Skysnake schrieb:
Wo wir doch bei dem Punkt sind entweder 2G oder 3G dann aber mit Test für alle bei Großveranstaltungen. Wenn das 100 Leute sind ok dann halt ohne Test für alle. Aber wenn da tausende an Leuten zusammenkommen dann verstehe ich nicht warum nicht alle getestet werden bei 3G.
Und wie lange soll das so gehen?
Einerseits heißt es "Die Maßnahmen müssen weg!", dann heißt es "Die Maßnahmen müssen bleiben!".
Nehmen wir an, es gibt eine Tanzveranstaltung (weil man in Bewegung ist und richtig viel pumt, die Luft aber steht) mit 1.000 Leuten und der 3G-Regel. Von den 1.000 sind 70% Vollgeimpfte/Genesene und 30% negativ getestete Nichtgeimpfte (keiner falsch-negativ oder so). Jetzt sind unter den Vollgeimpften/Genesenen Infizierte und es werden 100 Leute angesteckt, 70 davon Vollgeimpfte, 30 Nichtgeimpfte. Alle 30 Nichtgeimpfte werden infektös sein, von den Vollgeimpften Zweidrittel also 47 Personen. Von den 30 Nichtgeimpften werden 20% erfahrungsgemäß hospitalisiert, das sind 6 Patienten, von den Vollgeimpften vielleicht 2%, also maximal einer.
Wer zu viel Freizeit hat:
https://www.medrxiv.org/content/10.1101/2021.08.18.21262237v1.full.pdf Bildchen ab Seite 19.
Es geht um die Wirksamkeit der Impfungen.
Seite 8:
"Peak viral load therefore now appears similar in infected vaccinated and unvaccinated individuals, with potential implications for onward transmission risk, given the strong association between peak Ct and infectivity34 . However, the degree to which this might translate into new infections is unclear; a greater percentage of virus may be non-viable in those vaccinated, and/or their viral loads may also decline faster as suggested by a recent study of patients hospitalised with Delta31 (supported by associations between higher Ct and higher antibody levels here and in35), leading to shorter periods “at risk” for onwards transmission. Nevertheless, there may be implications for any policies that assume a low risk of onward transmission from vaccinated individuals (e.g. relating to self-isolation, travel), despite vaccines both still protecting against infection, thereby still reducing transmission overall. This may be particularly important when vaccinated individuals are not aware of their infection status or perceive that their risk of transmission is low. Importantly, those infected after second vaccination appeared to gain an antibody boost, and higher prior antibody levels were independently associated with lower viral burden."
Now = mit Delta.
"In summary, with Delta, BNT162b2 and ChAdOx1 remain protective against any new PCR-positive and infections with higher viral burden or symptoms, but vaccine effectiveness is reduced, with evidence of significantly different dynamics of immunity against infections with Ct<30 or symptoms following second doses of the two vaccines. With Delta, those infections occurring despite either vaccine have similar peak viral burden to those in unvaccinated individuals. The impact on infectivity to others is unknown, but requires urgent investigation. It further argues for vaccinating as many of the population as possible, since those not vaccinated may not be protected by as substantial reductions in transmission among the immunised population as seen other infections, making herd immunity likely unachievable for emerging variants and requiring efforts to protect individuals themselves. Whilst the current preservation of VE against severe outcomes suggests that allowing ongoing virus transmission and nasopharyngeal viral presence may have limited consequences, the success of this strategy will ultimately rely on universal vaccination (currently not available to most worldwide), uniform protection induced by vaccines including in older individuals, optimisation of vaccine strategies to induce higher levels of mucosal and systemic immunity, and an absence of novel variants which might compromise VE against severe infection."
Edit:
Seite 7 ff:
Es spricht vieles, dass die Impfungen anders als Erkrankung auf die muskosale Immunität (=Schleimhaut) wirken, wenn sie in den Muskel gespritzt werden. Oder verstehe ich das falsch:
"Although testing behaviour bias could contribute to these differences, we also found a stronger protective effect against infections with higher viral burden and/or symptoms from BNT162b2 and ChAdOx1 vaccines, although to a lesser degree than against Alpha. One explanation could be differential effects of vaccination on mucosal and systemic immunity25. In theory, the former is more important for preventing carriage, transmission, and infection becoming established, while the latter is more important for preventing severe disease once infected26. Studies in rhesus macaques showed greater reductions in SARS-CoV-2 viral load in the lungs and prevention of pneumonia, without reducing viral loads in the upper respiratory tract with intramuscular ChAdOx127, and protection against viral replication at much lower concentrations in the lower than the upper respiratory tract with intramuscular mRNA-127328. In mice, an experimental adenovirus vaccine induced strong systemic adaptive immune responses against SARS-CoV-2 and reduced infection in the lungs, but minimal mucosal immune responses when administered intramuscularly29 . Another explanation for differences in VE against infections with Delta versus Alpha is that the former may have a replication advantage in airway human epithelial cells; increased infectivity at mucosal surfaces could facilitate antibody evasion30 . A final explanation could be varying protection by time since second vaccination in the Delta-dominant period, which also differed between BNT162b2 and ChAdOx1. When such time-dependent effects are present, studies with different follow-up will inevitably get different “average” results, and studies when Alpha dominated may predominantly reflect early effects. Regardless of explanation, whilst protection against hospitalisation and death is maintained, “booster” vaccinations may not be needed, particularly since infection post vaccination may provide a natural antibody boost. However, declines in immunity against infection demonstrate this needs to be monitored closely. "
