Top scientists today claimed the Indian ‘Delta’ variant is not spreading as quickly as chickenpox, despite US health officials saying it is just as contagious.
Data circulating within America’s Centers for Disease Control and Prevention (CDC) claimed people infected with the mutant strain can go on to infect eight others.
The same internal document also alleged that fully-vaccinated people can spread the Indian variant just as easily as unvaccinated people because they carry a similar amount of the virus in their nose and mouth.
Dr Rochelle Walensky, the director of the CDC, insisted the agency was ‘not crying wolf’, saying the situation was ‘serious’ and that the measures needed to tackle the spread of Delta were ‘extreme’.
But British scientists have questioned some of the claims made by the department, which has urged Americans to keep their coverings on indoors regardless of whether they’ve been vaccinated or not.
Professor David Livermore, an infectious diseases expert from the University of East Anglia, said vaccine-triggered immunity and the endless waves of Covid which nations have endured meant there were fewer susceptible people around for people to infect.
‘The US, like the UK, has substantial immunity from prior infection and from vaccination,’ he told MailOnline. ‘This will surely be a major drag on Delta’s spread, precluding (viral spread) numbers of that magnitude.’
And Professor Julian Tang, a virologist at Leicester University, said the theory was likely just ‘speculation’ because it was very difficult to track down the number of cases sparked by a single infection.
This graph shows how many people someone infected with the above diseases is likely to transfer them on to. For people who catch chickenpox, scientists estimate they will pass on the infection to between 10 and 12 others. And for those who catch measles, they are thought to pass it on to 12 to 18 others. Scientists at the CDC have estimated every person who catches the Indian ‘Delta’ variant of Covid could pass it on to eight other people. But British scientists say this is not correct
Dr Rochelle Walensky, the director of the CDC, said the agency was ‘not crying wolf’ over the ‘serious’ situation. But British scientist Professor David Livermore said it was not plausible that the Delta variant was being passed to eight others for every person it infected. He said if this was the case then the UK’s cases would not be dipping
The R0 — the basic reproduction rate which shows just how contagious every disease is — of Delta is thought to be around eight, the CDC says.
That means, in theory, anyone infected with the mutant strain — which is now dominant in dozens of countries — will pass it on to eight others.
What does the CDC claim in its latest report?
Leaked slides from a presentation by the US-based Center for Disease Control and Prevention have made several claims about the Indian ‘Delta’ variant of Covid.
Its director, Dr Rochelle Walensky, said they highlighted how ‘serious’ the situation had become.
Below, MailOnline has gone through the key claims.
Indian ‘Delta’ variant of Covid is as infectious as chickenpox
The R0 — the basic reproduction rate which shows just how contagious every disease is — of Delta is thought to be around eight, the CDC says.
That means, in theory, anyone infected with the mutant strain — which is now dominant in dozens of countries — will pass it on to eight others.
For comparison, the original strain of Covid that triggered the pandemic in the Chinese city of Wuhan had a figure of around 2.5. The Kent ‘Alpha’ variant’s rate is around 4.5.
But measles — which is one of the most contagious viruses known to exist — has an R0 of approximately 18, and the estimate for chickenpox sits between 10 and 12.
This does not mean, however, that everyone infected with Delta is actually passing the virus on to eight others.
The actual R rate — which reflects how quickly an outbreak is growing or shrinking — is always much lower than R0.
This is because it takes into account real-world data which can easily skew the shape of disease outbreaks, such as population immunity.
Infected vaccinated people may pass on the virus ‘as well’ as un-vaccinated people
The CDC also claimed in its internal presentation that vaccinated people may pass on the virus just as well as those who are not jabbed.
It based the claim on a study looking into how much of the virus is carried by infected jabbed and non-jabbed people.
This is called the viral load and it is tested using the Ct value, the number of times a swab for SARS-CoV-2 must be tweaked before the virus is detected. For this reason, a lower score indicates a higher viral load which suggests someone is more infectious.
The claim was based on an outbreak in Provincetown, Massachusetts, which sparked more than 700 cases.
The outbreak happened after July 4 Independence Day, when looser restrictions again allowed Americans to come together to celebrate the national holiday.
Testing data showed among the 80 double-vaccinated people, their average Ct scores was 21.9.
And among the 65 un-vaccinated people included in the study it was 21.5.
Studies warn Ct values are only approximate, and can vary even if the same swab is tested twice.
But studies say a result above 30 suggests a high amount of the virus in someone’s body, and that someone can only be declared negative if the samples are tweaked 40 times without the virus being detected.
British experts said it was highly unlikely that vaccinated people were as infectious as unvaccinated people.
One said the results may be down to there being fewer vaccinated people in America, giving the virus more opportunities to spread.
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For comparison, the original strain of Covid that triggered the pandemic in the Chinese city of Wuhan had a figure of around 2.5. The Kent ‘Alpha’ variant’s rate is around 4.5.
But measles — which is one of the most contagious viruses known to exist — has an R0 of approximately 18, and the estimate for chickenpox sits between 10 and 12.
This does not mean, however, that everyone infected with Delta is actually passing the virus on to eight others.
The actual R rate — which reflects how quickly an outbreak is growing or shrinking — is always much lower than R0.
This is because it takes into account real-world data which can easily skew the shape of disease outbreaks, such as population immunity.
Professor Livermore said if everyone with Delta was really spreading it to eight others, then Britain’s daily Covid cases would not have dipped.
‘I don’t find it plausible,’ he told MailOnline when asked whether infected patients were truly passing the virus on to so many other people.
‘Were it the case, the rise in the UK wouldn’t have stalled in the way that it has.’
Professor Tang said the R0 value was very hard to work out because it was so difficult to establish exactly how many people an infected person passed the virus on to.
He added, in some cases, the virus may spread to many others by one person because of factors including location, but that in other cases someone may not even pass the virus to anyone.
Professor Tang said: ‘If you have someone infected and handing out leaflets by the door of a department store they may not be a super-spreader themselves but just passing it on.
‘But if you stand them near a fan you may find there is an R of 20.’
The CDC’s claim is partially based on an outbreak in Provincetown, Massachusetts, which sparked more than 700 cases.
Leaked slides published by the Washington Post said it happened after July 4 Independence Day, when looser restrictions again allowed Americans to come together to celebrate the national holiday.
Covid finds it easier to spread when people are packed together inside, such as for celebrations and events.
The CDC also claimed that vaccinated people may pass on the virus as well as those who are not jabbed at all because they had similar amounts of the virus in their mouths and noses.
The amount of virus an infected person is carrying is calculated as the Ct value, or the number of times testers need to tweak a sample before they detect the virus. For this reason, a lower score indicates a higher viral load, making it more likely someone is infectious.
Among the 80 double-vaccinated people they checked they had to run the cycle 21.9 times on average before Covid was spotted.
And among the 65 un-vaccinated people included in the study the cycle had to be run 21.5 times.
British Government officials warn Ct values are only approximate, and can even vary if the same swab is tested twice meaning it is hard to make firm conclusions from the data.
But the officials said if the virus is detected after less than 30 tweaks of the sample, then it suggests the infected patient is carrying a lot of virus.
Samples are generally tweaked up to 40 times before someone can be said not to be infected with the virus.
Professor Young said it was ‘hard to believe’ vaccinated people would pass on the virus as well because the jabs slash the risk of someone becoming infected.
Professor Young said it was still clearly sensible to wear masks — even if you are double-jabbed — to limit your risk of catching the virus.
‘Face masks are something I think we still need to be doing,’ he said. ‘A small proportion of people who are jabbed are still able to get re-infected, so people should be cautious.’
Although vaccines are not perfect, they have drastically changed the game against the virus.
Jabs currently being deployed in America and Britain slash the risk of death by up to 95 per cent, even against the Delta variant.
But real-world data of roll-outs in countries where the mutant strain is dominant show they are slightly less effective at blocking symptoms of the illness, as well as transmission.
Yet No10’s top scientists have still publicly backed their ability at curbing the spread of the virus.
Sir Patrick Vallance, the UK Government’s chief scientific adviser, said in January: ‘You don’t have vaccines of this efficacy without there being some effect on transmission.’ The latest SAGE modelling given to ministers suggests the vaccines cut the risk of infected people passing it on by around 50 per cent.
Dr Walensky said yesterday the Delta variant was ‘one of the most transmissible viruses we know about’. She drew a comparison between the virus and measles and chickenpox, which are both highly contagious.
She also called for masks to be worn again. ‘The measures we need to get this under control — they’re extreme,’ Dr Walensky said. ‘The measures you need are extreme.’
The CDC said in May that fully vaccinated people no longer needed to wear face coverings because of falling infection rates and the fact jabs significantly cut the risk of being infected.
But they rowed back on this assertion two days ago, urging fully-vaccinated Americans to again wear the masks amid surging cases in the country and concern over the Delta variant.
The CDC report also claimed vaccinated people who are infected with Covid are likely to shed as much Covid as people who have not been jabbed.
Dr Walter Orenstein, who heads the Emory Vaccine Centre in the US, told CNN the report suggests vaccinated and un-vaccinated people have similar viral loads.
He said: ‘The bottom line is, in contrast to the other variants, vaccinated people, even if they don’t get sick, got infected and shed the virus at similar levels to unvaccinated people who got infected.’
But he also pointed to data from the CDC showing vaccines cut the risk of severe disease by 90 per cent, and reduce the risk of death by tenfold.
Professor Ian Jones, a vaccine expert at Reading University, said: ‘The issue in the US is that there is still a large pool of unvaccinated people so any transmission finds them and they suffer the full range of symptoms.
‘Every variant to date has transmitted better, that’s why they succeed in spreading, but none have evaded the immune response completely.
‘Mask wearing and other social measures continue to make sense while there is a susceptible population but the overall message dose not change, increasing vaccine coverage is the way to bring cases down.’
‘Delta’ variant is as infectious as chickenpox or Ebola and infected vaccinated people transmit it as easily as unvaccinated, CDC document claims as agency says data that led to mask U-turn will be released today
By Harriet Alexander for DailyMail.com
Health officials in the United States will on Friday explain the science behind their U-turn on face masks, as Republicans express skepticism over the decision – which appears to have stemmed from research into a July 4 outbreak.
The Centers for Disease Control and Prevention (CDC) on Tuesday announced that they were updating their previous guidance to now recommend that vaccinated people wear face masks once more, when indoors and in parts of the country with substantial COVID-19 transmission.
They did not explain their reason for the shift in policy – which has sparked fevered debate – and merely said it was due to new data on the highly contagious Delta variant. On May 13 the American public was told they no longer needed to wear masks indoors if vaccinated.
An internal federal health document obtained by The Washington Post claimed that the Delta variant was as infectious as chickenpox or Ebola – with each infected person passing the virus to eight or nine others, on average. That infectivity is known as R0.
The original lineage was about as transmissible as the common cold, with each infected person passing it to about two others, on average.
CDC Dr Rochelle Walensky has previously noted the rarity of viruses with such high R values, telling CNN: ‘When you think about diseases that have an R0 of eight or nine — there aren’t that many.’
Officials, the document stated, must ‘acknowledge the war has changed.’
The source of the data was unclear but it appeared to have been provided to the Post and the New York Times at the same time – suggesting the possibility of a coordinated leak.
Dr Rochelle Walensky, the director of the CDC, has said that they will publish the science behind their decision, announced on Tuesday, on Friday. The CDC has faced some criticism for announcing new recommendations on face masks without providing the science behind their decision
The slide presentation said that the CDC must improve its messaging on COVID-19, and emphasize the urgency of the situation.
‘I finished reading it significantly more concerned than when I began,’ said Robert Wachter, chairman of the Department of Medicine at the University of California at San Francisco.
Walensky, director of the CDC, said that the new data – to be published on Friday – showed that vaccinated people infected with the Delta variant carry tremendous amounts of the virus in the nose and throat.
Walensky told The New York Times that the data suggest that even fully immunized people can be unwilling vectors for the virus – a change from the previously-held belief that vaccinated people were unlikely to increase the spread of COVID-19.
Walensky privately briefed members of Congress on Thursday, drawing on much of the material in the slide presentation obtained by The Washington Post.
Walensky is pictured on July 20 testifying before Congress. She briefed Congress on the new scientific findings on Thursday, and on Friday will make the results public
‘I think people need to understand that we’re not crying wolf here. This is serious,’ she told CNN.
One of the slides states that there is a higher risk among older age groups for hospitalization and death relative to younger people, regardless of vaccination status.
Another estimates that there are 35,000 symptomatic infections per week among 162 million vaccinated Americans.
The document outlines ‘communication challenges’ fueled by cases in vaccinated people, including concerns from local health departments about whether coronavirus vaccines remain effective and a ‘public convinced vaccines no longer work/booster doses needed.’
The CDC was criticized this week for updating the mask guidance without detailing the science behind it.
Kathleen Hall Jamieson, director of the Annenberg Public Policy Center at the University of Pennsylvania, told The Washington Post that their move violated scientific norms.
‘You don’t, when you’re a public health official, want to be saying, ‘Trust us, we know, we can’t tell you how,’ Jamieson said.
‘The scientific norm suggests that when you make a statement based on science, you show the science.
‘And the second mistake is they do not appear to be candid about the extent to which breakthroughs are yielding hospitalizations.’
Joe Biden has been strongly urging people to get vaccinated. On May 13 he celebrated the announcement that face masks were no longer necessary – something critics have seized upon
The popular Cape Cod vacation resort of Provincetown is seen on July 24. The artistic and foodie city drew its usual large crowd for the July 4 weekend, with people believing that fully vaccinated people could not transmit the virus. It is now believed that that is not correct
Dressed as Maxine the Vaccine, Poppy Champlin encourages pedestrians to get vaccinated for COVID-19 while promoting her comedy show on Commercial Street in Provincetown, on July 24
Kevin McCarthy, the most senior Republican in the House, claimed the House doctor told them the study was conducted in India using a vaccine that was not approved in the U.S.
‘The mask mandate is based upon a study in India, based upon a vaccine that isn”t approved in America that didn’t pass peer review. Could this be a plan to keep our schools closed?’ he asked on Twitter.
The CDC cites research from India on viral loads as adding to global concerns about transmission post-vaccination, but they make clear that other research and additional studies were under way.
Provincetown: How July 4 weekend turned the partygoing playground of New England into the center of a covid cluster
Located near the northern-most point of Cape Cod, Provincetown – or P-Town – is known for its beaches, artists and as a popular vacation spot for the LGBT+ community.
It has a population of just under 3,000 people year-round, but this raises to as high as 60,000 in the summer months.
Young party-goers descend on the town to make the most of the plethora of bars and clubs found along it’s famous Commercial Street.
Wealthy tourists usually found in nearby cities such a Boston and Manhattan will often use the town as their playground to spend their hard earned cash – or that of their parent’s.
But a week after crowds descended to celebrate the Fourth of July — the holiday President Joe Biden hoped would mark the nation’s liberation from COVID-19 — the manager of the Cape Cod beach town said he was aware of ‘a handful of covid cases among folks who spent time there’
Within weeks, the outbreak rapidly grew until, as of Thursday, 882 people were tied to an outbreak in the town, with 74 per cent of those having had both doses of the vaccine. It was reported that seven people were hospitalised, ABC News reported.
Before this, health officials were assuming that it was rare for a vaccinated person to become infected with the virus and, if they were, they probably wouldn’t infect others.
The assumption was based on studies of an earlier virus, and not the new Delta variant, which was first detected in India earlier this year.
It is indicated that this outbreak is among the new evidence behind the decision to make masks compulsory indoors again, even if they have had both doses of the vaccine.
The owner of Marine Specialties, a long running Army-Navy store, had been leery of officials dropping virus safety mandates ahead of what many expected would be a busy summer season. He even tried to require customers to mask up in his store through the summer, before finally relenting in June.
‘If we’d stuck with masks all along, I don’t think we’d be having this conversation,” Patrick said, adding that he’s required all his staff to be masked and vaccinated. “They’re not entirely fun, but we wore them all last summer, and we didn’t have a single case in Provincetown. Now see where we’re at.’
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McCarthy, however, tweeted a May 13 video of Joe Biden stating: ‘Folks, if you’re fully vaccinated — you no longer need to wear a mask.’
McCarthy captioned the clip: ‘Total hypocrisy.’
Nancy Pelosi, the Speaker of the House, was asked about the backlash to the new mask mandates, and McCarthy’s anger.
‘He’s such a moron,’ she reportedly said, in a scarcely-audible clip.
Yet at the same time, Democratic-run cities have said they cannot make changes without being in full possession of the facts.
Even officials in Democrat areas were unsure.
Mitchell Katz, president of New York City Health and Hospitals, said at a press conference with Mayor Bill de Blasio that he wanted more information.
‘While the CDC issued their guidance yesterday at about 3 p.m., they have not yet released their scientific reports on the data that underlies their recommendation,’ he said.
He added that his focus remained on getting people vaccinated.
‘I think we owe it to New Yorkers to very carefully, as you say, review that information and understand its implications,’ he said.
The CDC experts have been paying particular attention to an outbreak in Provincetown, on Cape Cod, after the July 4 celebrations.
As of Thursday, 882 people were tied to the Provincetown outbreak.
Among those living in Massachusetts, 74 percent of them were fully immunized, ABC News reported, yet officials said the vast majority were also reporting symptoms.
Seven people were reported hospitalized.
The initial findings of the investigation led by the Massachusetts Department of Public Health, in conjunction with the CDC, seemed to have huge implications.
All indications now are that the Provincetown outbreak investigation is among the pieces of new evidence behind the CDC’s decision to ask Americans to once again put on their masks indoors, even if they are vaccinated.
The one glimmer of hope came from Britain, where the Delta variant has wreaked havoc, but is now dramatically slowing down.
Experts hope that this may indicate the U.S. surge could also be over soon.
Last week, the leading British COVID modeler said that the country was ‘almost certain’ to hit 100,000 cases per day, and the U.K.’s daily case count crossed the 50,000 threshold for the first time since January.
Yet since July 20, cases have fallen fast.
From a high of nearly 54,000 on July 17, the daily tally slid to 43,404 last Wednesday; and 28,652 on Sunday.
This Monday, the U.K.’s case count slipped below 25,000 – a 50 percent reduction in a single week.
‘In the United Kingdom, cases are clearly coming down at this point,’ said Dr Scott Gottlieb, the former Food and Drug Administration commissioner, on Monday.
‘If the U.K. is turning the corner, it’s a pretty good indication that maybe we’re further into this than we think, and maybe we’re two or three weeks away from starting to see our own plateau here in the United States.’
The CDC’s sudden U-turn on masks sparked a political firefight on Capitol Hill as Republicans blasted a new mask mandate in the House of Representatives.
Capitol Police backed down on Thursday and said they would ask people in the House not wearing a face mask to leave after Republican lawmakers blasted a memo that stated such individuals would be arrested.
The agency did not specifically rule out arrests, but did say it should never come to that.
‘Regarding the House mask rule, there is no reason it should ever come to someone being arrested. Anyone who does not follow the rule will be asked to wear a mask or leave the premises. The Department’s requirement for officers to wear masks is for their health and safety,’ US Capitol Police tweeted in a statement.
The statement came after it was revealed officers been ordered to arrest visitors and staff who refuse to wear a mask on the House side of the Capitol complex. The policy did not apply to lawmakers who refuse to wear masks.
Conservative Republican lawmakers gathered in the rotunda to march to the Senate side of Capitol, which does not have a face mask policy
Republicans have protested a new policy to wear face masks in the House, refusing to don them
US Capitol Police backed down on a memo that said staff and visitors not wearing face masks in the House would be arrested
Many Republicans have refused to wear masks, citing it as an issue of personal freedom, criticizing the Capitol physician over implementing a mask policy for the House and not the Senate, and arguing the science means vaccinated individuals shouldn’t have to mask up.
Several staffers and visitors were seen walking around the House side of the Capitol without masks on Thursday but were not arrested.
Additionally, several conservative Republicans gathered in the Capitol Rotunda without wearing face masks to protest the policy. ‘Arrest us,’ one shouted as their maskless staff recorded them to post the event to social media.
No one was arrested.
The GOP lawmakers marched to the Senate side of the Capitol, which does not have a face mask requirement. Nearly 100 per cent of the Senate is vaccinated.
Republican Rep. Thomas Massie told reporters they walked across the Capitol building ‘for a taste of freedom.’
‘You don’t have to wear a mask on the Senate side,’ he pointed out.
Many House Republicans blasted Pelosi for the ‘tyrannical’ directive, but the Democrat’s office responded that she ‘does not control the US Capitol Police.’
The chief of the Capitol Police reports to the three-member Capitol Police board, which is made up of the House sergeant at arms, the Senate sergeant at arms and the architect of the Capitol.
The chief does not answer to the speaker. The mask mandate in the House – which requires everyone, including those fully vaccinated, to wear one – was ordered by the Office of the Attending Physician but Pelosi said she would enforce it, which falls under her purview as speaker.
The controversy on Capitol Hill came the same day that Washington, DC Mayor Muriel Bowser announced masks will be required indoors throughout the District, including for those who have been vaccinated against COVID-19.
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