Coronavirus: Gov. Newsom says things will be normal when we have “herd immunity.” Here’s why that’s scary.
What does ‘herd immunity’ look like? About 28 million infected Californians. Maybe 840,000 deaths.
By LISA M. KRIEGER | Bay Area News Group | Mercury News
April 16, 2020 at 7:00 a.m. | UPDATED: April 17, 2020 at 4:36 a.m.
Amid Gov. Gavin Newsom’s scenario of a post-sheltering world, there are two chilling words: herd immunity.
Tomorrow’s tableau — waiters with masks, distant desks, split-shift schools — will be the new normal, he told reporters in his Tuesday press briefing, “at least until we have herd immunity.”
The phrase came up again as he explained what’s ahead, as “we begin to transition into suppression, ultimately, on our way to herd immunity” and a vaccine. He repeated it later, describing progress “towards herd immunity.”
What’s herd immunity? It’s when so many people have been infected and develop protective antibodies that a virus runs out of hosts. That’s likely what happened in the 1918-1919 flu pandemic, which killed 20 million to 40 million people and then vanished.
What does “herd immunity” look like in the age of COVID-19? Without a vaccine, about 28 million infected Californians. Based on current estimates, about 5 percent of infected people — or roughly 1.4 million Californians — would get severely ill. Of these, 840,000 could die, although there’s hope of holding that number down.
This bleak strategy may be the only way through a pandemic that is causing profound economic, social and education paralysis. A vaccine, which also could provide herd immunity, is 12 to 18 months away, with likely additional months needed to scale up manufacturing and distribution.
It’s also very scary. The governor’s promised “light at the end of the tunnel” could instead be the glaring halogens over an ICU bed.
As if in synchrony, on Tuesday scientists at Harvard’s prestigious Harvard T.H. Chan School of Public Health also conceded the inevitability of continued infections.
In a set of mathematical models published in the journal Science, they proposed a strategy of intermittent restrictions that would help us approach herd immunity as slowly as possible, so hospitals aren’t overwhelmed.
Rather than hiding from the virus, a goal is to spread out the number of infections at any one time, so fewer people die, they concluded.
“Several rounds of social distancing will be required to get us to ‘herd immunity’ in the absence of vaccination,” said Harvard epidemiologist and study co-author Dr. Marc Lipsitch.
This is the concept: If a large number of people — the “herd” — are immune, then a vulnerable person in the middle of the herd is unlikely to be exposed. Life goes on.
Based on early estimates of this virus’s infectiousness, we likely will need at least 70% of the population to be immune to have herd protection, according to Johns Hopkins School of Public Health epidemiologists Gypsyamber D’Souza and David Dowdy...
The goal is to infect the most while killing the least. That demands an exquisitely calibrated state strategy: counting each illness, then lifting or imposing very targeted restrictions to create smaller and better-managed outbreaks.
To reach herd immunity, “there’s no light switch here” of all-or-nothing restrictions, said Newsom. “It’s more like a dimmer … toggling back and forth.”
Full story at https://www.mercurynews.com/2020/04/16/coronavirus-gov-newsom-says-things-will-be-normal-when-we-have-herd-immunity-heres-why-thats-scary/The governor's news conference referred to above is at:
or direct to https://archive.org/details/newsom41420
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