Herd Immunity a Pipe Dream?

 


With the proliferation of Covid variants, the goal of achieving herd immunity may be unrealistic.

The South African strain of the virus has shown the AstraZeneca and NovoVax vaccines to be in the 60 per cent efficacy range, far below their effectiveness on what I now call Covid-Classic.

The good news is that the vaccines remain highly effective against the most severe Covid impacts. In other words they significantly reduce the lethality of the range of Covid viruses. They do work to cut the rates of hospitalizations and deaths. 

Shabir Madhi, professor of vaccinology at the University of the Witwatersrand who has been chief investigator on a number of vaccine trials in South Africa, including the Oxford one, said it was time to rethink the goals of mass Covid vaccination.

“These findings recalibrate thinking about how to approach the pandemic virus and shift the focus from the goal of herd immunity against transmission to the protection of all at-risk individuals in the population against severe disease,” he said.

By curbing the rate of severe illness and death, vaccines promise to prevent already strained hospitals from becoming overwhelmed. Good news for both hospitals and health care workers alike.

Ravi Gupta, professor of clinical microbiology at the University of Cambridge, said that it was pragmatic to adopt the approach that vaccines will prevent severe disease and death rather than enabling herd immunity in countries like South Africa. To stop transmission – if it were possible – would mean delivering huge numbers of vaccine doses, which are not working so well, very rapidly.

“We probably need to switch to protecting the vulnerable, with the best vaccines we have which, although they don’t stop infection, they probably do stop you dying,” he said.

Vaccines may not be the hoped-for silver bullet. As some virologists warned at the outset, Covid may just be another lasting part of our future like other viruses that periodically flourish and then recede. 

Nobel laureate virologist, Michael Haughton, now at the University of Alberta, long ago suggested that Covid could be one of those contagions that will require the public to be vaccinated every few years as the virus evolves or mutates. 










Comments

  1. I get the feeling, Mound, the capacity of the virus to mutate rapidly may mean we will be in a semi-permanent state of mask-wearing and distancing. It seems that unlike the flu, Covid-19 will mean we are always playing a defensive game.

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    1. For many, an annual flu shot is now standard. Health authorities try to predict the most likely virus to expect that season, vaccines are produced accordingly, we get the shot and, with any luck, we're spared the affliction. The future of Covid vaccines could follow the same course.

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  2. Expecting a vaccine developed in a few short months to be the end of Covid is pure pipe-dream.
    The rush to go back to 'normal' will only delay the demise of the virus ; perhaps it will be with us for the foreseeable future?

    TB

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    1. The prospect of an enduring virus was raised by Michael Houghton of the University of Alberta, a Nobel laureate virologist. Just as influenza mutates requiring updated vaccines so too Covid. If, however, we can greatly reduce the lethality and severity of Covid-19 that will have to be seen as a medical victory. Now if we could get that minority of the population, the anti-maskers/anti-vaxxers to stop being dicks or have them removed from the general population they imperil, the job of thwarting the virus might become far less challenging.

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  3. I have no doubt that yearly vaccinations will be required to combat covid and it's annual variations.
    I also have no doubt that the anti vaxers are enough in numbers to disrupt the success of such.

    We should not lose sight of the fact that whilst industrialised countries are fighting to resume business as usual rather than defeating Covid much of the less developed nations will be left to crash and burn!
    I have a friend in the polio vaccination business!
    He has reminded me that the fight against aids by GW Bush was not for western altruistic reasons but to facilitate trade.
    You cannot trade with a country where there is risk of exposure to disease .
    And so it is with Covid; business before pleasure!!

    TB

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  4. Agreed:
    " Covid could be one of those contagions that will require the public to be vaccinated every few years as the virus evolves or mutates. "

    or will it become - every few months? Pandemic is barely one year old and look where we are now!

    Silver linings: Look out Nike & Reebok etc:
    at least kids will have a real reason to be 'brand conscious' in the future.

    ""First, it is fortunate that we have multiple other vaccines, such as those developed by Pfizer, Moderna, Novavax and Johnson and Johnson, that preliminary laboratory studies show to be somewhat less effective but still protective against B.1.351," Medford explained. "Second, when necessary the technology underlying mRNA vaccines allows for the rapid development of vaccine boosters that can specifically protect against variants such as B.1.351."

    He added, "Third, to prevent the spread of B.1.351 and the emergence of new and similar variants, we can and must aggressively crush quickly the circulation of the SARS-CoV2 virus, including all its variants, through mass vaccination and the rigorous adherence to mask wearing, social distancing and handwashing."" via Salon

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  5. .. we adhere to extremely tight discipline in this household and my son's.. We are a bubble of two. My son's is a household of 4 adults, 3 large dogs & all highly social but now dealing with an entirely new social landscape. They live on a beach, we live in East York, an area evolving from older Greek to younger Muslim and lots of others in between.

    We all shop - groceries, booze, take out and delivery, mask, wash.. We pick our spots re shopping, avoid lineups. We are a 7 minute walk if that.. From Michael Garron Hospital.. and though I have shot there many times, my son was born there.. I do not want the next visit to be due to COVID

    My family doc has delivery privilages there.. and Dr Michael Warner is chief of ICU & Critical Care. He offers sparse opinion & actual experience, even moreso after one full year of he & his compadres on the very front line. His thoughts re the varients, school openings, economy opening, LTC abominations are succinct, sparce, blunt. The hospital is undergoing massive addition construction & he is very supportive of all the trades on site in bitter cold & under duress onsite. He is very special to this community.

    Boss and I lay low, run a tight little ship. Neither in any damn rush to get inoculated. I know the longer we wait, the more science is appraised, new vaccine refinement will take place. We are not suffering.. just pissed at where society has found itself. We both follow facts & exemplar's very closely.. Did I say VERY ? And compare notes over morning tea / coffee.. and again at supper time or during the evening.. PBS, BBC, TVO.. and she is expert level channel flipper.. Intolerant of bullshit, pedantic nonsence, posturing. She watches while surfing and tweeting with her homies & secret cabal.. Plus has two radio stations on the go in different rooms 24/7.. Plus the Leaf game

    Via Twitter mainly, I try to reflect the perspectives of exemplars.. Not Doug Ford or Jason Kenney or the various Ministers aligned on TV in the Flying V Formation.. blathering out the holy blessed Talking Points

    Dr Fauci is great in my view.. Ms Hinshaw was dragged into Jason Kenney's UCP cage, Ontario's Dr Williamson - same deal, but also seems a burned out medical hack, going with Ford's idiot flow

    Summary.. Form your own opinions & rationale - behave or believe accordingly. Taking the word of Main Media puts you at dire risk in my humble view

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