As a rule, patent applications are generally published after the end of the 18-month period of time from the filing date (or from the priority date, if claimed). This makes a patent application, once filed, known just to its applicant and a small group of examiners, and thus, somehow becomes “secret” to the public, until it is published. Eighteen months is quite a long period of time, and many other patent applications may be filed therein. Hence, an interesting question is whether such a “secret” prior art is cited against later-filed applications.

Answers vary among IP offices around the world. Some accept secret prior arts as citations, the others do not. Viewpoints also differentiate regarding scope of citation would secret prior arts be accepted; some accept them for both novelty and inventive step evaluation, some for novelty only. Also, consensus has not been reached regarding the so-called “self-collision”, which means citation of a secret prior art against later-filed applications of that very applicant.

Under the current IP laws, Vietnam falls into the smaller group of countries that do not accept secret prior arts as citations against later-filed applications, regardless by third parties or itself. This practice is mainly caused by the notion adopted by Vietnam that citations are those known to the public, that means a prior art must have been published before being considered a citation. However, this viewpoint leads to an undesirable outcome of the so-called “double patenting”, which is resulted from granting a patent for an already-known invention, just because the prior arts, which are still in the period of 18-month secrecy at the time of filing the later-filed applications, are not accepted as citations.

To avoid the double patenting, Vietnam seeks help from Article 90 of its IP Law, which literally provides for the “first-to-file” principle. In combination with the “claim only” doctrine, the IP Vietnam often make comparison of claim sets in order to reject the later-filed application, should any identicalness between the two sets of claims be found. This arrangement works in some cases. But it does not solve the issue completely, especially in case although the two patents are for the same subject matter with the same scope of disclosure, the sets of claims are, for some reasons, not exactly the same. Also, the issue of novelty v. inventive step and “self-collision” is still remained questionable.

Recently, Vietnam has made big change in this regard by revising Article 60.1, the IP Law, concerning patent novelty with the following wording:  “An invention in a patent application with a later filing date or priority date is considered having lost its novelty if it is disclosed in another patent application with earlier filing date or priority date but published on or after the filing date or priority date of such a later-filed patent application”.

This revision will, once issued and takes effect, serve as a ground for entering applications, which are earlier-filed but not-yet-published before the filing date (or priority date) of the later-filed applications, into the state of the art to refuse those later-filed applications with the same subject matters. In other words, secret prior arts will be taken into account during the examination of novelty of inventions. This can prevent granting patent for an already-known invention, and as such, help avoid the issue of double patenting. Also, it appears that with such revision, Vietnam will accept the secret prior arts as citations for novelty assessment only, not inventive step.

This proposed revision is still, however, ambiguous in some points. First, the “self-collision” issue has not cleared yet. With the wording “another patent application“, one cannot determine whether the earlier-filed application is owned by another applicant or not. That is, whether the secret prior arts can have effect against just third-party applications or even applications of the same applicant.

Second, if the earlier-filed application is withdrawn prior to being published, would the earlier application be cited as a secret prior art? A utility model application in Vietnam can be cited as secret prior art against a later-filed application? Can an application filed in a country other than Vietnam, or a PCT application not designating Vietnam be used as secret prior art?

For answers to these questions, we need to await the final version of Article 60.1, the IP Law, once it is released, and more importantly, look into the change in practice of the IP Vietnam after the revised IP Law is issued and takes effect, expectedly in 2022