Attaining herd immunity is definitely more difficult if world population is vaccinated with Astrazenca vs (Pfizer or Moderna..both hard to deliver to third world). [Even worse if the 50.4% efficacy of the chinese vaccine is used]. If herd immunity is delayed a long time then breakout can occur. I hope JnJ has good efficacy and if so the world pop can get it vs something with lower efficacy.
It just means we may never be able to reduce covid to the level of polio in the modern world or eliminate it like smallpox. But we will likely be able to treat it, trace it, and perhaps contain it.
Objectives Is “herd immunity” to COVID-19 a realistic outcome of any immunisation programme with the two main vaccines currently licenced in the UK (Pfizer vaccine BNT162b2 and Astra Zeneca/Oxford vaccine ChAdOx1-S)? More formally, can these vaccines achieve a sufficient level of population...
www.medrxiv.org