population is immune.
Paul Offit, director of the Vaccine Education Center at Childrens Hospital of Philadelphia, walked through the math: Roughly, the formula would state that about two-thirds of the population would need to be vaccinated if was 75 percent effective against shedding the virus. If the vaccine is less effective than that, a greater percentage of the population needs to get vaccinated to close in on herd immunity. And vice versa.
A volunteer receives an injection as the world’s biggest study of a possible Covid-19 vaccine, developed by the National Institutes of Health and Moderna Inc., gets underway in July in Binghamton, N.Y. | AP Photo/Hans Pennink
Nor has the FDA set the bar very high: The agency indicated that any approved vaccine must prevent Covid-19 or decrease severity in at least 50 percent of those vaccinated, but that means more than 50 percent of the population could continue to transmit the disease.
- Filed Under:
Risk Factors For Long Covid Include
- Older age Long COVID affects 10% of 18-49 year-olds but this increases to 22% of those aged over 70.
- Obesity Long COVID is slightly more common if you have a raised BMI.
- Sex In younger age groups, long COVID is more common in women than men.
- Asthma This appears to be linked.
- Symptoms Having lots of symptoms early in the infection.
Dr. Spectre has suggested Long COVID can be divided into two groups. One group who have mostly long term respiratory symptoms with chronic cough, shortness of breath and tiredness. The second group has more organ-specific symptoms such as brain fog and other neurological symptoms, heart damage and kidney failure.
At the time of writing, 54 million people have been infected with the COVID-19 virus worldwide. If 1 in 20 develops Long COVID, this represents a huge new disease burden worldwide.
You May Like: How Much Is Covid Test At Cvs
This Is How Long The Delta Variant Covid Surge Will Last Data Shows
Researchers have projected exactly when the variant’s surge will hit its peak.
The Delta variant seems to have knocked the U.S. off its path of ending the COVID pandemic. As a result of this fast-spreading variant, virus cases are spiking, ICUs are filling up, and officials are considering bringing back mask mandates. According to the Centers for Disease Control and Prevention , COVID cases have increased by nearly 50 percent in the last weekand more than 80 percent of these new cases are caused by infections with the Delta variant, which is currently the predominant variant in the country. Now, researchers have predicted just how long the Delta variant COVID surge will last.
The COVID-19 Scenario Modeling Hub, a group of researchers working with the CDC to help track the course of pandemic, released new projections on July 21, detailing the course of the spike in coronavirus cases. The researchers created four possible scenarios for its projections, changing based on what percent of the U.S. population gets vaccinated and how quickly the Delta variant spreads.
“By the time you get to October, these resurgent epidemics have burned through a lot of the people who are susceptible,” Lessler explained.
Moderna Maintained Efficacy Up To 5 Months
A recent study by Brigham and Womens Hospital researchers concluded that the Moderna COVID-19 vaccine was 93 percent effective at preventing illness, and more than 98 percent effective for preventing severe illness even 5 months after a second dose.
The vaccine trial included 30,415 participants, with 15,209 receiving Modernas vaccine and 15,206 given a placebo.
According to researchers, the Moderna vaccine showed continued effectiveness at preventing COVID-19 and severe illness even after 5 months, while maintaining an acceptable safety profile and protection against asymptomatic infection.
The message here is not that if you were vaccinated early, youre not protected. Those vaccinated more recently may be experiencing a marginal improvement, co-corresponding author Lindsey Baden, MD, division of infectious diseases at BHW said in a statement. But both groups are benefiting from protection compared to people who remain unvaccinated.
Waning immunity happens to some extent with all vaccines, but that does not mean that the vaccines stop working completely, David Hirschwerk, MD, an infectious disease specialist with Northwell Health in Manhasset, New York, told Healthline.
But their effectiveness often reduces as times moves along, he continued.
He emphasized that COVID-19 vaccines remain very effective at preventing severe illness well beyond 6 months.
But they become steadily less effective at preventing any degree of infection.
You May Like: How Long Cvs Covid Test Results
Open Borders May Take Longer
The COVID-19 crisis is a global one, but the responses are often much more localized.
Many countries have closed their borders to foreign travellers as the pandemic has spread, attempting to manage the situation among their own population without introducing potential complications from abroad.
But this creates a new challenge, as some countries have been able to pass the peak of their outbreaks while virus activity has only begun to ramp up elsewhere. As a result, countries may choose to keep border restrictions in place long after they have beaten back COVID-19, waiting for the rest of the world to do the same.
“We’ll likely have to be very careful there,” Bogoch said.
“I would imagine that even when policies are starting to be lifted, there will likely be significant restrictions on international travel if it’s allowed.”
Even if borders are opened, travellers will face a double dose of risk: the chance they’ll pick up the virus while they’re away, and the chance they’ll spread it to others after they return home.
Canadian authorities seem to be preparing for these possibilities. At a press conference in Ottawa on Tuesday, Health Minister Patty Hajdu said a “global solution” will be necessary, no matter what actions Canada takes on its own.
“Viruses and bugs have a way of making their way around human populations,” she said.
“If there is one case of COVID-19, then we’re all at risk.”
Listen To This Article
On Jan. 9, 2020, about a week after the world first learned of a mysterious cluster of pneumonia cases in central China, authorities announced that scientists had found the culprit: a novel coronavirus.
It was a sobering announcement, and an unnervingly familiar one. Nearly two decades earlier, a different coronavirus had hurdled over the species barrier and sped around the world, causing a lethal new disease called severe acute respiratory syndrome, or SARS. The virus, which became known as SARS-CoV, killed 774 people before health officials contained it.
But even as scientists worried that history might be repeating itself, there was one glimmer of hope. Although all viruses evolve, coronaviruses are known to be relatively stable, changing more slowly than the common flu.
There was, I think, a sense that would work in our favor, and that the nightmare scenario of it being like influenza constantly changing and needing updated vaccines all the time would probably not be the case, said Dr. Adam Lauring, a virologist and infectious disease physician at the University of Michigan.
What many scientists had not counted on was unchecked global spread. Over the following weeks, the new virus, SARS-CoV-2, skipped from Wuhan, China, to a cruise ship in Japan, a small town in northern Italy and a biotechnology conference in Boston. Country by country, global coronavirus trackers turned red.