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.

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.