When the elderly take first dose of vaccine , all
Precautions need to be in place till the second dose. Follow your provider's recommendations about when to get the second dose.
Can be three weeks for Pfizer and four for Moderne and AstraZeneca The second dose of the Pfizer vaccine is typically given after three weeks and the Moderna after four weeks.

After the second dose, it probably takes another two or three weeks to develop the optimal degree of immune protection.
So you need to keep up the precautions till atleast six weeks after talking the first shot of vaccine.

A few weeks after the second dose, studies have shown that the vaccine efficacy is approximately 95%. That's a very high level of protection but it's not 100%. So even after getting both doses of the vaccine, you could still get Covid-19, but your chance is much lower. And if you did get it, the disease will be less severe .
BUT CAN YOU PASS IT ON.
Yes u can so still observe the social distancing norms while visiting non vaccinated people especially children