[lvlrsSTI]

Simple question. If they feel their vaccine is able to handle CoVid … why 21days quarantine for all travellers include those using their vaccine. 

No need to if, even, why, how, that, when …...

Question: Can you tell me why Britain, Israel and Spore are getting thousands of breakthrough cases everyday after majority of populations are fully vaccinated?

Your understanding is, vaccines are 100% effective against Covid, Delta and many other variants. 

Wrong lah, vaccines are only effective to some extent but are unable to protect us from Delta variant, that is why we are having so many breakthrough cases everyday. Must wait for the new vaccines that are effective against Delta and other variants in coming year.

Question: Why quarantine is required for people entering a country from overseas even after these people’s PCR test results are negative 72 hours before departure and they are fully vaccinated?

Answer: 1. Vaccines are only effective against Covid snd Delta variant to some extent, much less than 100%; 2. Although PCR test shows negative, there are chances for a passenger to get infected on the plane and at airport....there are number of such cases reported before...to be 100% sure these passengers have to do another PCR test upon arrival at the destination airport. 3. Quarantine is required because it takes time for a person to show symptoms after getting infected. A person has negative PCR test result before boarding the plane, later gets infected on the plane by another passenger, upon touchdown his PCR test result on the spot could still be negative. A few days after he starts quarantine at hotel, he starts having fever and shows other Covid symptoms, when the doctor does another PCR test, the result is Positive.

Therefore to play safe quarantine is still required. It is too risky to trust vaccination history as vaccines are not 100% secure, and too casual to accept PCR test result performed 3 days earlier.