MODERATOR NOTE while the subject matter is not genealogical in nature, the information is useful for members to decide if they will attend the IAJGS Conference in Philadelphia in August or not.

I totally agree with Yale.
I am a Pharmacist working in a Hospital, and there is an ongoing discussion whether vaccinated people can still transmit the virus.
There are several known cases when people (Hospital employees actually) were sick with COVID-19 back in March-April 2020, and they are sick 2nd time now. 
All those people had antibodies after their 1st time sickness, and yet they got the virus again. Fortunately their symptoms were not as severe as previously (thanks to antibodies).
The point is if someone with natural antibodies (produced as a result of being sick with COVID-19) can get virus again, vaccinated people can get the virus too.
They themselves will be protected (hopefully), but there is still risk of transmitting the virus to people who were not vaccinated.

Another point to mention is the "herd immunity." In order to reach that threshold, at least 70% of the population should be vaccinated. In my opinion, it's impossible to reach it for 3 major reasons.
1. The number of people who refuse to be vaccinated is still very high. In my hospital, it is about 70% employees are vaccinated. I assume the rest just refused. And I am talking about Hospital employees - a general population refusal rate will be much higher.
2. As Yale mentioned, not everyone who wants to get a vaccine can actually get it if he/she has history of severe allergic reaction. It is not a contraindication, and nobody died from getting a vaccine. But still such people might not be good candidates for being vaccinated.
3. Moderna vaccine is approved for people 18 y/o and older; Pfizer vaccine - for 16 y/o and older. But what about people younger than 16? They can contract and spread the virus.

Having all this said, I think people should have a choice of whether they can physically come to the conference or participate remotely. 

Stay safe!

Best regards,

Jeffrey Briskman, Pharm.D.