Italy isn’t sure if giving the Astra Zeneca vaccine to people over age 55 is a good idea, and recommends other vaccines.
My understanding of the Astra Zeneca vaccine is that even though the efficacy is lower at around 65% vs 90-95% for the Pfizer and Moderna vaccines, it does do a good job of lowering the rates of serious cases of covid and hospitalizations. People who get the AZ vaccine may be at higher risk of contracting a mild illness, but they have low risks of death and hospitalizations.
But one concern of Covid is we aren’t sure yet what the long term complications are. Its not just about being hospitalized now from covid, its about the long term damage the disease may cause. Covid may cause circulatory, lung, neurological and other issues years down the line. If a person is concerned about that, can they request an mRNA vaccine instead, even if it means they have to wait a month or two extra? What about people who are concerned that if they get a vaccine that has a higher risk of contracting a mild illness, that even though they may not end up hospitalized from covid if they catch it, it could open the door for long term lung and circulatory issues from having gotten covid in the first place.
Basically is there any kind of infrastructure that says a person can say ‘I’m worried about long term complications of contracting covid, so I want a vaccine with the highest efficacy rating even if it means I have to wait longer’?
Granted I don’t think anyone really knows the long term complications of covid or how vaccines will play into it. But one would assume a vaccine that prevents any illness will probably protect more from the long term damage than a vaccine that high a higher risk of contracting covid even if its mild.
As of right now, in the US, the answer is going to be some combination of 1) it depends on where you live and 2) no one knows. I didn’t know which shot I was going to get until they put it in my arm: it was never mentioned in any of the stages that led up to the appointment. I think it’s quite possible that the vaccination site was set up to switch as needed, based on what the state could send. But I don’t know.
I am sure I could have refused the shot, but I don’t know how rescheduling would have worked. There must be a way–emergencies happen–but I think I would have gone back the end of a very long line, and no promise that the next time would have been any different. It could be a really long process.
I wonder if the better strategy might be to take what you could get now, and add the second vaccine later, when it becomes more common (and so easier to specify which you want). I don’t know if there’s any current medical wisdom on stacking vaccines.
My father said where he went they had one table for Moderna and the others were Pfizer (I think); the tables were labeled. He said the Moderna table was empty but we don’t know if that means they ran out or never got any.
Right now, no (the J&J vaccine is 65% effective, the Astrazeneca one is at least that, but the data is dirty). The priority is getting shots into arms as fast as possible and the logistics of that are tough enough without offering people choices. I suspect over the next two years, people who are vaccinated with the J&J vaccine will be able to get revaccinated, and they are talking about this being like the flu vaccine, with a tweak and a revaccination every year.
All of them have the same sort of “your chance of getting severe Covid goes way down” mechanism…with some chance at preventing infection. Of course, the more effective vaccines seem to have more effective results. None of them prevent all illness.
It should be noted that the test and evaluation protocols in the different trials are not really comparable. The Modena and Pfizer trials only performed antigen testing on people who were symptomatic, so it does not evaluate effectiveness against asymptomatic infections (or potentially people who are symptomatic but did not recognize and report their symptoms to the trail), while the AstraZeneca UK trials that indicated a 62% efficacy involved comprehensive testing of the entire test population and thus caught asymptomatic infection, which is at least half of all infections, and asymptomatic patients are known to sometimes be carriers involved in superspreading events. The AstraZeneca trial that was run in Brazil without comprehensive testing and indicated efficacy levels comparable to the Modena and Pfizer trials. This is crucial because if the actual efficacy is reduced to ~60% level, it is insufficient to attain a herd immunity threshold, and we will need to have comprehensive vaccination and surveillance program indefinitely.
Regardless, all of vaccines being evaluated for EUA by the United States have demonstrated significant reduction in severe morbidity, and pretty much eliminated primary mortality (although infection may exacerbated pre-existing underlying conditions resulting in mortality) and the percentage of really adverse reactions appears to be the same per capita order of magnitude as the seasonal influenza vaccine. I would personally prefer the adenovirus-based vaccines because it is a more proven technology and doesn’t have the logistical issues that could compromise effectiveness if cryogenic temperatures are not maintained during transport and storage, but at this point any vaccine will provide at least a good measure of protection for an indefinite period of time. I have some concerns about the persistence of protection of the mRNA vaccines if the second shot (which functions as an adjuvant to reinforce the memory B-cell response and may provide cross-reactive protection against variants) if not received within the demonstrated schedule, but I suspect we’ll continue to see more vaccine developments, especially if the variants turn into actual strains that evade immune response provided by the initial vaccines. The poliomyelitis vaccines went through decades of developments and improvements and the IPV still requires a sequence of three doses given months apart to get up to a 99% efficacy level, so I expect that we’ll see progressive refinements in these vaccines to get higher efficacy and lower adverse effects.
It may depend on whether you have any underlying health conditions for which live or attenuated vaccines are contraindicated. I am immunocompromised (MS), and my neurologist emphatically advised me to stay away from the AZ vaccine.
This was also the observation of an immunology expert that was recently interviewed on CBC. The particular context of the conversation was the pending approval of a new Johnson & Johnson vaccine, which superficially appeared to be less efficacious than Pfizer or Moderna. He said that because of differences in evaluation protocols they weren’t directly comparable. He also said that the rated effectiveness of the J&J vaccine against cases serious enough to require hospitalization was at least as good as that of many other typical vaccines for many other diseases.
Yep. And also as good as the COVID shots now authorized in the United States. It’s just the mild cases where there seems to be a difference.
Also, J&J is doing a study on second doses. If it turns out that a booster helps – and I’m guessing the chances of that are more than 50-50 – people who took that jab will be offered a second before too long (except maybe in impoverished nations). As for there being a longer time between first and second shots, this may be a plus.
They all seem good. The Lancet has an article today that makes even the Sputnik sound good to me. mRNA right now looks like it could be the long-term winner, but I wouldn’t delay in order to get what may or may not be better.
I forgot to mention that J&J is supposed to be a one-shot vaccine, which is definitely an advantage over the others. I wasn’t aware that they were studying the possibility of second doses.
That’s why we should prepare ourselves in advance for when the Israeli results start coming in about 2nd dose immunity levels. They are testing like crazy and their numbers will undoubtedly be below 90-95%.