April 05, 2021

Covid Cathy Bites the Dust

Now that just under half of older people have been fully vaccinated against Covid-19 and only about a quarter have not received any vaccinations at all,  the burning question is, what can vaccinated people do safely? 


The answer comes in two parts: what can vaccinated people do that does not jeopardize their own health and what can they do without risking harming others? The CDC has weighed in on this, focusing principally on the first issue, safety of the individual. Their guidance includes the recommendations that those who are fully immunized (who are at least two weeks out from their second shot) can visit other fully immunized people indoors without masking or social distancing and that they can travel without self-quarantining upon arriving at or returning from their destination.


To answer the second question, the public health concern, we need to know whether a vaccinated individual can be infected with Covid-19, remain asymptomatic, and transmit the disease to an unvaccinated person. Physicians have been concerned that while the antibody response to vaccination is highly effective in squelching the virus in the lungs, what’s not clear is whether it’s also effective in killing the SARS-Cov2 virus in the nasal passages. If so, vaccinated individuals could indeed be surreptitious sources of disease, like the notorious Mary Mallon, who was an asymptomatic carrier of the bacteria causing typhoid fever, salmonella typhi. Could asymptomatic Covid carriers act like “Typhoid Mary,” perhaps earning the nickname Covid Cathy? At last, we have very reassuring data addressing this issue.


The current issue of MMWR, the weekly journal published by the CDC, reports on the experience of just under 4000 people during the period mid-December and mid-March, 2479 of whom received two shots of either the Pfizer or Moderna vaccines and 989 controls who remained unvaccinated. They also report on 477 people who received one dose, but for simplicity, I will ignore these partially immunized individuals. The investigators leading this small study took one crucial step that has previously been largely lacking: they tested all the participants weekly using the gold standard polymerase chain reaction (PCR) test for the SARS-Cov2 virus—whether or not they had been vaccinated and whether or not they reported symptoms. What did they find?


The outcomes are reported based on “person-days” since the group who were vaccinated got their shots at varying times and therefore differed in the number of days they could have become infected. They found that among the fully immunized, the number of new positive tests/1000-person-days was 0.04 whereas among the unvaccinated, it was 1.38. The bottom line: once you are fully immunized, you are far less likely to test positive for Covid-19 than if you have received no vaccinations.


The study also found that only 23 percent of the people who did develop an infection got sick enough to see a physician, only two people were hospitalized, and no one died. 


Until this admittedly small but carefully conducted study appeared, it seemed to me that while vaccinated people could feel personally quite safe, they had to exercise caution in the interest of public health. It wasn’t really true that vaccinated people could socialize indoors with other vaccinated people—until the issue of Covid Cathy was resolved, they had to be worried about about any unvaccinated household contacts their friends might have, lest an asymptomatic carrier inadvertently transmit the virus to a friend, who while also asymptomatic, manages to give the virus to an unvaccinated household member. Now it increasingly looks as though this theoretical concern is not, in practice, of great consequence. 


Just because fully vaccinated individuals are reasonably safe today doesn’t mean they will necessarily remain safe tomorrow. Vaccine effectiveness is calculated based on how much less likely a vaccinated person is to get the disease than an unvaccinated one. But if the disease is running rampant in the surrounding community, that is, if it is quite common among the unvaccinated, then while the relative risk of the vaccinated will be unchanged, the absolute risk will go up. And if new variants appear against which the vaccines offer only limited protection, then the relative risk itself will be affected. 


So, keep an ear to the ground—monitor how common the virus is in the community where you live and pay attention to the type and pervasiveness of viral variants. If the situation is stable, enjoy your freedom.

March 04, 2021

How I Taught My 95-Year-Old Mother to Make and Receive Video Calls--Most of the Time

My 95-year-old mother has been using a computer for email since our then teenage son arranged to gift her his old computer so he could get a new one. That was 25 years ago. But like most people in her age cohort, she has never been comfortable with the technology and has trouble learning anything new related to the computer. The difficulty has gotten worse over time along with her memory. But when Covid hit and visits to the independent living complex where she lives were restricted and then eliminated, the limitations of a landline telephone became all too evident. If my mother could make and/or receive video calls, she could communicate with me, with her three grandsons in California, and with friends. But using the video technology proved to be an endless source of frustration. We tried FaceTime, we tried Skype, we tried Zoom. Nothing worked. 

Now, after months of trial and error and refining the approach, I’m pleased to report that my mother can receive—and sometimes initiate—FaceTime calls. I’m so pleased that I’m going to use this blog post to describe in as much detail as I can recall every step necessary to accomplish this feat, suspecting as I do that others may find themselves in a similar predicament.

                                                Happy geriatric iPad user 
                                                (not my mother)

Step 1: Choose an appropriate device. I purchased my mother a new 10.2 inch, 32GB iPad. It’s portable, so she can use it while sitting in her favorite recliner. The screen is big enough so that people’s faces appear almost life-size and photographs are easy to see. In principle, Apple products are user-friendly, though as it turned out, my mother is a genius at outwitting the human-computer interface gurus at Apple by coming up with ways to make the system fail. Nonetheless, I think the iPad was probably as good a choice as any and better than some. The rest of the steps below apply primarily to an iPad.

Step 2: Obtain a cover that automatically turns the device off when it is closed and turns the device on when it is opened. Turning the iPad on manually was an unnecessary obstacle.

Step 3: Disable password protection for turning the device on. This may be a bit risky, but my mother was having trouble remembering her password. I “enrolled” her in touch ID, but she usually managed to put her finger in not quite the right place, so it did not work reliably. Nothing is more frustrating than being unable to even turn the thing on.

Step 4: Go to Settings, Accessibility, Assistive Touch. This setting allows my mother to use the iPad even though she has poor fine motor control and touches the screen erratically.

Step 5: Label the home button. I stuck an arrow on either side of the home button to help my mother find it. The device is designed with a very slight indentation signaling the home button, so slight that it’s hard for 95-year-old eyes to see. ➡️ ⏺ ⬅️

Step 6: Make sure Siri is disabled. I initially thought it would be easiest if my mother used Siri to make calls, simply saying “hey Siri, call Muriel Facetime video.” Wrong. She would leave out “FaceTime” or leave out “video” or forget to start with “hey Siri.” She felt compelled to speak in grammatically correct sentences, as though Siri would understand her better that way. When I left Siri enabled, just in case things changed, I found that my mother would sometimes hold the home button down too long and inadvertently invoke Siri, who would helpfully inquire “may I help you?” Having her device suddenly speak really rattled my mother.

Step 7: Put only the most essential icons in the dock. For my mother, this includes the icon for her email, Safari, and for FaceTime video. I’ve recently added the photos icon.

Step 8: Declutter the screen by putting as many of the obligatory icons, the ones you can’t get rid of, on the next screen, not the screen that is opened when the device turns on.

Step 9: Put the handful of phone numbers (with associated names) that are most likely to be used in the FaceTime contacts screen. This way, when my mother taps on the video icon, she will see 4 or 5 names and can choose which one she wants to call. Sometimes she taps on the wrong spot and calls the wrong person, but at least she’s not accidentally going to call Social Security or the Boston Globe, just a different family member from the person she intended.

Step 10: Practice! When visiting my mother, I would get her settled in her recliner with the iPad and call her from another room. For a while she had trouble with the command “slide to answer.” I finally figured out that she was carefully sliding her finger along the words “slide to answer” and assiduously avoiding the green virtual button to the left of the words. Unless she accidentally touched the button, she failed to answer the call. Now I regularly remind her that she needs to slide the button and it works like a charm. Another aspect of practicing is using the system regularly. At one point, my mother was doing great and then we didn’t make any video calls for a few days, by which time she had forgotten about sliding the button rather than the words. Making or receiving a call once a day is probably a good idea.

Sounds simple, doesn’t it? Since it literally took me months to figure this out, I thought I’d pass along what I learned, in case these steps can help someone else.



February 26, 2021

Pfizer in Practice

This week brought a medical article worth discussing: the New England Journal of Medicine published the results of a study of the efficacy of the Pfizer SARS-CoV-2 vaccine in the real world. The article provides compelling evidence that the vaccine works extremely well.

The data come from Israel, which has been doing a superior job of vaccinating its citizens. As of a week ago, two-thirds of the currently eligible population in Israel had gotten both of the recommended doses (individuals under age 16 and those who have had Covid-19 are not eligible). In Israel, health insurance is mandatory for all permanent residents; they must join one of four healthcare organizations called “funds.” The new study reports data from Israel’s largest health organization (Clalit Health Services) and includes information on a stunning 1.2 million people.

The study’s authors, led by Dr. Noa Dagan, used Clalit's integrated electronic medical record to capture health data for 596,618 people who received both doses of the Pfizer vaccine between December 20, 2020 and February 1, 2021. They then matched them, based on demographic and clinical characteristics, with another group of identical size who had not received any vaccine. Next, they looked at five different outcomes: documented Covid-19 infection; symptomatic Covid-19 infection, Covid-related hospitalization, Covid-related severe illness, and Covid-related deaths. Because the sample was so large, they were also able to collect extensive information about a number of interesting subgroups defined by age or specific co-existing health conditions such as cancer or diabetes.

The article includes an enormous amount of intriguing data. The most exciting results, from my perspective, address outcomes a week or more after receiving the second dose of the vaccine. At that point, the vaccine conferred 94% protection against symptomatic Covid-19 (95 percent confidence interval 87-98), 87 percent protection against Covid-related hospitalization (CI 55-100), and 92 percent protection against severe Covid (CI 70-100).  The efficacy in people over 70 was identical to those in younger individuals, and the rate in people with one chronic health condition such as diabetes was only slightly lower than in people without the condition. 

These numbers strongly resemble the results that Pfizer and BioNTech reported to the FDA in their application for emergency approval.  But, as the study authors point out, Pfizer drew its conclusions based on 44,000 people; the Israeli study is based on 1.2 million people. As a result, when Pfizer calculated the efficacy against severe Covid-19, they drew on a total of 10 cases (one of whom had been vaccinated and 9 of whom had not been); when the Israelis calculated the risk of severe Covid, their estimate was based on 229 cases, vastly increasing the credibility and certainty of the calculation. Moreover, Pfizer’s data was based on the somewhat artificial conditions of a clinical trial: for example, the subjects were all highly motivated to optimize their health and may have regularly worn masks and practiced social distancing; the Israeli study drew on real life experience, in which participants’ behavior reflected community norms.

The new study, like all studies, has its limitations. It excluded people living in nursing homes and medical personnel working on Covid units in the country’s hospitals, arguing that the rate of the disease in their particular communities, i.e. the nursing home or the Covid ward, was highly atypical. The study was performed during a period when the South African variant was very rare in Israel so we cannot draw conclusions about the efficacy of the vaccine against this strain. The information on the ability of the vaccine to prevent Covid-related deaths is limited because of the short follow-up period: there were nine Covid deaths in the fully vaccinated and 32 deaths in the unvaccinated group, but these numbers might change when more time elapses. The data on deaths may also be difficult to generalize as Israel has an unusually low case fatality ratio: in Israel, according to Johns Hopkins' "Our World in Data," is currently 0.7 percent whereas in the U.S. it is 1.8 percent.

Some of the study’s greatest strengths are also potential weaknesses: the “real world” nature of the investigation means it is an observational study rather than a randomized controlled trial, raising the possibility that the differences in outcomes between the vaccinated and the unvaccinated were related to some factor other than their vaccination status. Despite these limitations, the study provides very encouraging information.

The fact that the Israelis could carry out their study sends another message over and beyond the efficacy of the Pfizer BioNTech vaccine. The study could only be conducted because Israel did a good job acquiring and distributing vaccine. Early on, the country developed mass vaccination sites. Since everyone is enrolled in a health plan and the plans all have electronic records, there was no need to waste as much time on bureaucracy as we do in the U.S, where more time is spent filling out forms than on administering the shot. The study could only be conducted because of Israel’s electronic health records, which assured that information about who got what dose when, and the age, sex, and chronic medical conditions of each individual was digitally recorded. Finally, the entire rollout was centrally coordinated, assuring efficiency and consistency: from the outset of the pandemic, the Israeli Ministry of Health collected Covid-related data from all four health plans, negotiated to purchase vaccine from Pfizer, and organized distribution. The good news reported in the NEJM article is a result both of the biological properties of an mRNA vaccine that was designed in record time to deal with an international health crisis of enormous proportions, and of the characteristics of a health care delivery system that can actually deliver.

February 21, 2021

The Next Big One

              As new cases of Covid-19 fall throughout the world but the US approaches 500,000 deaths from Covid-19 and the world nears 2.5 million deaths, it is time to start planning for the next pandemic. 

               We have known since the 1918 influenza pandemic, which killed upwards of 50 million people world-wide, that it’s not a question of if, but rather of when. Moreover, recent decades have seen the emergence of several new and terrifying diseases. These diseases have principally been caused by viruses, viruses that jumped species. They moved from their usual host, say a civet or a bat, into people for one of several reasons: climate change may have destroyed their hosts’ usual habitat, forcing them to find a new home where they came into greater contact with humans; alternatively, humans encroached on the hosts’ habitat by clearing forest or planting a crop that deprived the host of its usual food source, again leading the host to relocate; or humans may have developed a taste for certain types of wild animal, bringing the two species into unaccustomed contact and thus facilitating viral transmission.

              As a result of these factors, we have had Zika, SARS, MERS, avian influenza and now Covid-19 in the twenty-first century, and Ebola, Marburg hemorrhagic fever, and HIV in the last part of the twentieth century. These are only the best-known of “zoonoses.” Today, 75 percent of new infectious diseases are zoonotic in origin and their numbers have been rising steadily. 

            The good news is that we know a great deal about how to go about preventing outbreaks, detecting them early, and responding if they nonetheless occur. The bad news is that the world in general and the U.S. in particular have a poor track record of implementing the necessary strategies. Allocating scarce resources now to help alleviate problems that will develop at some unspecified time in the future has proved to be a hard sell. 

                The irony is that we in the U.S., as in many other countries, spend an enormous amount of money on our military. We have accepted the need to devote a large fraction of our budget to the armed forces and to equipment including both “conventional” and nuclear weapons. We have not yet acknowledged that the far greater threat to our national security and our well-being is from lowly viruses, strange biological entities that are not strictly speaking alive since they cannot survive outside a host organism, not from invading armies. 

            The current US budget consists of just under $3 trillion on “mandatory spending,” which includes Social Security, Medicare, and Medicaid; and another nearly $1.5 trillion on “discretionary spending,” over half of which is for military spending, including the VA and Homeland Security as well as the armed forces. The base budget for the Department of Defense is $636 billion.

             By comparison, the CDC (Centers for Disease Control), the site for most of the U.S. epidemic preparedness activities, has a total budget of $6.6 billion, of which $509 million is allocated to “Emerging and Zoonotic Infectious Diseases.” Other disaster preparedness activities are financed through various departments, including Homeland Security, which is part of the military. But as a very rough approximation, it is not far-fetched to say that the core budget for potential epidemics is $509 million compared to the core budget for the military of $636 billion, or .08 percent.  This comparison reveals an enormous imbalance between spending on the military and on epidemic preparedness, with too much to fight armed invasions and not nearly enough to combat microbial enemies.

            If we are to spend more on epidemics—and, arguably, less on bombs and fighter planes—what should we spend it on? A basic framework was outlined at a symposium called “Building Interdisciplinary Bridges to Health in a Globalized World,” organized by the Wildlife Conservation Society in 2004. The symposium called for an international, interdisciplinary approach to preventing disease, or “One Health, One World.” It articulated its views in a document called the Manhattan Principles which laid the foundation for what would become an international movement. The Manhattan Principles is built on  the recognition that modern epidemics stem from the inter-connections between humans, domestic animals, and wildlife, and that these interactions arise either directly from human behavior (eg agricultural practices, clear cutting forests, and eating wildlife), or indirectly, mediated by climate change that is in turn due to human behavior. Since the problem is fundamentally multidisciplinary, its solution must likewise be multidisciplinary. And since the modern world is interconnected, the solution must be international, involving sharing information.

            An implementation framework was drawn up in 2008 by a group consisting of representatives from UNICEF, WHO, the World Bank among others. Entitled “A Strategic Framework for Reducing Risks of Infectious Diseases at the Animal-Human-Ecosystems Interface,” it argued for the development of an international system of disease surveillance drawing on multidisciplinary expertise (to include veterinarians, physicians, wildlife specialists, and ecologists). In addition, it sought to help build robust public health systems across the globe and to promote good communication between those systems. Finally, it advocated support for strategic research, to be shared internationally. 

            The One Health approach was adopted by the CDC in 2009, which housed it within its National Center for Emerging and Zoonotic Infectious Diseases. It was formally endorsed by the UN, the World Bank, and the EU in 2010. More recently, the World Bank came up with a revised operational framework to fight EIDS as a means of fulfilling its mission to promote prosperity and decrease poverty.

            Our response to future epidemics, when they occur, will hinge on more than international and multidisciplinary collaboration. Scientific developments are likely to have a major impact when future EIDs arise. The new technique of vaccine design using mRNA is vastly accelerating the development of effective vaccines, the most powerful preventive tool available. Work on anti-viral medications is ongoing and could revolutionize treatment of viral diseases much as antibiotics revolutionized the treatment of bacterial diseases. Currently, the only virus for which there is effective treatment is HIV, and that treatment (which took years to develop) involves a multi-drug regimen that converts HIV into a chronic disease but rarely eradicating the infection. 

            We also need to strengthen the public health infrastructure in the U.S. Poor coordination, insufficient manpower, and inadequate communication to the public have afflicted domestic public health departments for years. WHO and the World Bank have focused on shoring up public health in much of the world but assumed that the richest countries would serve as models of success. 

            The One World framework could itself be expanded to address climate and the environment more expansively, but the basic formulation is sound. As Andrew Cunningham, Peter Daszak, and James Wood argue in their 2017 article, “One Health: Emerging Infectious Diseases and Wildlife: Two Decades of Progress?” little has been done at the policy level to address what remain major threats to health and well-being, as Covid-19 attests. It’s time to adjust our national priorities and focus on what counts. 



January 11, 2021

The Home Stretch

For Americans over age 65, the Covid-19 vaccine really is coming soon. States have varying policies on prioritizing distribution of the vaccine, with some states already giving it to those older than 65 and others planning to get to the over 75 group very soon and the 65-74-year-olds shortly thereafter. In all cases, the expectation is that by April, all older Americans will have had the opportunity to be vaccinated. 

If you are reading this post, you have made it this far—so my message today is don’t blow it now by throwing caution to the winds. The virus is striking more people each day than ever before, and despite the progress in treatment, more people are hospitalized and more people are dying than at any time in the past year. 

The US also has the dubious distinction of being number one in the world in terms of cumulative mortality from Covid-19.  

Tired as we all are of masks and social distancing and of just plain staying home, these are the only strategies we have until we are vaccinated—and even then, we’ll need to wait until most of the population has been vaccinated before we can relax. A more infectious strain, isolated in the UK, is here in the US. It may be far more widespread than we know since public health officials are not routinely testing for it. Just because we haven’t found it doesn’t mean it doesn’t exist: it just means we’re not looking for it. 

The implication of all this is that it would be prudent not merely to remain careful, but to increase your vigilance. Writing in the medical news periodical, STAT, several physicians and an engineer argue that we should wear high filtration masks such as the N-95. We should take their proposal seriously. While N-95 masks are primarily restricted to health care workers, KN-95 masks, which are in many cases equivalent, are available from Amazon, some local pharmacies, and a variety of other on-line sources. Most of these have not been tested for effectiveness or reliability by American government regulators, but many have been subjecting to assessment by one or more international agencies. The CDC has made available a list of many KN95 masks and the results of the assessments. 

My recommendation is to start wearing one of the KN-95 masks on this list, choosing one that has a minimum filtration efficiency of at least 95 percent. Wear it indoors in any public space. Do not socialize indoors except with members of your household. Do not take unnecessary risks and don’t let down your guard! 

January 01, 2021

Looking Forward

            Once the 1918-1919 influenza pandemic finally came to an end—after killing somewhere between 50 and 100 million people worldwide—Americans did their best to forget about it. Later tragedies such as AIDS and 9/11 figured prominently in much American fiction, but influenza was seemingly forgotten by American writers: Katherine Anne Porter’s short story, “Pale Horse, Pale Rider” and William Maxwell’s novella, “They Came Like Swallows,” are rare exceptions. Historians and journalists writing about the 1918 flu have hypothesized that the pain and suffering inflicted by the flu paled by comparison with that attributable to World War I, which came to an end at the same time, even though ten times more Americans died of the flu than died in combat. Or perhaps Americans were so optimistic about scientific medicine, which was just coming into its own in the twentieth century, that they chose to ignore medicine’s great failure, its inability to diagnose, treat, prevent, or cure influenza. Maybe Americans simply repressed this traumatic episode that killed people in the prime of life, leaving families without a means of support and children without a mother or father. Will the Covid-19 pandemic similarly be forgotten, or will it have a profound and enduring effect on us as individuals and on us as a society?

            The pundits are already speculating about the long-lasting effects of the pandemic on the real estate market and on the work place, on professional conferences and the movie industry. But what I would like to address is the life lessons we should take away from this devastating and unexpected year. The first is that our lives are tenuous. We in the developed world have come to expect a long healthy life, especially if we are white and middle class. Life expectancy at birth in the US is just under 79 years; if you make it to age 65, you can expect to live another 20 years. Covid-19 showed us that we should not take those years for granted: while 80 percent of the Covid deaths have been in people aged 65 or older, that means that 20 percent have been in people under 65. As of the end of December, 2020, 346,000 Americans had died from the disease, which translates to 69,000 younger people. There’s nothing like awareness of our own mortality to concentrate the mind and encourage us to live life well and to the fullest. This is the first lesson and the one we are perhaps most likely to forget.

            The second lesson is that what matters most to us as human beings is our relationships with other people. That’s what made “social distancing” so painful; it’s why eliminating family visits to nursing homes was so devastating; it’s why Zoom, FaceTime, and other video chat programs have been such a lifesaver. We need to cultivate our friendships, to nourish them, to work to improve them. The pandemic made us believe that other people are the enemy, which runs counter to our essence as social creatures.

            The third lesson that I want to emphasize is of a different sort: it is that to make decisions about most anything important and certainly to make medical decisions, we need to understand something about risk. How to behave during the epidemic was all about how to evaluate risk, how to think about risk. Just because most people who don’t wear masks and who go to group gatherings won’t get sick doesn’t mean that these are safe activities. It means that you markedly increase the chance that you will contract the virus if you go around without a mask or attend a group meeting. And understanding risk is more complicated still: how much you increase your risk depends on how widespread the virus is in the surrounding community. If very few people in the vicinity of where you live are sick, then your likelihood of getting the disease is low, even if you fail to take precautions. But as the virus begins to circulate more widely, then precisely the same behavior pattern that was only slightly unsafe before will become far more dangerous. 

            Understanding risk is tricky because the epidemiological measures designed to protect individuals, whether wearing a mask, practicing social distancing, or getting vaccinated, are not perfectly effective. Some people who wear a mask will nonetheless contract the virus; ditto for people who stay six feet away from others. Individuals who received either the Pfizer or Moderna vaccination in the clinical trials were one-twentieth as likely to get sick as those who received a placebo. But that means that just how safe you can feel if you are vaccinated  (even if the effectiveness holds up in a much larger population than was tested in the trials) also depends on how widespread the virus is: while vaccination lowers your relative risk of getting sick, if the number of infectious people in the community suddenly increases, say by a factor of ten, your chance of getting the disease also goes up by a factor of ten, even if you've been vaccinated. Grasping the concept of risk is essential—not just to dealing with an infectious disease, but also to deciding whether to undergo screening for prostate cancer, whether to take medication for borderline high blood pressure, and whether to invest in the stock market. 

           Americans, along with people across most of the globe, have lost much from our encounter with the corona virus. We have also gained something: an appreciation for life’s fragility, a recognition of the importance of relationships, and a deeper understanding of risk. It is up to us to remember, both those we have lost and what we have learned.