Anthony S. Fauci, MD returns to JAMA’s Q&A series to discuss the latest developments in the COVID-19 pandemic, including the continued importance of nonpharmaceutical interventions (masking, handwashing, physical distancing) for managing rising case numbers in the US and globally.
Recorded October 28, 2020.
Topics discussed in this interview: 0:00 Introduction 0:20 NAM Presidential Citation for Exemplary Leadership 1:19 COVID-19 numbers and excess deaths 4:05 National masking mandate 5:55 How to get people to accept masking 7:07 Herd Immunity and the Great Barrington Declaration 9:51 The holidays and airplane travel 13:44 Therapies update 17:54 Vaccines update 20:08 Vaccine distribution 22:00 Vaccine safety 24:42 How Australia has dealt with COVID-19 spikes 27:00 Acknowledgements and baseball
Herd immunity occurs when a significant portion of a population becomes immune to an infectious disease, limiting further disease spread.
Disease spread occurs when some proportion of a population is susceptible to the disease. Herd immunity occurs when a significant portion of a population becomes immune to an infectious disease and the risk of spread from person to person decreases; those who are not immune are indirectly protected because ongoing disease spread is very small.
The proportion of a population who must be immune to achieve herd immunity varies by disease. For example, a disease that is very contagious, such as measles, requires more than 95% of the population to be immune to stop sustained disease transmission and achieve herd immunity.
How Is Herd Immunity Achieved?
Herd immunity may be achieved either through infection and recovery or by vaccination. Vaccination creates immunity without having to contract a disease. Herd immunity also protects those who are unable to be vaccinated, such as newborns and immunocompromised people, because the disease spread within the population is very limited. Communities with lower vaccine coverage may have outbreaks of vaccine-preventable diseases because the proportion of people who are vaccinated is below the necessary herd immunity threshold. In addition, the protection offered by vaccines may wane over time, requiring repeat vaccination.
Achieving herd immunity through infection relies on enough people being infected with the disease and recovering from it, during which they develop antibodies against future infection. In some situations, even if a large proportion of adults have developed immunity after prior infection, the disease may still circulate among children. In addition, antibodies from a prior infection may only provide protection for a limited duration.
People who do not have immunity to a disease may still contract an infectious disease and have severe consequences of that disease even when herd immunity is very high. Herd immunity reduces the risk of getting a disease but does not prevent it for nonimmune people.
Herd Immunity and COVID-19
There is no effective vaccine against coronavirus disease 2019 (COVID-19) yet, although several are currently in development. It is not yet known if having this disease confers immunity to future infection, and if so, for how long. A large proportion of people would likely need to be infected and recover to achieve herd immunity; however, this situation could overwhelm the health care system and lead to many deaths and complications. To prevent disease transmission, keep distance between yourself and others, wash your hands often with soap and water or sanitizer that contains at least 60% alcohol, and wear a face covering in public spaces where it is difficult to avoid close contact with others.
The US Surgeon General’s office has released a report emphasizing the importance of making hypertension control a national public health priority. Vice Admiral Jerome Adams, MD, MPH, the 20th US Surgeon General, discusses the report’s background and recommendations.
2020 American Diabetes Association (ADA) guidelines recommend that after a trial of metformin, doctors add additional drugs based on the presence of cardiovascular and kidney-related comorbidities, risk of weight gain and hypoglycemia, and cost. In this video, Irl B. Hirsch, MD, of the University of Washington in Seattle, explains the rationale for starting insulin next for patients with persistent HbA1c elevation above 9-9.5% despite lifestyle changes and metformin.
Even limited hearing loss might be associated with cognitive decline. If true, early intervention with hearing aids might help people have better cognitive performance.
Michael Johns III, MD, online editor for JAMA Otolaryngology, speaks with Justin Golub, MD, MS, assistant professor of otolaryngology at Columbia University, whose research has shown that very mild hearing loss can be associated with cognitive disability.
Food and medicine shopping is essential during the COVID-19 pandemic, but requires getting out and standing close to strangers at a time when social distancing and sheltering-in-place are recommended to slow spread of disease.
David Aronoff, MD, director of the Division of Infectious Diseases at Vanderbilt University in Nashville, explains how to minimize COVID-19 risk while shopping.
Nathan Pritikin was a college dropout who became an entrepreneur. While doing research for the government during World War II, he observed that populations that had extremely limited food availability because of the war had substantially reduced mortality from cardiovascular disease—something unexpected at a time when cardiovascular disease was thought to be due to stress.
After the war when food became more available CVD death rates went back up, resulting in Pritikin concluding that CVD was related to diet. Pritikin devised his own very low-fat diet that bears his name and the diet is still in use 65 years later.
Drug Pricing Theme Issue: Is Pharma Earning Too Much?, R&D Costs Required to Bring a New Drug to Market, Probiotic Safety, and more
One in 4 people in the US has difficulty paying the cost of their prescription medications. This stark fact was recently reported in a 2019 Kaiser Family Foundation public opinion poll among a nationally representative random sample of 1205 adults.1 Persons who reported having the greatest difficulty affording their prescription drugs were those who most needed them, including those who took 4 or more prescription drugs, spent $100 or more per month on their drugs, and reported being in fair or poor health.