Your brother needs to apply separately from your parents. Assume they are all vaccinated. Getting an answer before December may be difficult. It’s unclear what wait times will be like now that the borders are opening more to those who are vaccinated. Is your brother working full-time? Does he own property? Does he have his own finances? Has he travelled to places like the US, UK, Australia in the past 5-10 years? How is he able to take a month off during a pandemic as a physician? Young single can struggle to get approved because they have minimal ties to their home country to prove that they will return and their finances may not be very good at their age.for one month i.e in December. My brother is 26years old and he is a doctor.