More "unlinked" cases as more get vaccinated.

 Expect more "unlinked" cases.

The fact is the Delta variant is more transmissible and is able to make "breakthrough" infections - infecting those already vaccinated.

This is because the Delta variant has a viral load 1000 times more than the previous variants. 

So the viral load is able to overwhelm the antibodies that the vaccinated body is producing, and the person will fall ill.

If you are vaccinated but get infected with the virus, whatever the variant, you are likely to be asymptomatic, or have very mild course of the illness. So you might think its just the common cold or just the sniffles, and do not seek medication attention and so do not get picked up by the pandemic monitors.

And while vaccinated people have a lower viral load and are less likely to spread the virus, they still can. So in a community with a mix of vaccinated and unvaccinated, and a highly transmissible variant like the Delta variant, you can have vaccinated people with the virus (Delta variant) but not have severe enough symptoms to be tested and identified as infected, and they can spread the virus to the unvaccinated, who will more likely get severely ill and be identified as infected, but "unlinked" to any identified cluster or infected.

Which is why, even if you are vaccinated, you have to continue to wear a mask, practice safe distancing, and adhere to all other restrictions. 

Yes, you thought you could fly once you are vaccinated. 

So did I. 

But we need to protect the rest of the unvaccinated.

The number of unlinked cases have been increasing even though the vaccination rate has been increasing.

If you understood the explanation above, you will see that this is logical and reasonable.

This chart shows the linked and unlinked cases. The number of unlinked cases are increasing. As explained above, this is actually a consequence of greater vaccination and a more transmissible and infectious Delta variant.

But, vaccination is still protective and helpful. The chart below shows that 99.8% of those infected have mild or no symptoms. Even partially vaccinated, 97.7% have mild or no symptoms. So vaccines do protect. 

But to take the perspective of the vaccine-hesitant, even unvaccinated, 94.9% of people have only mild or no symptoms. So does it make sense to vaccinate 100 people when if these 100 people were NOT vaccinated, only about 5 of them will require intensive medical intervention (oxygen or ICU)? 

Except that we are talking about whole populations. And the percentages are rather fine. So 94.9% of unvaccinated people will have NO or MILD symptoms. Conversely, about 5 in a 100 will have serious symptoms requiring medical intervention, rounded down. But it is 51 in 1000 or 510 in 10,000.

If these 10,000 were all partially vaccinated, the percentage of mild or no symptoms increases to 97.7%. So only 23 in a 1000 will need medical intervention (instead of 51). Or 230 in 10,000. 510 patients have been reduced to 230. 280 patients have been saved the inconvenience of being hospitalised or in ICU. 

If all 10,000 were fully vaccinated, only 20 would be hospitalised in ICU or require oxygen supplementation. 490 people would have been spared ICU hospitalisation. The difference of 20 people in ICU vs 510 people needing to be ICU is logistically VERY significant. 

And we are dealing with a very transmissible virus. 

To date, more than 64,000 people have been infected in Singapore. Most were before vaccines were available, so about 5% required medical intervention - so about 3200. Fortunately, not all at the same time or our hospitals would have been overwhelmed.

If we are to transit to living with Covid-19, we need to be adequately protected. If you CAN be vaccinated, you should. If you choose not to be vaccinated, then you are in fact choosing to have a chance of being hospitalised if you are infected. Five out of 100 people infected will be. 

In Singapore the current infection rate is about 11,000 per million. Or about 11 in 1000. It would seem quite low. But that is in part because of mask rules, and social distancing rules and lockdowns/phase 2. All these have limited the infection rates as intended.

However, when Singapore ease all the pandemic restrictions, when we start living with the endemic Covid-19, infection rates will rise. We cannot say how much it will rise, but in other countries, infection rate of the population has been as high as 10% or even 19% in some cases. These might have almost NO pandemic measures in place, or very lax enforcement of such measures.

Worldwide, the infection rate to date averages about 2.5%.

Let's work with that because 10% or 19% is too extreme to consider.

If the infected are protected by vaccine, most would not need hospitalisation,

If not protected, there is a 5% chance the infected will suffer. 

So... you have a (say) 2.5% chance of being infected, and if you are infected, there is a 5% chance you will suffer severe symptoms. 

But you're in Singapore. You'll be fine. Only 37 deaths so far.