'At the club ... we have to encourage players to behave in a disciplined way with regards to contact.'
Manchester United manager Ralf Rangnick said the club had to ensure its players were vaccinated following a COVID-19 outbreak that led to the postponement of their last two Premier League games.
"At the club ... we have to encourage players to behave in a disciplined way with regards to contact, we also need to make sure we have most of the players vaccinated," Rangnick told reporters.
"As far as I'm aware, we have a high record of vaccinated players here in our club."
United last played in a 1-0 win over Norwich City on December 11 and their fixtures against Brighton & Hove Albion and Brentford could not go ahead after a string of COVID-19 cases left them with just 11 fit players, three of which were goalkeepers.
They now have nearly their full squad available for a trip to Newcastle United on Monday.
"The past two weeks show that even if you are being vaccinated two or three times, you can still be catching the virus, especially the new virus (Omicron)," the German said.
"You are not being protected but at least you are being protected from severe symptoms.
"And as far as I know, most of our players who were tested positive, at least they had very, very weak symptoms and they didn't suffer from that."
United trail leaders Manchester City by 17 points but have played two games fewer.