Since the vaccines didn’t stop transmission, can’t the same be said of them?
So yes, covid vaccines do that.
Yes, the CDC changed its definition of vaccine to be 'more transparent' https://www.king5.com/article/news/verify/coronavirus-verify...
> [T]he CDC changed its definition of vaccine from "a product that stimulates a person's immune system to produce immunity to a specific disease, protecting the person from that disease" to "a preparation that is used to stimulate the body's immune response against diseases."
The mechanism of a flu or covid shot is exactly the same as any other vaccine; the only difference is the degree of efficacy due to human mucosal immunity not having evolved to fully block infection from respiratory viruses.
https://journals.plos.org/plospathogens/article?id=10.1371/j...
> "While it is hoped this will be the case, the scientific community does not yet know if the Pfizer-BioNTech COVID-19 Vaccine will reduce such transmission."
[1] https://www.fda.gov/emergency-preparedness-and-response/coro...
> It's obvious looking at the data that vaccines reduce transmission.
Are you questioning my faith?
The Science Pope doesn't like to hear such heresy. Better watch out or else he'll sic the Science Inquisition on yo' aess!
I don't.
I know 2 people that caught covid after being vaccinated. I've never caught it. Most people I know never caught it. And it would be even worse without vaccines. Y'all are doing something wrong over there.
Anecdotal evidence can be dismissed with anecdotal evidence.
I tested myself randomly one time, no symptoms, and tested positive.
Asymptomatic infection is quite common with covid.
Individual experiences dont give any indication of population level outcomes - there is too much variability.
Some people see their cancers spontaneously go into remission but you wouldnt make a claim that cancers usually go into remission by themselves.
Your personal attack is again HN rules. And I'm not sure where you're coming from - I've been vaccinated.
This "vaccines can do no wrong" bandwagon is as damaging to science as the "vaccines are all bad" group.
They were very slow to confirm side effects (remember when people suffering with heart issues were ridiculed and ignored?).
Very slow to let everyone know that it wouldn't actually stop transmission (remember when we were told to get it to protect grandma? Or how about the messaging that 'breakthrough cases are very rare').
Very slow to reveal that effectiveness waned quite quicky.
These issues were quite obvious from the beginning. It's taken two years and only now can these be openly discussed without becoming a social pariah.
What the FDA said, simplified, is there is no evidence either way whether a breakthrough COVID case in a vaccinated person poses a greater risk of infection to other vaccinated people, BUT past vaccinations have shown that those other vaccinated people are still protected and therefore that should be the assumption here until refuted.
Original:
Q: If a person has received the Pfizer-BioNTech COVID-19 Vaccine, will the vaccine protect against transmission of SARS-CoV-2 from individuals who are infected despite vaccination?
A: Most vaccines that protect from viral illnesses also reduce transmission of the virus that causes the disease by those who are vaccinated. While it is hoped this will be the case, the scientific community does not yet know if the Pfizer-BioNTech COVID-19 Vaccine will reduce such transmission.
"These findings suggest that, although vaccinated and/or previously infected individuals remain highly infectious upon SARS-CoV-2 infection in this prison setting, their infectiousness is reduced compared to individuals without any history of vaccination or infection. This study underscores benefit of vaccination to reduce, but not eliminate, transmission."
Naumova EA, Dierkes T, Sprang J, Arnold WH. The oral mucosal surface and blood vessels. Head Face Med. 2013 Mar 12;9:8. doi: 10.1186/1746-160X-9-8. PMID: 23497446; PMCID: PMC3639856.
It also has antibodies (humoral immune response).
Immunoglobulin A (IgA) is the most abundant antibody isotype in the mucosal immune system.
Li Y, Jin L, Chen T. The Effects of Secretory IgA in the Mucosal Immune System. Biomed Res Int. 2020 Jan 3;2020:2032057. doi: 10.1155/2020/2032057. PMID: 31998782; PMCID: PMC6970489.
And the vaccine triggers the development of those antibodies.
We evaluated the serum anti-spike (anti-S) IgG, anti-nucleocapsid (anti-N) IgG and anti-S IgA response following vaccination against SARS-CoV-2 in a cohort of first-responders. Among the 378 completely vaccinated participants, 98% were positive for anti-S IgG and 96% were positive for anti-S IgA.
Montague, B.T., Wipperman, M.F., Chio, E. et al. Elevated serum IgA following vaccination against SARS-CoV-2 in a cohort of high-risk first responders. Sci Rep 12, 14932 (2022). https://doi.org/10.1038/s41598-022-19095-7
Essentially the current vaccines wouldn't give any mucosal protection worth mentioning in itself, but since there are (hopefully) relevant lymphocytes in circulation, the host has more in the way of specific countermeasures ready to infiltrate from the bloodstream and shut down the worst of the shedding, sooner than if the specific immunity had to be developed first.
So we'd have more or less unfettered susceptibility for getting infected (superficially) and pretty much just as high levels of infectious excretions, but for maybe half as long a time at the highest levels.
Would you happen to know if that picture still holds?
Similar statistical model as control rods in a nuclear reactor - they don't stop neutrons, they significantly reduce the numbe of free neutrons flying about and avoid an exponential increase and runaway chain reaction.
> Seat belts reduce serious crash-related injuries and deaths by about half
Do you have some evidence that the vaccines are in that ballpark against infection/transmission in 2023?
And even if it was 99% effective, it certainly doesn’t justify leaving drugs in the market where one mutation potentially has humanity ending consequences.
The Covid vaccine was great for helping the elderley and vulnerable from day one. For the rest of us, it was a busted flush.
Similar thing happened in Manitoba where 80% of an elderly long term care facility got infected despite everyone being fully vaxxed.
Comparing a seat belt to a permanent medical procedure inside the body is asinine. Seat belts don’t go inside the body, can be taken off, don’t need a new belt on top of old one every few months, get recalled if defective, manufacturer can be sued, belts don’t cause blood clot or heart inflammation.
There is not a vaccine in the world that provides 100% protection to every individual. ALL vaccines work by reducing R0 to <1 so outbreaks shrink rather than growing.
I can’t believe we’re still doing the nutty antivax thing in 2023.
They are not in the same category at all
Vaccines are typically very effective. So effective they can eliminate a virus among vaccinated populations.
Covid-19 vaccines are sorta effective. They didn’t eliminate virus transmission among vaccinated populations. But they reduced the severity of cases.
Pretending the vaccines weren’t underwhelming in terms of efficacy doesn’t do us any favors, because people know from their own experience that most vaccinated people have had Covid.
As I stated above the COVID vaccines didn't eliminate transmission they reduced transmission rates.
I've just replied to another comment and provided two (of many) statistically significant studies (for professional epidemiologists) that confirm that (specifically for two vaccines in the UK). There are other studies across the globe that affirm the same conclusion.
The important truths about "people know from their own experience that most vaccinated people have had Covid." are that many vaccinated people had COVID .. a milder form with greatly reduced rates of hospitalisation, reduced rates of critical care, and reduced rates of death.
How does the flu vaccine work, except by providing some chance of protection to those taking it?
Just like covid vaccines, flu vaccines also protect unvaccinated people by making it less likely for them to be exposed to the virus in the first place.
The critical thing that antivax people miss is that they are both individuals and members of a population. Reducing the odds of infection for individuals has an exponential effect on reducing the odds for a population.
I meant this statement. No-one has ever suggested that the flu vaccines will stop the overall flu outbreak from growing.
Reducing the odds of infection also strongly depends on the extent to which that vaccine provides sterilising immunity.
Expressing safety concerns and having a rational discussion about a new genetic therapy is not a "nutty antivax thing", and it is disingenuous and argument in bad faith to suggest that it is.
The FDA defines "Gene therapy products. Human gene therapy/gene transfer is the administration of nucleic acids, viruses, or genetically engineered microorganisms that mediate their effect by transcription and/or translation of the transferred genetic material, and/or by integrating into the host genome."
mRNA (Pfizer and Moderna's vaccines) and adenovirus vector (Janssen vaccine) are the transfer of nucleic acids and viruses that mediate their effect by translation, and transcription then translation, respectively, of the transferred genetic material.
The FDA defines them as such: "Gene therapy products. Human gene therapy/gene transfer is the administration of nucleic acids, viruses, or genetically engineered microorganisms that mediate their effect by transcription and/or translation of the transferred genetic material, and/or by integrating into the host genome."
You may have misunderstood that I was drawing a distinction and suggesting that they are not "vaccines," which some people do. Similarly, but from the opposite point of view, you may also be suggesting that genetic therapies and vaccines are non-overlapping categories. I reject the false dichotomy.
For example (and there are many):
Data from studies in the United Kingdom showed that both the Pfizer and AstraZeneca COVID-19 vaccines were effective in preventing onward transmission of the virus to close contacts in case of breakthrough infections.
In one study among the general population in the United Kingdom, the effectiveness against transmission from breakthrough infections to household contacts from 21 days after the first dose was 47% (95% CI: 37–57) for the AstraZeneca COVID-19 vaccine and 49% (95% CI: 41–56) for the Pfizer COVID-19 vaccine. [1]
Another study from the United Kingdom reported that, among healthcare workers, who predominantly received the Pfizer COVID-19 vaccine, vaccination was associated with a 30% (95% CI: 22–37) reduction in transmission of SARS-CoV-2 to household contacts. [2]
[2] Shah ASV, Gribben C, Bishop J, et al. Effect of vaccination on transmission of COVID-19: an observational study in healthcare workers and their households (preprint). medRxiv 2021.
The first study you mentioned is:
https://khub.net/documents/135939561/390853656/Impact+of+vac...
This is a study of less than 2 months between "4 January 2021 to 28 February 2021". This is long long before delta and omicron and newer variants came. I specifically mentioned the changes which Delta brought.
Second study you cited is:
https://www.medrxiv.org/content/10.1101/2021.03.11.21253275v...
This is once again an outdated study from "8th December 2020 to 3rd March 2021" which is long before Delta, Omicron, and newer variants.
People repeatedly keep citing outdated studies from before Delta, Omicron and don't acknowledge the changes which those variants plus waning immunity brought. Also any study which doesn't measure asymptomatic infections is worthless.
Here's a better example. In a 94% vaccinated study, 56% reported being unaware of their infection:
https://jamanetwork.com/journals/jamanetworkopen/fullarticle...
What happens when infected people go around not knowing they are infected? They infect others and have a false sense of safety.
Seroprevalence data also shows 90% of population has already been infected. If the vax was preventing transmission, that wouldn't be happening.
" Since the vaccines didn’t stop transmission, can’t the same be said of them? "
with the broadly true statement that no vaccine that I'm aware of stops transmission .. they ideally reduce transmission* (being effectively not a vaccine if they fail to slow spread through a population (or mitigate effects of a virus that does spread)).
The studies I cite are just two (of many) first off the rank that demonstrate that the two of the more widely used vaccines did indeed slow transmission at the time they were used.
> Here's a better example. In a 94% vaccinated study, 56% reported being unaware of their infection:
I read that with interest the entire way through,
* it fails to support a claim that "vaccines did not reduce transmission of Delta or Omicron variants"
* it supports a claim that "vaccines reduced the effect of having a COVID variant (to the degree that most did not even realise they'd been infected)"
The specific statistical reason that your "better example" doesn't address the transmission rate (through vaccinated Vs unvaccinated populations) is that it exclusively looks at people infected and the bulk of those are vaccinated.
There's no larger view there of infection rates in a bigger population, and no differential look at infection rates in unavaccinated Vs vaccinated.
What the study confirms (re: transmission) is something I conceded in my first coment: vaccines do not stop transmission
(again, they ideally reduce transmission rates (not addressed in your 'better' study)).
If you're interested in a longwinded careful, multi factor analysis and model type paper (of which there are many) one such example is
https://www.frontiersin.org/articles/10.3389/fpubh.2022.8230...
which is detailed but lacks any clearcut gotcha messages .. it bears close reading and laments in places the lack of early vaccine uptake in the population (Australia) during the Delta and Omnicron waves (ie. supports vaccines reducing transmission rates, doesn't dwell on it as not enough people are vaccinated at that time and so looks at other mitigations).