美国传统基金会-新冠病毒突破性感染和死亡的统计分析（英）-2021.8-18页_444kb

Summary of "A Statistical Analysis of COVID-19 Breakthrough Infections and Deaths"

Core Content

This document presents a critical statistical analysis of the CDC's recent guidelines and reports regarding the effectiveness of COVID-19 vaccines, particularly against the Delta variant. The authors argue that the CDC's new recommendations, which suggest that vaccinated individuals should wear masks in public indoor settings, are based on flawed or misleading data. They emphasize that the data do not support the claim that vaccines offer little protection against the Delta variant, and that the CDC's approach risks increasing vaccine hesitancy.

Main Points

• Vaccine Efficacy: The vaccines from Pfizer, Moderna, and Johnson & Johnson have provided significant protection against serious illness and death, including from the Delta variant.
• CDC Guidelines: The CDC updated its guidelines for fully vaccinated individuals, recommending mask-wearing in public indoor settings in areas of high transmission. This recommendation is criticized as being unsupported by the data it claims to rely on.
• Barnstable County Outbreak: The CDC's new report is based on an outbreak in Barnstable County, Massachusetts, where 469 cases were linked to public events. However, the data from this outbreak are not representative of the general population and are insufficient to draw conclusions about vaccine effectiveness.
• Breakthrough Infections: Of the over 164 million fully vaccinated Americans, only 7,525 were hospitalized or died from COVID-19, representing a very small percentage (0.005%).
• Positivity Rates: The authors calculated the positivity rates for vaccinated and unvaccinated attendees at the Barnstable events, showing that the rate for vaccinated individuals was significantly lower than for unvaccinated ones.
• Misleading Headlines: Headlines that suggest a high number of breakthrough cases among vaccinated individuals are misleading and do not account for the actual vaccination rate of attendees.
• Comparative Risk: The document compares the risk of death from COVID-19 for the vaccinated to other causes of death, showing that the risk is much lower than that of heart disease, cancer, or other common causes.
• Policy Recommendations: The authors recommend that government officials focus on promoting vaccination rather than imposing mask mandates on the vaccinated, and that they present data accurately and responsibly.

Key Information

• Total U.S. Cases and Deaths: Over 35 million Americans have been infected with COVID-19, and more than 600,000 have died.
• Vaccination Rates: As of August 4, 2021, over 164 million Americans were fully vaccinated, and 191 million had partial immunity.
• Delta Variant Prevalence: The Delta variant was responsible for over 80% of new U.S. cases by the end of July 2021.
• Breakthrough Cases: The CDC reported 7,101 hospitalizations and 1,507 deaths among fully vaccinated individuals, with 26% and 21% of these cases being asymptomatic or not related to the virus.
• Barnstable Event Positivity Rates: Based on assumptions, the positivity rate for vaccinated attendees was 1.21%, while for unvaccinated attendees it was 4.67%.
• CDC Report Flaws: The CDC's report on the Barnstable outbreak is not a controlled study and fails to provide sufficient context or analysis to support its conclusions.
• Mask Effectiveness: The CDC's new guidelines imply that masks are more effective than vaccines in preventing infection, but this is not supported by the available evidence.
• Public Health Confusion: The CDC's conflicting messages have led to public confusion and may have contributed to increased vaccine hesitancy.

Charts and Tables

• Chart 1: Shows the daily new cases and deaths in the U.S. over the course of the pandemic, highlighting a significant decline after vaccine rollout.
• Chart 2: Depicts the number of daily vaccine doses administered in the U.S., showing a steady decline after April 2021.
• Table 1: Provides calculated positivity rates for vaccinated and unvaccinated attendees at the Barnstable events, based on different vaccination rates.
• Chart 3: Illustrates the potential positivity rates for the Barnstable events, showing that breakthrough cases among the vaccinated are very rare.
• Chart 4: Compares the odds of dying from various causes, including heart disease, cancer, and other common causes, to the odds of dying from a breakthrough case of COVID-19.
• Chart 5: Compares the survival rates of different age groups from influenza and COVID-19, showing that the elderly have lower survival rates from both diseases, but the difference is less pronounced for influenza.

Conclusion

The document concludes that while the CDC's new guidelines may appear to suggest that vaccines are less effective, the underlying data do not support this claim. Instead, the data show that vaccines provide substantial protection against serious illness and death. The authors call for a more accurate and responsible use of data in public health messaging to avoid unnecessary fear and to encourage vaccination.