Writings

Old narratives can take a long time to die. This is especially true in the field of health and nutrition. Here, science moves at an astonishing rate, uncovering new evidence and data,  often overturning outdated thinking. But “homespun wisdom” is as stubborn as it is unscientific, and it sadly continues to muddy the waters of debate.A recent article speaking to the dangers of Palm Oil follows the old trope that remains pervasive despite being disproven by evidence.

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Without doubt, the Covid-19 pandemic requires urgent action: to protect the vulnerable from severe disease and death; to prevent the overwhelming of the health-care system; and to keep businesses, schools, and ordinary life humming. But the sense of panic infusing traditional and social media outlets as they report on the pandemic is out of all proportion to the reality of the situation

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As we get closer to full approval of one or more of the promising candidates for a Covid vaccine, it’s becoming clear that we will not quickly have an adequate supply to vaccinate the entire adult U.S. population, and that many will forego this first round of vaccination. As such, it’s unlikely that an emergency vaccine will allow us to stop the spread of infection through herd immunity.

An effective vaccine can still fit into a broader transmission-control strategy, however. A few months back, I wrote that it’s “reasonable to conclude that we may see continued outbreaks for more than one to two years,” and that the U.S. needs to learn how to coexist with the virus. Even a moderately effective vaccine of limited availability and acceptance can significantly improve our ability to do this.

In the next six to eight weeks, the FDA is likely to review an interim analysis of the results of one or more of the Phase 3 trials underway. Many assume that this review will result in FDA approval of vaccine for emergency use; full approval will most likely come in the first quarter of 2021, after six months of follow up.

If emergency use of the vaccine is granted, the highest risk and most vulnerable individuals will be among the first vaccinated. While it’s not yet clear exactly who will fall into these categories, they will likely include health-care personnel, first-line emergency responders, those with chronic disease, and the elderly. (With luck, they will also include those living in communities hit hardest by the virus.) But even if only elderly people receive the first round of vaccinations, it will significantly change the risk-benefit equation for controlling the spread of Covid.

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Early in the COVID pandemic, there was much discussion of super-spreaders — a single individual attending a routine and harmless event such as a birthday party, church service, or dinner party who caused many other people to become infected. As the pandemic has evolved and started significantly infecting young adults, we have become more focused on mass-gathering places such as bars and beaches.

Both super-spreaders and places for mass gatherings share something in common: multiple individuals coming into contact with multiple other individuals in a relatively short period of time. This type of mixing pattern is termed “concurrency” and has been used to explain how many infectious diseases such as HIV spread through a community. A correlate of this model is that in settings where individuals have high levels of concurrency, there is the opportunity for them to infect more than one person, causing exponential growth in the infection (e.g., an outbreak). In contrast, without concurrency, one person may not infect anyone else and the spread slows.

However, concurrency alone does not lead to continued transmission or outbreaks of COVID. Other factors need to be present. Public-health and government officials need to take the combination of factors beyond concurrency into account when making recommendations about events and settings. If one dives deep into the White House’s plan for the phased reopening of the country and watches the current policy reactions of government officials to the emerging hotspot, the influence of this multifactorial perspective on the growth in COVID infections is apparent.

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As the world waits for a safe and effective Covid-19 vaccine, government and public-health officials have continued to focus on the importance of personal behaviors such as social distancing, facial coverings, and testing as the best means to contain the spread of the infection and reduce the number of deaths. Much less public attention has been directed toward the strategic value of Covid testing. Discussions about testing have focused, understandably, on more narrow issues such as test availability and wait times for results. What’s missing is a broader discussion of how testing could be the mainstay of a strategy for controlling spread of the disease that could lead to resumption of normal social and commercial life.

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FDA approval of a Covid-19 vaccine will be only the start of a necessary series of events that should ultimately lead to individual-level protection, herd immunity, and a decline in transmission of infection. When most people develop immunity—either from previous infection or vaccination—it’s less likely that an infected individual will encounter someone susceptible to the virus. Thus, widespread immunity would reduce the likelihood of transmission. And so, by slowing the spread of infection, widespread vaccination leads to herd immunity.

Herd immunity protects those not yet immunized or infected, those whom the FDA decides should not get the vaccine, and those who develop only partial immunity from the vaccine. Therefore, herd immunity is essential to eliminating Covid-19 and reducing deaths due to infection. And, in turn, widespread acceptance of the vaccine is essential for herd immunity.

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All across the country a significantly higher percentage of diagnosed COVID-19 cases, hospitalizations, and deaths are occurring among African Americans (Black, Non-Hispanics) than would be expected based on the percentage of African American in the US. These disparities extend to Black, Hispanics. The findings of national case surveillance data and CDC’s national surveillance of COVID-19 hospitalizations provide support for these regional patterns.

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Today, July 20, New York City starts Phase 4 of the reopening of its commercial and social institutions, approximately 15 weeks after the peak of the outbreak there—and several weeks after all other areas in the state crossed this milestone.

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The recent increase in COVID case numbers is very concerning, but limited in what it tells us about the nature of the current spread of COVID.

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Over the past several weeks, with the lifting of stay-at-home orders across the country, we have seen a day-over-day increase in the number of new Covid-19 cases reported in several states. Some observers are sounding the alarm that another public-health crisis looms. Implicit to this message is the need to return to a more restrictive mitigation policy.

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