Until we have challenge trials, how do we know whether or not other variables, such as natural herd immunity and seasonality are not also significant contributing factors to the 'substantial reduction'?
Covid vaccination linked to 'substantial reduction' in hospital admissions
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Re: Covid vaccination linked to 'substantial reduction' in hospital admissions
#32Until we have challenge trials, how do we know whether or not other variables, such as natural herd immunity and seasonality are not also significant contributing factors to the 'substantial reduction'?
You have a control group of unvaccinated people.
Re: Covid vaccination linked to 'substantial reduction' in hospital admissions
#33Earlier quoted context omitted.
The AZ vaccine is more effective than the BioNTech one? That's extremely interesting.
I wouldn't read too much into that small difference. This study wasn't really designed to show which one works better. The bigger takeaway is that both show significant protection even with just one dose (which presumably rises after the second dose).
Agree. I can't find the right information but I suspect that the headline figures from the different vaccine trials may be generated by somewhat different counting methodologies. I think that some of the trials counted from day 1 of the vaccination, and some of them from day 15 - but I am hoping that someone has the actual information!
Re: Covid vaccination linked to 'substantial reduction' in hospital admissions
#34Data is very encouraging. Presently this battle is essentially a race between the current vaccines (which data indicates are very effective against current strains) and eventual variants that will make the current vaccines less effective (or in the worst case ineffective). The mutations aren’t really a question of if just when. Vaccine data on some new strains is concerning and potentially an early warning of things…
there's no race. If this virus can mutate into something that renders the vaccine ineffective it will. Brazil and Mexico and the rest of the developing world will give it ample opportunity no matter how quickly we roll out the current drugs. It took decades to hunt down smallpox.
There is a race because the more people that are infected with the current strains, the more chances that the virus will have to evolve into newer strains.
It is also believed that new strains are more likely to appear in places where the pandemic is out of control, with a large number of people currently infected and also a large number of people that already have some immunity to previous versions of the disease. This provides the selective pressure that can lead to new variants arising. Therefore, getting the pandemic under control using vaccinations and other measures is key to reducing the number of new variants that pop up.
Re: Covid vaccination linked to 'substantial reduction' in hospital admissions
#35Data is very encouraging. Presently this battle is essentially a race between the current vaccines (which data indicates are very effective against current strains) and eventual variants that will make the current vaccines less effective (or in the worst case ineffective). The mutations aren’t really a question of if just when. Vaccine data on some new strains is concerning and potentially an early warning of things…
there's no race. If this virus can mutate into something that renders the vaccine ineffective it will. Brazil and Mexico and the rest of the developing world will give it ample opportunity no matter how quickly we roll out the current drugs. It took decades to hunt down smallpox.
There certainly is a race. The slower we go the more spread. The more spread, the more variation. The more variation, the more likelihood of a vaccine-resistant strain taking hold.
Even if it’s a long-term certainty, much better to be well-equipped to respond to it, which we simply are not at the moment.
Re: Covid vaccination linked to 'substantial reduction' in hospital admissions
#36Until we have challenge trials, how do we know whether or not other variables, such as natural herd immunity and seasonality are not also significant contributing factors to the 'substantial reduction'?
You have a control group of unvaccinated people.
These people are starting to get vaccinated now though[1], which actually causes issues with the study.
[1]:https://www.npr.org/sections/health-shots/2021/02/19/9691430...
Re: Covid vaccination linked to 'substantial reduction' in hospital admissions
#37"By the fourth week after receiving the initial dose, the Pfizer and Oxford-AstraZeneca vaccines were shown to reduce the risk of hospitalisation from Covid-19 by up to 85 per cent and 94 per cent, respectively. Among those aged 80 years and over - one of the highest risk groups - vaccination was associated with an 81 per cent reduction in hospitalisation risk in the fourth week, when the results for both vaccines we…
The AZ vaccine is more effective than the BioNTech one? That's extremely interesting.
With my very little biology knowledge I could imagine it being linked to the much stronger reaction many people seem to have to the AZ vs. the BioNTech one, resulting in more solid immunity.
Re: Covid vaccination linked to 'substantial reduction' in hospital admissions
#38Earlier quoted context omitted.
there's no race. If this virus can mutate into something that renders the vaccine ineffective it will. Brazil and Mexico and the rest of the developing world will give it ample opportunity no matter how quickly we roll out the current drugs. It took decades to hunt down smallpox.
Isn’t it almost certainly the case that the ‘unstoppable’ thing it turns in to will basically be more akin to a general cold though? The thing that makes this virus deadly is also the thing we are coding against in the vaccine.
Not necessarily. For example, some of the more recent SARS-CoV-2 variants spread more easily because the virus causes a more severe infection, which is transmissable for a longer period of time. It's also not a guarantee that the virus will evolve into something weaker. There are serious diseases like measles and smallpox that have circulated for thousands of years while remaining as deadly as they ever were. Sometimes, the disease not being as deadly after a while can be a result of natural selection selecting for more resistant individuals (after many deaths), not of natural selection selecting for less deadly pathogens.
Re: Covid vaccination linked to 'substantial reduction' in hospital admissions
#39Earlier quoted context omitted.
there's no race. If this virus can mutate into something that renders the vaccine ineffective it will. Brazil and Mexico and the rest of the developing world will give it ample opportunity no matter how quickly we roll out the current drugs. It took decades to hunt down smallpox.
Isn’t it almost certainly the case that the ‘unstoppable’ thing it turns in to will basically be more akin to a general cold though? The thing that makes this virus deadly is also the thing we are coding against in the vaccine.
What your saying is a likely long-term outcome. But the reason we see milder viruses circulating as an “end-game” is just because we don’t tend to deal with non-threats. There is no rule that mild strains are a given outcome of mutation. You just won’t see super-deadly variants last long-term because it quickly turns into an us or them battle that we have so far been able to win.
Re: Covid vaccination linked to 'substantial reduction' in hospital admissions
#40Earlier quoted context omitted.
You have a control group of unvaccinated people.
These people are starting to get vaccinated now though[1], which actually causes issues with the study. [1]: https://www.npr.org/sections/health-shots/2021/02/19/9691430...
That's the clinical trials, but it should be reasonably straightforward to do observational studies on COVID hospitalizations cross-referenced with vaccine status.
There are plenty of millions of people who haven't yet (or won't ever) get vaccinated to serve as a control.