Vaccinated people are less likely to spread Covid, new research finds

[MrStretch]

 

Vaccinated people are less likely to spread Covid, new research finds

British scientists examined how the Pfizer-BioNTech and the AstraZeneca vaccines affected the spread of the virus if a person had a breakthrough infection.

Oct. 2, 2021, 3:39 AM +07

By Akshay Syal, MD

 

 

People who are vaccinated against Covid-19 are less likely to spread the virus even if they become infected, a new study finds, adding to a growing body of evidence that vaccines can reduce transmission of the delta variant.

British scientists at the University of Oxford examined national records of nearly 150,000 contacts that were traced from roughly 100,000 initial cases. The samples included people who were fully or partially vaccinated with either the Pfizer-BioNTech or the AstraZeneca vaccines, as well as people who were unvaccinated. The researchers then looked at how the vaccines affected the spread of the virus if a person had a breakthrough infection with either the alpha variant or the highly contagious delta variant.

Both vaccines reduced transmission, although they were more effective against the alpha variant compared to the delta variant. When infected with the delta variant, a given contact was 65 percent less likely to test positive if the person from whom the exposure occurred was fully vaccinated with two doses of the Pfizer vaccine. With AstraZeneca, a given contact was 36 percent less likely to test positive if the person from whom the exposure occurred was fully vaccinated.

The risk of transmission from a breakthrough infection was much higher if someone had received just dose of either vaccine.

The study was posted online Thursday and hasn’t yet been peer reviewed. But scientists not associated with the research said the findings were credible.

“It’s the highest quality study we have so far on the question of infectiousness of vaccinated people infected with delta,” said Dr. Aaron Richterman, an infectious disease physician at the University of Pennsylvania, who was not involved in the research.

Susan Butler-Wu, a clinical microbiologist at the University of Southern California, called the study “well performed,” especially because it reflects real-world transmission since it tracked spread among close contacts.

Using cycle threshold (Ct) values, the researchers found a similar level of viral load in unvaccinated and vaccinated people who were infected with the delta variant, backing up prior studies. Even so, people who were fully vaccinated were still less likely to infect others.

“Transmission is much more complex,” Butler-Wu said, meaning the Ct value is just a snapshot in time and doesn’t reflect the entire course of illness.

It's likely that people who have been vaccinated clear the infectious virus from the body faster. A previous study from Singapore had found that although levels of the virus were initially the same in those infected with the delta variant regardless of vaccine status, by day seven, levels of the virus dropped quickly in those who were vaccinated, which may reduce the ability to spread illness.

There is emerging evidence that even though cycle threshold values may be the same regardless of vaccination status, people who are vaccinated may have less infectious virus in their bodies, potentially reducing transmission. Richterman pointed to a recent pre-print from China that found a large reduction in transmission in those who had received two doses of vaccine, compared to the unvaccinated.

Vaccines have the ability to prevent transmission of the virus in two ways, he said. The first is by preventing infection altogether. The other is by reducing the amount of infectious virus should somebody get sick.

“People who have been vaccinated will have immune systems at the ready that can coat the virus in antibodies much more quickly than unvaccinated people who have to build up an immune response,” Richterman said.

The new study showed that protection against transmission seemed to wane over time, however. After three months, people who had breakthrough infections after being vaccinated with AstraZeneca were just as likely to spread the delta variant as the unvaccinated. While protection against transmission decreased in people who had received the Pfizer vaccine, there was still a benefit when compared with people who were unvaccinated.

Since antibody levels also tend to decrease over time after vaccination, a reduction in protection against transmission is to be expected, Richterman said.

“We know that the amount of antibodies circulating in the blood decreases over time after vaccination, even though the immune memory remains durably robust and is still able to prevent infections, particularly severe infection,” he said. “These circulating antibodies that are immediately available probably play some role in preventing transmission if infected, so I don’t think it’s surprising to see some reduced protection against transmission over time.”

Richterman and Butler-Wu agreed that while community transmission remains high, masks and testing remain important.

“We need to combine our vaccines with other measures to reduce how much virus we get exposed to by things like masking and testing,” Butler-Wu said. “Additive measures is the name of the game here.”

Richterman agreed.

“While there may be a level of vaccination coverage high enough where other interventions like masking and distancing aren’t needed, we certainly aren’t there yet in many parts of the U.S.," he said.

https://www.nbcnews.com/health/health-news/vaccinated-people-are-less-likely-spread-covid-new-research-finds-n1280583

 

 

 

 

 

 

[gummy]

Well there will be many now working overtime to dispel all elements of truth in that research.

[Lawyers_Guns_and_Money]

In addition to the benefit of a lower viral load, people who have chosen to be vaccinated are also more likely to continue to take preventative measures. They are more likely to continue social distancing when necessary, wearing a mask appropriately when required, and in general practice healthy habits. My observation is that most people that are anti vax and anti mask, are those people that would struggle if they get covid. 

[Changnam43]

Well that is good news.

Watch out.  Lunacy incoming in 5..4..3..2..1..

[9S_]

https://mobile.twitter.com/ANTHONYBLOGAN/status/1444390327884947461?ref_src=twsrc^tfw|twcamp^tweetembed|twterm^1444390327884947461|twgr^|twcon^s1_&ref_url=https%3A%2F%2Fwww.zerohedge.com%2Fmarkets%2Fvaccinated-individuals-can-spread-covid-almost-easily-after-90-days-walensky-warns-over
 

 

[BlueSphinx]

11 minutes ago, 9S_ said:

https://mobile.twitter.com/ANTHONYBLOGAN/status/1444390327884947461?ref_src=twsrc^tfw|twcamp^tweetembed|twterm^1444390327884947461|twgr^|twcon^s1_&ref_url=https%3A%2F%2Fwww.zerohedge.com%2Fmarkets%2Fvaccinated-individuals-can-spread-covid-almost-easily-after-90-days-walensky-warns-over
 

Instead of the link you posted, I embedded the Twitter video-message with that Rochelle Walensky message.

 

[BlueSphinx]

1 hour ago, MrStretch said:

Vaccinated people are less likely to spread Covid, new research finds

British scientists examined how the Pfizer-BioNTech and the AstraZeneca vaccines affected the spread of the virus if a person had a breakthrough infection.

Oct. 2, 2021, 3:39 AM +07      By Akshay Syal, MD

https://www.nbcnews.com/health/health-news/vaccinated-people-are-less-likely-spread-covid-new-research-finds-n1280583

The discussion based on that INCORRECT article did take place already 2 days ago.  I am not going to redo it here, as it can be accessed here >  

 

[9S_]

18 minutes ago, BlueSphinx said:

Instead of the link you posted, I embedded the Twitter video-message with that Rochelle Walensky message.

How you do that? It used to do it for me before now it’s just the link blacked out. I thought twatter was censoring the video

 

And you’re right! She even warned that the vaccinated can infect the unvaccinated! So you have to continue wearing a mask and social distancing!

[BlueSphinx]

44 minutes ago, 9S_ said:

How you do that? It used to do it for me before now it’s just the link blacked out. I thought twatter was censoring the video

> Did sent you a PM on how I did it, but it is always a bit of trial-and-error when embedding Twitter-clips.

[TheDirtyDurian]

59 minutes ago, BlueSphinx said:

The discussion based on that INCORRECT article did take place already 2 days ago.  I am not going to redo it here, as it can be accessed here >  

Just because you say it's incorrect doesn't make it so.

[Rookiescot]

Yeah but some guy on the internet no-one had ever heard of before covid came along said the vaccines dont work.

I just dont know who to believe. Experts say one thing and some random guy says the opposite.

Tis a head scratcher for sure.  

[gummy]

3 minutes ago, Rookiescot said:

Yeah but some guy on the internet no-one had ever heard of before covid came along said the vaccines dont work.

I just dont know who to believe. Experts say one thing and some random guy says the opposite.

Tis a head scratcher for sure.  

They said much the same about AIDS when it was first diagnosed but I wasn't prepared to go "that way" just to prove them wrong 

[Rain]

11 hours ago, Lawyers_Guns_and_Money said:

In addition to the benefit of a lower viral load, people who have chosen to be vaccinated are also more likely to continue to take preventative measures. They are more likely to continue social distancing when necessary, wearing a mask appropriately when required, and in general practice healthy habits. My observation is that most people that are anti vax and anti mask, are those people that would struggle if they get covid. 

Yes, more than likely this is truer than not. 

[BraveNewFahrenheit]

Pfizer fanboys, you probably don't want to watch this...straight up corporate evil, shocker I know!

 

 

[billywillyjones]

2 hours ago, BraveNewFahrenheit said:

Pfizer fanboys, you probably don't want to watch this...straight up corporate evil, shocker I know!

Very interesting let's see if the peanut gallery responds or runs and hides from this information.

[ExpatPattaya]

2 hours ago, BraveNewFahrenheit said:

Pfizer fanboys, you probably don't want to watch this...straight up corporate evil, shocker I know!

Wow, if these are Pfizer scientists, I have little hope for the future.  Uhhh probably, or like, probably,  Like the RNA only attaches to one virus and ....you probably have more anti-bodies if you got Covid.  Forgot to say if you got Covid and lived...  555

[JackIsAGoodBoy]

In other words the COVID vaccines are leaky and that is the worst nightmare for vaccine developers. That is because it creates an additional mutation pressure pathway for virus to overcome the vaccine protection eventually. Even worse, the virus via mutations could become more lethal in the process because of that artificial pressure imposed. 

Then there is also the danger of ADE, meaning the vaccine with binding of a virus to suboptimal antibodies enhances its entry into host cells. In other words, if that happens you are more screwed than without the vaccine against the virus.

Edited October 5, 2021 by JackIsAGoodBoy