Wednesday, April 22, 2020

Herd Immunity: Only Cure For Wuhan Virus?



What is herd immunity? Alongside reverse quarantine, it can be only cure for Coronavirus: Whether you want it or not, herd immunity through natural course of the virus spread will happen sooner than the onset of same result through universal vaccination.

A lot is being written about herd immunity, even as the death toll from coronavirus infection has crossed 150,000. There is no cheersome update on the early arrival of a vaccine and there is obviously a lockdown fatigue across the world with billions of people straining at the leash.

So, is herd immunity the final, long-term cure for Covid-19? There are arguments on both sides of the question. The supporters say the virus spread will dwindle when a significant portion of humans become immune to it in the natural course. Those who oppose the theory say thousands of vulnerable people will die as the virus travels through and disappears.

However, it appears that whether you want it or not, herd immunity through natural course of the virus spread will happen sooner than the onset of the same result achieved by the universal application of an effective vaccine.

Sweden said on Sunday its refusal to lock down the entire country has succeeded in slowing the virus and that herd immunity is developing. "According to our modelers, we are starting to see so many immune people in the population in Stockholm that it is starting to have an effect on the spread of the infection ... Our models point to some time in May," a top Swedish official told the local media.

Britain's Boris Johnson had pitched the idea earlier, but the government adopted a different line later on. In the US, President Donald Trump had controversially mooted a 'virus wash-over' as a possible outcome.

Those who vouch for the theory say the best road block for the virus is immunity in a critical mass of the population. If it's achieved by vaccination, that's the best outcome, but in the absence of vaccination, the community should get immunity nonetheless.

WHO, as always, is not sure. However, the WHO, as always, is not sure if this works. As of now the WHO can't say for sure if some can contract Covid-19 again, after being cured of it once. The WHO, for that matter, wasn't sure if masks would work, if travel restrictions would work, if CHQ would work and if BCG would work. Now wonder Trump administered a funding therapy to the sleepy body whose best Covid-19 interventions were some inane afterthoughts.

What is herd immunity? In theory, herd immunity stops the virus in its tracks as there are few carriers left for it to move on. This happens in two ways -- when a vaccine makes a vast majority of humans immune against a pathogen and when so many people get the disease and become immune to it in turn.

What do numbers say? According to epidemiologists, in the case of some diseases, herd immunity becomes effective when at least 40 percent of the population develops immunity to a particular pathogen. In other cases, this threshold is between 80 and 95 percent of the population for the immunity to be effective.

Will it work for coronavirus? The early statistics related to the severity of coronavirus infection were more confidence inspiring than the latter day horror stories. It was reported initially that a whole lot of people got cured of the virus without even being diagnosed. And among those diagnosed, a vast majority had only mild symptoms. And in those with serious symptoms, only a tiny percentage died. However, with thousands of more deaths happening daily across the world, herd immunity theory might get fewer buyers.

Will it work alongside reverse quarantine? The one-size-fits-all lockdown will appear to be a safe bet, but it has its risks. For one, the entire humanity remains prisoners of an unseen enemy until a cure or vaccine arrives. That's a statistically impossible scenario but the world is generally plodding along on those lines at the moment. In its place, a 'reverse quarantine' can turn out as a safer option while a herd immunity develops and reaches the desired threshold.

This way, the most vulnerable people including the aged, those with multiple health issues and those suffering from respiratory illnesses, will be quarantined until the virus 'washes over' and the herd immunity takes place.

Is herd immunity inevitable? Governments the world over just may NOT adopt herd immunity as a preferred public health policy in the face of the ravaging coronavirus epidemic. The majority of governments would want to extend the lockdown and work vigorously on the vaccine. However, at one point they will be faced with mounting pressure to ease the restrictions, leaving people to take care of themselves -- as best as they can.

Meanwhile, the vaccine will take long to arrive and longer to reach everyone on the globe. Over this long term, the virus spread will be restricted owing to the governmental and personal efforts. Yet, the virus will keep moving in societies. But the mortality rates can be kept very, very low if revere quarantine measures are effectively used.



Professor Johan Giesecke, one of the world’s most senior epidemiologists, advisor to the Swedish Government (he hired Anders Tegnell who is currently directing Swedish strategy), the first Chief Scientist of the European Centre for Disease Prevention and Control, and an advisor to the director general of the WHO, lays out with typically Swedish bluntness why he thinks:

* UK policy on lockdown and other European countries are not evidence-based
* The correct policy is to protect the old and the frail only
* This will eventually lead to herd immunity as a “by-product”
* The initial UK response, before the “180 degree U-turn”, was better
* The Imperial College paper was “not very good” and he has never seen an unpublished paper have so much policy impact
* The paper was very much too pessimistic
* Any such models are a dubious basis for public policy anyway
* The flattening of the curve is due to the most vulnerable dying first as much as the lockdown
* The results will eventually be similar for all countries
* Covid-19 is a “mild disease” and similar to the flu, and it was the novelty of the disease that scared people.
* The actual fatality rate of Covid-19 is the region of 0.1%
* At least 50% of the population of both the UK and Sweden will be shown to have already had the disease when mass antibody testing becomes available

Prime Minister Boris Johnson is expected to return to work next week following his recovery from Chinese coronavirus. Boris Johnson had caught the virus in March. After experiencing symptoms for ten days, Mr Johnson was admitted to Saint Thomas’ Hospital in London on April 5th, before being transferred to intensive care on the 6th.

Spokesmen confirmed that while in intensive care, Mr Johnson was not on a ventilator, but receiving oxygen therapy. After spending three nights in ICU, Mr Johnson was moved to a general ward from which he was released on Easter Sunday. Since April 12th, Mr Johnson has been convalescing at the prime minister’s country retreat of Chequers. First Secretary of State Dominic Raab has been deputising as the country’s premier.

Government sources have said that in recent weeks, the prime minister has been slowly increasing his workload. One source told The Telegraph: “The things he’s doing at the moment go way beyond steering the response to coronavirus. The Prime Minister has been asking for policy papers on other things, domestic and foreign, so he has increased his workload significantly. “Everyone is expecting him back in Downing Street some time next week.”

Last week Mr Raab extended the lockdown measures for a further three weeks. It has been hoped that following that second lockdown and after Mr Johnson’s return to work, the prime minister would begin to lift restrictions. However, reports revealed that Mr Johnson has recently told ministers that all proportionate measures should be kept in place in order to avoid the risk of another wave of coronavirus.

A spokesman told The Telegraph: “The big concern is a second peak. That is ultimately what will cause the most damage to health and the economy, if there was an exponential rise once again in cases. The public will expect us to do everything we can.”

According to Johns Hopkins University, the United Kingdom has the sixth-highest number of total confirmed coronavirus cases, with 125,856 people infected. Globally, the UK has the fourth-highest number of deaths at 16,509, as of Tuesday.