What's the basis?

I saw this:

1. Tetanus-not contagious 2. Hpv-transmitted through sex 3. Hep B-transmitted through sex & drugs 4. Diphtheria-0 cases in the US 5. Measles* 6. Mumps* 7. Rubella* 8. Chickenpox* * Historically a minor childhood disease in healthy children.

What’s the basis for mandating these?

Note: Mumps might be an exception because if developed in adolescence can cause sterility.

Helping another student

In a yeshiva in Bnei Brak the members of the hanhola were frustrated with the resistance of advanced talmidim who were asked to learn and help the newer talmidim but declined, claiming it was 'Bitul Torah'. The members of the yeshiva‎ ‎administration went to ask the Chazon Ish for advice. The Chazon Ish, zt'l asked to speak to them. He then asked them, "Do you put on tefilin every day"? They enthusiastically responded "Of course we do"!

Then the Chazon Ish continued "But why? Doesn't it take away time from learning"? You put on teffilin because it is a Torah mitzvah, so the Chazon Ish continued "Helping another student in his learning is no less of a mitzvah than putting on teffilin"

3 Oaths - Not Aggadata

There's a myth going round town that very few gadolim viewed the Three Oaths which prohibited immigration en masse and conquest of Eretz Yisroel pre-Mosiach as binding halacha. Many people think that only the Satmar Rav said this, as if that wouldn't be substantial in itself. 

However, even according to leading figures at YU, many if not most gadolim viewed the oaths as halacha.

Rabbi J. David Bleich, a Rosh Yeshiva and prominent scholar at Yeshiva University, writes, 

“Elsewhere in Contemporary Halakhic Problems, Vol. I, I have presented a fairly comprehensive list of the various views concerning the nature of the oath, ‘shelo ya’alu be-chomah.’ The view that ‘the oath was simply aggadic and never binding’ is but one view among many and is distinctly a minority view.”  

Rabbi J. David Bleich, “Withdrawal from Liberated Territories as a Viable Halakhic Option,” Journal of Halacha and Contemporary Society, Vol. XVIII, Succot 5750, Fall 1989, p. 107.

Rabbi Hershel Schachter, another prominent figure in the Religious Zionist world, writes, 

“In expounding the verse ‘I have made you swear, O daughter of Jerusalem,’ the Gemara relates that the Almighty administered three oaths on the Jewish people. The time and nature of these oaths are not clear, but one of them entailed a commitment on the part of the Jews not to return and conquer Israel by force. Many Gedolim in Europe took this to forbid any attempt at reestablishing the State of Israel before Messianic times.” 

(Rabbi Hershel Schachter, “The Mitzvah of Yishuv Eretz Yisrael,” Journal of Halacha and Contemporary Society, Number VIII, p. 27.)

Rabbis Bleich and Schachter are arguably the most prominent scholars associated with YU and the Modern Orthodox world. 

Rabbi Yaakov Forchheimer shlita

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Rabbi Yaakov Forchheimer, posek at the Lakewood Yeshiva, is a Yekke who was raised in Washington Heights.

Mizmor Shir Lyom Hashabas Lewandowski. 1985 http://breuers2gether.com/

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