Here is a bit of background on these Alexandrian manuscripts...
"The Minority Texts were corrupted by Egyptian Gnosticism mostly in Alexandria with many changes, which are mostly deletions. The Gnostics were a group that did not believe in the virgin birth, that Jesus was the Son of God, that Jesus was resurrected to heaven, that Jesus was the Creator, or that Jesus made atonement for our sins.
There are many alterations in the Alexandrian manuscripts (Minority Text), the Codex Alexandrian, Codex Sinaiticus and Codex Vaticanus, often a single manuscript being amended by several different scribes over a period of many years.
The Minority Texts omit approximately 200 verses from the Scriptures and contradict themselves throughout."
Here is some more background on the corruption of the Minority Text from another site....
"...almost all modern English bibles translated since 1898 are based on the Minority Text (this includes the New American Standard Bible, the New International Version, the Living Bible, the New Revised Standard Version, the New World Translation, the New Century Version, the Good News Bible, etc.). These bible versions are only supported by about five of the over 5,000 manuscripts in existence, or about .1% of all manuscripts, which is why it's also known as the "Minority text.".
The two most prominent manuscripts of the Minority Texts are the Vaticanus and the Sinaiticus....These Minority Texts frequently disagreed with each other as well as with the Majority Text, and also contained many obvious and flagrant mistakes. Up until the late 1800s, the Minority Texts were utterly rejected by Christians.
The fact that these two manuscripts may have been older does not prove they are better. More likely it indicates that they were set aside because of their numerous errors....
The Vaticanus, which is the sole property of the Roman Catholic Church, and the Sinaiticus, are both known to be overwhelmed with errors. Words and whole phrases are repeated twice in succession or completely omitted, while the entire manuscript has had the text mutilated by some person or persons who ran over every letter with a pen making exact identification of many of the characters impossible...."
"...One of the manuscripts that make up the Minority Text is the Vaticanus. The Vaticanus was found in 1481 in the Vatican library. The other manuscript is the Sinaiticus. The Sinaiticus was found in 1844 in a trash pile at Saint Catherine's monastery, and rescued from a long (and well-deserved) obscurity. It has a great number of omissions and has many words and phrases marked out and re-written...."
http://www.ecclesia.org...