Critical New Data From CDC on Delta Variant: Vaccinated People May Spread Disease
Friday, July 30, 2021
An internal presentation made late on Thursday at the Centers for Disease Control was obtained by The Washington Post. The presentation contains important new information with profound implications for managing the COVID-19 pandemic in the U.S.
The information in this document informed the CDC’s decision this week to revise their guidance to recommend that everyone, even the vaccinated, return to wearing masks indoors.
GET THE LATEST BREAKING NEWS HERE -- SIGN UP FOR GOLOCAL FREE DAILY EBLASTThe document contains references to a number of yet unpublished data and studies. Overall, the CDC presentation confirms the Delta variant is different from prior strains. It is more transmissible, causes more serious disease, and is partially resistant to vaccines. Perhaps the most overwhelming observation in the presentation is that breakthrough infections may be as transmissible by vaccinated as unvaccinated people.
As a measure of how much more contagious the Delta variant is, each person infected with Delta infects an average of 5 to 9 other people, compared with 1.5 to 3.5 for the original SARS-CoV-2 strain. The Delta variant is as transmissible as chickenpox, and in comparison, is more contagious than Ebola, the common cold, the flu, and smallpox.
Recent clinical results from Israel report the Pfizer vaccine to still be strongly effective in protecting against hospitalization (88%) and severe illness (91%) from the Delta variant, but only 39% effective in preventing infection and 41% effective in protecting against symptomatic illness. These results suggest that even vaccinated people could have a more than 50/50 chance of becoming ill if infected by the Delta variant.
However, the CDC presentation reaffirms the great importance of vaccination in battling the pandemic. Vaccination reduces the risk of disease 8-fold compared with being unvaccinated, and reduces the risk of hospitalization or death 25-fold.
Vaccine breakthrough cases are expected and will increase as a proportion of total cases as vaccine coverage increases. In May, 9% of hospitalized COVID patients and 15% of in-hospital COVID deaths were among vaccinated patients, compared with essentially zero in January.
The most astonishing finding with profound ramifications is the observation that vaccinated individuals appear to carry as high of a viral load as the unvaccinated, and may be just as contagious. This observation was based on an analysis of 145 COVID cases in Barnstable County Massachusetts, which found no differences in viral load between vaccinated and unvaccinated individuals.
These data are noted as preliminary and subject to change. However, if reaffirmed, these observations have significant impacts on the future of the pandemic and what must be done to successfully combat it. If vaccinated and unvaccinated individuals carry similar viral loads and are comparably contagious, then the current vaccines alone will not be able to end the crisis or allow life to return to normal. The CDC presentation acknowledges this and calls for additional, non-vaccine measures.
“Non-pharmaceutical interventions are essential to prevent continued spread with current vaccine coverage – cannot rely exclusively on vaccines.”
Vaccines can prevent more than 90% of severe disease, but are less effective against the Delta variant at preventing infection or transmission. Therefore, we are experiencing more breakthrough infections and more community spread despite vaccination.
The latest CDC findings have particular importance for us. Rhode Island is experiencing very rapid growth in new COVID cases, currently the 9th fastest in the U.S. Rhode Island’s infection rate is now 1.44 and rising. This means each infected person infects on average 1.44 other people. This is exponential growth, and has reached “Critical” risk. This measure is important because it predicts the future. Extrapolating this growth rate leads Rhode Island to an even higher level of infection than we are already experiencing. It calls for swift, decisive, prudent safety measures to be implemented immediately, before cases once again reach catastrophic levels. At this rate, we may well once again attain the notorious distinction of being one of the most highly infected places on the planet. If we want to avoid that calamity, the time to act is now.
The CDC presentation urges vaccine mandates for health care providers to protect vulnerable populations, universal masking for control and prevention of infection, and importantly, other community mitigation strategies.
“Given higher transmissibility and current vaccine coverage, universal masking is essential to reduce transmission of the Delta variant.”
Yesterday Pfizer released data showing that a third (booster) dose of its vaccine can increase antibody levels 5-fold in those aged 18-55, and 11-fold in those 65-85. Pfizer estimates a 100-fold increase in Delta neutralization after a third, booster dose of vaccine.
At the same time, Thursday Israel announced it will be offering booster shots to anyone over age 60.
Critical Importance of Vaccination
The CDC report and these new findings do not in any way diminish the tremendous importance of the vaccines.
Rather, they reflect the scientific process of learning from new information. Everything that is known about COVID has been discovered just within the past 18 months. Less than two years ago, it was completely unknown. A tremendous amount has been learned in a very short time, which is testimony to the heroic efforts and massive efforts by scientists around the world. However, there is still a great deal that we don’t know. Moreover, the SARS-CoV-2 virus is evolving and changing rapidly. The Delta variant is a game-changer, and in many ways, a different disease than the one we faced last year. The basic process of scientific research is to learn as much and as quickly as possible and then adapt to new information. The world will continue to learn about COVID, and must adjust to new evidence and change direction as needed – this is the only way we will prevail against such a novel and formidable biological threat.
Nick Landekic is a retired scientist and biotechnology executive with over 35 years of experience in the pharmaceutical industry.
Related Articles
- Rise of the Delta Variant Calls for Re-Doubling Efforts to Overcome Vaccine Hesitancy - Horowitz
- In Rhode Island, How Survivable Is the Delta Variant for the Unvaccinated?
- Is Rhode Island Ready for the Delta Variant?
- Delta Variant Has Hit RI – What You Need to Know
- Gov. Baker Announces 2 New Mass Vaccination Sites
- Deep Concerns Emerging of Variants “We’re Playing Whac-a-Mole” - GoLocal Daily RI Vaccination Update
- Biden Admin’s Pharmacy Distribution Plan Undercuts RI Priorities - GoLocal Daily Vaccination Update
- New Details on RI’s Vaccination Clinics, Continued Poor Rate - GoLocal Daily Vaccination Update
- Lt. Gov. McKee: “I’m Not Satisfied With Current Administration’s Progress” on Vaccinations
- RI Ranks Among the Worst for Vaccine Utilization - GoLocal Daily RI Vaccination Update
- More Frustration Directed at RIDOH’s Vaccination Program - GoLocal Daily RI Vaccination Update
- GoLocal Daily RI Vaccination Update: CVS to Be in Eye of Vaccination Storm
- GoLocal Daily RI Vaccination Update: NYT Flags RI As Only State Not to Expand Eligibility
- Rhode Island’s Vaccination Sign Up Website Goes Live
- Community Provider Network of RI on Vaccination Site for People with Disabilities — LIVE
- Reps. Fenton-Fung and Casimiro Urge RIDOH to Offer Vaccinations to Caregivers of Chemo Patients
- AARP RI Challenges Raimondo, McKee, Shekarchi and Ruggerio to “End Vaccination Chaos”
- Biden: All Americans to be Eligible for Vaccinations by May 1, Cookouts by July 4th
- McKee Announces Plan to Get COVID-19 Vaccinations to All RI Teachers, School Staff by End of Month
- 5 Major Developments in Vaccination Program
- Rhode Island Has a New Vaccination Problem — Not Enough Are Signing Up
- Delta Variant May Impact RI’s Pandemic Recovery, Vaccination “Cold Zones” May Fuel Spread
- Luxury Apartment Tenants Get Prioritized in Providence for Early Vaccination
- McKee Pledges to Prioritize RI Teachers for Vaccinations; Teachers Union Applauds Move
- Raimondo Under Attack From All Directions for Failed Vaccination Program
- Raimondo Administration Defends Vaccination Strategy, But Numbers Don’t Add Up
- McKee’s Vaccination Plan, Too Many Bosses and NEA’s Walsh Says Raimondo’s in Conflict with Biden
- EDITORIAL: RI’s Economic Recovery Is Being Sabotaged by Incompetent and Arrogant Vaccination Program
- 50 Top Healthcare Groups Call for Mandating Vaccination of Healthcare Workers
