One is the effectiveness, i.e., how many vaccinated people contract the infection compared to those who got a placebo (a dummy vaccine).
The second part is the vaccine’s potential to reduce hospitalisations and deaths.
So far, governments worldwide have pushed the vaccine for its ability to limit the transmission (as that would bring normalcy to life).
But as more and more data comes in, researchers have realised that the vaccine’s ability to contain the transmission weakens over time.
Right now, as per the efficacy tests, for every 100 unvaccinated people who catch the infection, there are only 5 double-dose vaccinated people who get the disease.
New evidence suggests that over time, for every 100 unvaccinated people who catch the infection, there will be 50 double-dose vaccinated people who will get it.
It is a huge concern, and countries with access to additional doses (e.g., the US) are ready to provide the 3rd dose to the eligible people.
This has divided the world into two halves.
Some consider the 3rd dose administration to be unethical—several countries don’t have enough to cover two doses for their population, and here some countries are planning the 3rd dose.
Now, while the vaccine’s ability to contain the infection reduces significantly over time, its ability to protect against hospitalisations and deaths still remains strong (drops only 10% points from 95% to 85%).
So, governments with additional doses are trying to tackle the question of whether everyone should get a third dose or only the high-risk groups.
The argument in favour of giving the 3rd dose to everyone is that it will attack the source, i.e., if the transmission is restricted, the chances of the disease reaching the high-risk groups will reduce.
People favouring the 3rd dose-for-everyone use Israel as a case study.
After about 80% of its 12+ years population was vaccinated in early 2021, Israel lifted almost all the restrictions.
But cases began to surge in June-July, and by September, 16000 new infections were being reported every day.
The disease eventually caught up with the unvaccinated, high-risk, and under 12 groups, and hospitalisations currently stand at around 1100 (with 700 people seriously ill).
