Friday, December 25, 2020

Rolling Out the Vaccine

 This morning’s New York Times offers a panel discussion on the question of who should get vaccinated against Covid first.  Broadly speaking, they take a utilitarian position: it’s interesting that none disagreed with the positions taken by panelist Peter Singer, the world’s most prominent utilitarian philosopher.  And I wouldn’t either, except for one thing.

The vaccines approved by the FDA, along with those approved by other countries like China and Russia, have gone through the fastest possible testing.  Tens of thousands of individuals have been placed in control and treatment groups in order to determine two things: to what extent do the vaccines reduce the likelihood of getting infected (efficiency) and how common and severe are the side effects (safety)?  Meeting both criteria is sufficient for approval, which is how it should be.

But there is another crucial question, to what extent do the vaccines reduce transmission of the virus to others?  The answer does not affect whether these vaccines should be employed, but they do have large consequences for other policies during this phase of the pandemic, such as rules for separation and masking, restrictions on activities and events, resumption of in-person schooling, and how much should be spent on interventions like ventilation overhauls. To the extent that vaccination reduces transmission, other restrictions and investments can be modified as the vaccinated portion of the population increases.  Unfortunately, our knowledge of this issue is minimal.  We don’t have any published lab results at all, and we are at least months away from meaningful epidemiological data.

A rollout that prioritizes crucial learning could change this.  Some substantial portion of the early vaccines could be reserved for community trials.  A number of communities could be given treatments in which a designated proportion of the population is vaccinated as soon as possible; this portion could be varied (30%, 50%, 70%) so that a variety of treatments could be tested.  Others matched to them by relevant demographic, economic and other variables would be controls and would not receive any vaccines during the trial period.  (Note that the lack of blinding at the community level should not be a serious problem as long as unvaccinated individuals in treatment communities are given a convincing placebo.)   Everyone living in these communities would be tested regularly.  We could then observe differences between community infection rates corresponding to treatment and infer transmission probabilities under real world conditions.  It might also be possible to learn how transmission varies across the different viral strains that have emerged.  The entire operation could be accomplished within the space of a month or less.

What is disheartening is that not a single expert on the Times panel broached this possibility.  They are entirely preoccupied with the health significance of vaccination at the individual level and consider communities only in social and economic terms.  To the extent they consider the need for learning at all it is in the context of individual response to vaccines, such as comorbidities and interactions with other drugs people may be taking.

Where’s the public health?


Kaleberg said...

How are you going to define community so that one gets useful data? One thing we've learned from COVID is that people have surprisingly broad interpersonal networks.

Peter Dorman said...

You're right that I passed over a lot of implementation issues, such as nailing down the unit of observation/analysis and sample selection. If we were serious about doing the job right, we'd have a team of research design specialists on it. I think GPS travel data would be important both for planning and data collection, and perhaps this would help address your question. Obviously, it's not necessary to have a closed system, just a sufficiently dense one and an ability to detect the extent to which the infected population has more external (out of community) exposure.

In general, I think it should be clear that a fully experimental rollout is not feasible, but a semi-experimental one is.

Fred C. Dobbs said...

‘The Pandemic Is a Prisoner’s Dilemma Game’

NY Times - December 20

Madhur Anand, an ecologist, and her husband, Chris Bauch, a mathematical biologist, were optimally situated during the spring lockdown, working from home in Guelph, Ontario, to watch the pandemic play out — and to discuss patterns of behavior, within their community and beyond, as we all tried to keep safe and carry on.

Their offices at home are separated only by a wall, rather than a 45-minute drive. Dr. Anand is the director of the new Guelph Institute for Environmental Research at the University of Guelph, and Dr. Bauch runs a lab at the University of Waterloo. The couple’s collaborative research usually focuses on the interplay between human behavior and environment systems — for instance, with pollution, deforestation and climate change. Whereas those dynamics unfold slowly, the pandemic provided an acute example of rapid change.

“Societal change is not the kind of thing you can easily experiment with,” Dr. Anand said. “But here we were in the middle of a huge social experiment.”

Like many scientists, they redirected their research to Covid-19. The resulting study, led by their doctoral student Peter Jentsch and currently under peer review, looked at vaccination prioritization: To save the most lives, who should get the vaccine first?

As infectious disease studies go, their methodology was somewhat atypical because it applied game theory, a mathematical way of modeling how people make strategic decisions within a group. Each individual has choices, but the payoff for each choice depends on choices made by others. This is what’s called a “prisoner’s dilemma game” — players weigh cooperation against betrayal, often producing a less than optimal outcome for the common good.

The pandemic presents an everyday complexity of such choices. Imagine, Dr. Bauch said, if everyone followed public health recommendations: They wore masks, socially distanced, washed their hands, followed stay-at-home orders. “In that case there is a significantly reduced risk of infection,” he said.

But there are always trade-offs and temptations to defect from the regimen. Masks are annoying. Hand-washing is tedious. You need a hug.

“The pandemic is a prisoner’s dilemma game played out repeatedly,” Dr. Bauch said. In lectures, he invokes a comparison between Ayn Rand, who made a virtue of selfishness, and the “Star Trek” character Spock, who said, “The needs of the many outweigh the needs of the few.” ...

Fred C. Dobbs said...

More Americans are receiving Covid-19 vaccinations. Many endure chaos to get them

NY Times - January 3

A crashed phone network in Houston. People waiting overnight in long lines in Florida. Older Tennesseans leaning on their walkers outside in the cold alongside a highway.

As distribution of Covid-19 vaccines begins to open up to wider segments of the United States population, there have been scenes of chaos across the country.

The initial vaccine deliveries were mostly for frontline medical workers and nursing home staff members and residents. But there was less of a clear consensus on how to distribute the second round of doses, and public health and elected officials had warned the process would become messier.

Those warnings appear to have been borne out, leaving the U.S. inoculation campaign behind schedule and raising fears about how quickly the country will be able to tame the epidemic.

In Puerto Rico, a shipment of vaccines did not arrive until the workers who would have administered them had left for the Christmas holiday. In California, where coronavirus cases are surging and hospitals are overstretched, doctors are worried about whether there will be enough staff members to both administer vaccines and tend to Covid-19 patients.

Many vaccination sites have operated smoothly since the first U.S. inoculation on Dec. 14, but as availability of vaccines broadened, logistical complications arose at some sites and yielded unnerving images.

In Tullahoma, Tenn., older people lined a sidewalk on Saturday as they waited to enter the Coffee County Health Department’s Tullahoma clinic, about 70 miles northwest of Chattanooga. Most of the people in line were wearing heavy coats or huddled under blankets.

A video of the scene posted to Facebook showed seniors leaning on walkers and canes and sitting on footstools and lawn chairs as they waited for the building to open. Vickie Rayfield Ham, who posted the video, wrote that she thought the distribution center would be a drive-through.

“Some of the elderly were having to walk down the road with their walkers to get to the end of the line, and people were flying by,” she told WTVC, a local television news station.

In a Facebook post that went up shortly before 10 a.m. local time, a couple of hours after Ms. Ham’s video, the city of Tullahoma said that all available doses had been administered for the day and that information about next week’s vaccination schedule would be released on Monday. ...

Fred C. Dobbs said...

The opening day for Houston’s first free public Covid-19 vaccination clinic unleashed so much demand that the city health department’s phone system crashed, causing officials to scramble to move to on-site registration.

Vaccinations began in Houston soon after the first doses of the Pfizer vaccine started arriving at its hospitals on Dec. 14. On Saturday, the city opened a clinic at the Bayou City Event Center providing the Moderna vaccine to high-risk members of the public, saying it could accommodate 750 appointments a day.

Mayor Sylvester Turner said that the health department had received more than 250,000 calls.

“The system was literally overwhelmed,” he said during a news briefing on Saturday.

The clinic’s phone system was back up by the afternoon and as of 2 p.m. local time about 450 people had received a Covid-19 vaccine, Mr. Turner said.

Vaccine rollout sites in Florida continued to be overwhelmed in some places, with people waiting for hours overnight in hopes of getting the shot. The state had expanded its offering of vaccines to older members of the general public — in some cases, on a first-come, first-served basis.

Florida became one of the first states to open up vaccination to anyone older than 65, after Gov. Ron DeSantis issued an executive order on Dec. 23.

Mina Bobel, 74, and her husband, Dave Bobel, lined up at 2 a.m. outside the Lakes Regional Library in Fort Myers, Fla., on Wednesday in hopes of getting vaccinated. They came prepared with snacks and water, and even took turns sleeping in the back of their S.U.V. There were about 300 people ahead of them in line, Ms. Bobel said, and most of them had come well equipped, too — with coats and blankets to keep warm.

“For us, it was an adventure,” Ms. Bobel said, adding that she was “giddy” when finally, around 10 a.m., she stepped up to get her first dose. “We feel really lucky.”

When she left, Ms. Bobel said, the line was even longer than when she arrived.

Fred C. Dobbs said...

More than 4.2 Million People in the U.S. Have Gotten a Covid-19 Vaccine

NY Times - January 2

More than 4.2 million people in the United States have received a dose of a Covid-19 vaccine, according to the Centers for Disease Control and Prevention, far short of the goal federal officials set to give at least 20 million people their first shots before the end of December.

The federal government said Saturday that it had delivered more than 13 million doses to states, territories and federal agencies. The shipments, which came after a record-setting race to develop, study and approve a vaccine, have marked a turning point in the pandemic at a time when deaths and cases continue to set records.

But federal health officials recently acknowledged that the vaccine rollout had had a slower-than-expected start and said they did not have a clear understanding as to why only a small portion of the doses shipped across the nation had made it into arms. ...