He works at Japan Vaccine Company. (Google translate translates that sentence as: Kare wa Nihon wakuchin kaisha de hataraite imasu. 彼は日本ワクチン会社で働いています。) I am *not* sure that the company does *not* have a website.So you do not know whether your friend is still working there? Are you sure the company has no website?
Maybe the paper was published in 2018, I forget. Also, getting papers reviewed and published takes time, so maybe the paper was published after the company was dissolved. I met Masahiro Eda and his wife, Naomi, at work. We became friends. Masahiro was a visiting scholar at the university at which I worked. After they returned to Japan, I was not a very good friend and failed to keep up correspondence. I would like very much to get in touch with them again. But it has been about 20 years, and I no longer have their correct address.Google Translate is not a reliable source for translation, especially not for the official names of corporations and the like.
The Japanese sentence above is just a literal translation of the English words and will not help you locate your friend.
I did some searching, and the only company officially named "Japan Vaccine Company" (ジャパンワクシン株式会社, not 日本ワクチン) was a joint venture between Daiichi Sankyo Pharmaceuticals and GlaxoSmithKline that was dissolved in December 2018. So he couldn't have published a report for them last year—either you've confused it with another company of a similar name, or perhaps he is still working for either Daiichi Sankyo or the Japanese office of GSK.
That said, I highly doubt a major corporation would give out the personal information of one of their employees to a random person who contacts them for non-work-related reasons. What exactly is your connection to this person and his wife? Do you have no other way of reaching him except through his employer? If your connection was a personal one, it seems there would be better ways to go about this than trying to go through his company.