The Centers for Disease Control and Prevention (CDC) has finally released the data that was behind its recent backtrack on mask recommendations for vaccinated Americans to wear masks in indoor places in COVID-19 hot spots.
In a report published on Friday, the federal health agency detailed a COVID-19 outbreak earlier this month in Barnstable County, Massachusetts, linked to the spread of the Indian ‘Delta’ variant.
Researchers found nearly three-quarters of the infections occurred in people who were fully vaccinated against COVID-19 with either of three shots approved in the U.S. for emergency use.
What’s more, tests showed that immunized people carried about the same viral levels in their noses and throats as unvaccinated people did.
However, there were just four hospitalizations and no fatalities among the fully vaccinated group, showing that the vaccines are very effective against severe disease and death.
A new CDC report detailed 469 cases of COVID-19 linked to an outbreak in Provincetown, Massachusetts between July 3 and July 17, of which 74% were in fully vaccinated people
Only four of the vaccinated people were hospitalized, two of whom had underlying conditions, and there were no deaths showing vaccines are effective even against the Delta variant, which now makes up 83% of all new infections
For the report, the team looked at COVID-19 cases linked to summer events and large gatherings in Provincetown, on Massachusetts’s Cape Cod, between July 3 and July 17.
Thousands of residents and tourists flocked to the summer town for Independence Day celebrations as well as family vacations, resulting in crowded bars, restaurants, rental homes and more.
On July 10, the Massachusetts Department of Public Health began receiving reports of an increased number of cases linked to the county.
The 14-day rolling average of COVID-19 cases in the county rose from zero cases per 100,000 persons on July 3 to 177 cases per 100,000 persons.
By July 26, 469 cases had been identified, of which 74 percent – or 346 – were among fully vaccinated with at least 14 days since their final dose.
Among this group, 46 percent had received the Pfizer-BioNTech vaccine, 38 percent got the Moderna vaccine and 16 percent got the Johnson & Johnson vaccine.
The remaining 26 percent, or 84 cases, were among people who were unvaccinated, had only received one dose or whose vaccination status was unknown.
Results showed that vaccinated people who get COVID-19 have same viral levels as the unvaccinated
Nearly 80 percent of those with ‘breakthrough’ infections had signs or symptoms such as cough, fever or a headache.
Of the five COVID-19 patients who were hospitalized, four were fully vaccinated of whom two had underlying conditions.
No deaths were reported in either group.
This is evidence that the Pfizer, Moderna and J&J vaccines are highly effective against severe disease and death.
To measure levels of the virus, CDC researchers looked at a figure known as the cycle threshold (Ct) value.
After an infected person is swabbed, the sample is isolated and has to undergo several amplification cycles to detect if there is any viral RNA, or genetic material.
The Ct value is the number of cycles necessary to spot the virus at which point the machine will stop running. Any number under 30 is considered a high viral load.
There was virtually no difference in the Ct value between vaccinated and unvaccinated people.
Fully vaccinated patients has a Ct value of 22.77 while the unvaccinated group had a Ct value of 21.54.
Ideally, the number among vaccinated people should be higher than 35 and closer to 40, which would indicate low levels of the virus.
‘High viral loads suggest an increased risk of transmission and raised concern that, unlike with other variants, vaccinated people infected with Delta can transmit the virus,’ CDC director Dr Rochelle Walensky said in a statement.
‘This finding is concerning and was a pivotal discovery leading to CDC’s updated mask recommendation.
‘The masking recommendation was updated to ensure the vaccinated public would not unknowingly transmit virus to others, including their unvaccinated or immunocompromised loved ones.’
The release of the data comes after The Washington Post obtained and published internal documents from the CDC.
The documents claim the Delta variant is as infectious as chickenpox or Ebola and that an infected person can spread the virus to eight or nine other people.
Meanwhile, the original strain that originated in Wuhan, China, could be passed on two or three others, making it as transmissible as the common cold.
The CDC was criticized this week for updating the mask guidance without detailing the science behind it.
‘Yes, CDC should release all data in a timely manner,’ Dr Ali Mokdad, an epidemiologist with the University of Washington’s Institute for Health Metrics and Evaluation, told DailyMail.com on Thursday.
‘In my opinion, it is criminal to sit on data during a pandemic.’