Posted by:
Nightingale
(
)
Date: August 11, 2021 01:04PM
Mayo Clinic re herd immunity, June 2021:
https://www.mayoclinic.org/diseases-conditions/coronavirus/in-depth/herd-immunity-and-coronavirus/art-20486808Excerpts:
“Herd immunity occurs when a large portion of a community (the herd) becomes immune to a disease, making the spread of disease from person to person unlikely. As a result, the whole community becomes protected — not just those who are immune.
“What percentage of a community needs to be immune in order to achieve herd immunity? It varies from disease to disease. The more contagious a disease is, the greater the proportion of the population that needs to be immune to the disease to stop its spread. For example, the measles is a highly contagious illness. It's estimated that 94% of the population must be immune to interrupt the chain of transmission.
“How is herd immunity achieved?
“There are two main paths to herd immunity for COVID-19 — infection and vaccines.”
There are nuances further explained in the article. Each statement above should not be taken in isolation but with an abundance of related information.
NYT article, July 2021:
https://www.nytimes.com/2021/05/03/health/covid-herd-immunity-vaccine.htmlExcerpts:
“Now, more than half of adults in the United States have been inoculated with at least one dose of a vaccine. But daily vaccination rates are slipping, and there is widespread consensus among scientists and public health experts that the herd immunity threshold is not attainable — at least not in the foreseeable future, and perhaps not ever.
“Instead, they are coming to the conclusion that rather than making a long-promised exit, the virus will most likely become a manageable threat that will continue to circulate in the United States for years to come, still causing hospitalizations and deaths but in much smaller numbers.”
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Experts strongly encourage everyone who can be vaccinated to receive their two doses. With a high percentage of vaccinated individuals this helps protect those who can’t be vaccinated.
It’s true that recommendations can change as more information is gleaned from experience as we go along.
CBC article, July 26, 2021:
https://www.cbc.ca/news/canada/ottawa/covid-19-unvaccinated-final-push-herd-immunity-delta-1.6113769Excerpts:
“Like the last leg of a marathon, public health officials say reaching the final segment of the unvaccinated population will be a grind as Ottawa tries to attain herd immunity — when enough of the population is protected against COVID-19.
“The city of Ottawa has set a daunting target to fully vaccinate 90 per cent of its population, including those still not eligible to be vaccinated, which has eluded most regions around the world.
“As of July 23, 73 per cent of the city's entire population had received at least one dose of vaccine, slightly higher than the Ontario rate of 69 per cent, and one of the highest vaccination rates for first doses among cities around the world.
“Ontario's first-shot vaccination rate has dropped from a high of six per cent per week in May to below one per cent in July, and it continues to trend downward. That means it will take longer to inoculate the remaining portion of the unvaccinated population — likely a venture that continues into 2022.
"I think I can't understate how important it is to get very high levels of vaccination," said Dr. Trevor Arnason of Ottawa Public Health.
"If we head into the fall with vaccination where it is now, we're definitely going to see outbreaks."
“Ontario, which has now been in Stage 3 of the reopening plan for 10 days, must reach 80 per cent of its eligible population with at least one dose, and 75 per cent with both doses, to consider removing all public health restrictions.
“Some public health experts believe that target is not high enough due to the growing number of cases of the delta variant and the potential for breakthrough cases.
"We need to establish herd immunity, and we would need to be at a higher level: 85, 90 per cent vaccination rates," explained Dr. Paul Roumeliotis, the medical officer of health for the Eastern Ontario Health Unit, who also heads a group of public health units across Ontario.
“Roumeliotis and Arnason say restrictions could return in the fall if delta spreads, even if they're not as strict as those we've seen throughout the pandemic. Ontario public health officials hope to avoid a spike in cases seen during the reopening in the U.K., Israel, and the United States.”
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We’re still talking about trying to achieve herd immunity in Canada.
Not being able to get there due to low rates of vaccination is different from concluding that herd immunity is not desirable or attainable.
Edited 1 time(s). Last edit at 08/11/2021 01:06PM by Nightingale.