On the recent Delhi High Court judgement concerning a genetically modified salmonella bacteria, Prashant Reddy T writes on how the Court missed the boat in laying down the law on some important issues for the biotech industry concerning the patentability of microorganisms and disclosure requirements for such inventions. Prashant Reddy T is one of our most prolific bloggers (his posts can be accessed here). He is also the co-author of two books- “Create, Copy, Disrupt: India’s Intellectual Property Dilemmas” (OUP, 2017) and “The Truth Pill: The Myth of Drug Regulation in India” (Simon and Schuster India, 2022).

Delhi High Court Stirs the Pot for Biotech Patent Applicants in India
By Prashant Reddy T
Recently on 21 February 2025 the Delhi High Court delivered a judgment upholding the Patent Office’s rejection of a patent application filed by the University of California seeking a patent for a vaccine for livestock. This appeal provided the High Court a rare opportunity to lay down the law on some important issues for the biotech industry and unfortunately, in my opinion, the Court missed the boat.
About the Invention
The dispute patent application no: 201717005699 was filed with the patent office on 17 February 2017 for a “Vaccine for livestock production systems”. In this application the University of California sought a patent for a genetically modified salmonella bacteria which could be used as a candidate for a ‘live-attenuated vaccine’. The patent applicant claimed to have solved specific problems with existing vaccines for salmonella by introducing a “loss of function” mutation to specific genes in the salmonella bacteria causing them to lose their virulence. This genetically modified salmonella bacteria could still be used as a vaccine candidate to elicit a response from the immune system of animals thereby helping to vaccinate them against future infections. The key advantage, as claimed by the inventors over other ‘live-attenuated vaccines’, is that by supressing the specific genes that were the cause of the bacteria’s virulence, they were able to create a vaccine candidate which exhibited improved vaccine safety “in the subject to be immunised and in the environment”.
The original claim 1 read as follows (subsequently amended): “A Salmonella microorganism, wherein said microorganism comprises a loss of function mutation in the dam gene and at least one further loss of function mutation in a gene selected from the group consisting of: sifA, spvB and mgtC.”
The Rejection Order
The Controller of the Patent Office rejected the patent application on 14 July 2022 on two grounds: first the lack of patentable subject matter as per Section 3(c) and second, failure to meet specific enabling disclosure requirements in Section 10 – this includes lack of adequate disclosure on how to work the invention and failure to deposit a sample of the bacteria. The decision of the Controller under Section 15 can be accessed here (pdf). The Patent Applicant filed an appeal before the Delhi High Court in 2022 resulting in the judgment which is the subject of this piece.
The Section 3 Analysis – (c) or (j)?
As most readers may be aware, Section 3 of the Patent Act provides a list of subject matter for which a patent cannot be claimed as inventions – this analysis under Section 3 is separate from the patent eligibility analysis which evaluates whether an invention is novel, inventive and capable of industrial application. For example, Section 3(c) renders unpatentable the discovery of any living substance occurring in nature.
In this case, in the Examination Report (pdf), the Controller objected to multiple claims on the grounds of Section 3(c) since according to the Controller these claims covered bacteria already found in nature.
In its response (pdf) the patent applicant argued that the claimed mutations were not naturally occurring and were the result of substantial human intervention and hence not within the purview of Section 3(c). In the final order under Section 15 rejecting the patent application, the patent controller does not engage with the reasoning that the claimed mutations had been caused by “human intervention” and instead, simply concludes that the claims are broad enough to cover all types of salmonella found in nature. On appeal, the Delhi High Court upheld the Patent Office’s decision on the point of Section 3(c), concluding that the claims were defined broadly to cover even “naturally occurring loss-of-function variants of Salmonella”.
I cannot wrap my head around the above conclusion because the revised Claim 1 filed by the patent applicant, clearly used the phrase “recombinant Salmonella microorganism”. The phrase “recombinant” generally means genetic substances made in the laboratory through human intervention. If Claim 1 uses the phrase “recombinant” it means that the invention being claimed is limited to genetic material manipulated by humans and not material found in nature.
But the larger problem with the Patent Office’s order and the Delhi High Court’s judgment is the conclusion that Section 3(c) even applied to the facts of this case. I say this because micro-organisms are completely out of the purview of Section 3. This exception was introduced into Section 3(j) as a result of India’s obligations under Article 27 of the TRIPs. While allowing contracting parties to exclude “plants and animals” from the sphere of patentable subject matter, Article 27 clearly required “micro-organisms” to be considered patentable subject matter. As a result, The Patent (Amendment) Act, 2005 introduced a “carve out” in Section 3(j) for micro-organisms. When this bill was debated in Parliament in 2005, there was immense opposition to the idea of patenting microorganisms. The then Commerce Minister Kamal Nath bought some time by promising Parliament that he would constitute an expert committee to study whether it would be TRIPs compatible to exclude microorganisms from the scope of the Patents Act. In the meanwhile, the vote on the bill went ahead in Parliament and the carveout for microorganisms in Section 3(j) became law. Later, the expert committee headed by Dr. Mashelkar concluded that India could not exclude microorganisms from the purview of Section 3 and so the carveout for microorganisms in Section 3(j) remained untouched.
Thus, if a patent application is claiming a microorganism, there is no requirement for a Section 3 analysis due to the carve out in Section 3(j) for microorganisms. Instead, the Patent Office should proceed directly to an analysis of whether the claimed micro-organism is novel, inventive and capable of industrial application. A naturally occurring microorganism would not qualify for a patent because it is not novel. To be fair to the Patent Controller and the Delhi High Court, I am not sure if this argument was made by the lawyers representing University of California.
The Enabling Disclosure Requirement in Section 10
The second part of this judgment, which is likely to torpedo many a biotech patent application in India is the manner in which the Patent Office and the Delhi High Court has interpreted the disclosure requirements in Section 10.
The simple logic of a disclosure requirement in patent law is that the patentee should be required to disclose to the world enough information for others to be able to work the invention. Such disclosures are also important to ensure that the rest of the world are aware of the boundaries of the invention, so that they can continue research in adjoining areas not covered by the patent. For some technologies, meeting the disclosure requirement will be relatively simple but biotech is not one of those technologies.
Indian law has some specific requirements for inventions related to biological material, such as a deposit requirement. However, Section 10(4) requires the deposit of biological material only if the patent specification does not fully describe the invention and disclose the best method by which they may work the invention and if such material is “not available to the public”.
The Patent Controller concluded that the patent applicant had failed to meet the Section 10(4) disclosure requirement on both counts i.e. the applicant failed to make an enabling disclosure which would allow a person skilled in the art to work the claimed invention and also that it failed to meet the obligation to deposit the biological material per the Budapest Treaty. Now the first part of the Controller’s assertion may well be true but this is a question of fact and the evidentiary basis for the Patent Controller’s arriving at this conclusion is non-existent. Reading the order of the Controller under Section 15 does not provide us with any insight on the evidentiary basis of the final conclusion.
Ideally, the Examination Report which forms the basis of the Section 15 hearing should contain a clearly articulated objection with some evidentiary basis on why the Controller is of the opinion that the specification fails to make adequate disclosures. This should include some evidence on the state of the art and why a skilled person will not be able to work the invention given the existing disclosures in the specification. For example, the Patent Controller could cite academic literature while come to this conclusion. The patent applicant should then be allowed to counter the Controller in the hearing under Section 15. This is important because the state of the art and the skilled person’s capabilities changes with time. For example, modifying specific genes of a bacteria may have been difficult back in 1990 in the early days of the biotech revolution but it has become easier in 2025 given the broader dissemination of biotechnology across the world.
Similarly, reasoning has to be provided by the Patent Office, while concluding that the deposit requirement under the Budapest treatment must be met. If salmonella is publicly available and it is possible for a person skilled in the art to identify and modify the specific genes as claimed in this patent application, should there continue to be a requirement to deposit a sample of the biological material? As per Section 10, the answer is in the negative.
Either way, the Patent Office has to provide far better reasoning with some evidentiary basis. The Patent Controller’s personal anecdotal opinion cannot be the basis of rejecting patent applications. It is also important for the Patent Controller to be procedurally fair in how it comes to this conclusion i.e. the examination report must contain the detailed objection, including the evidentiary basis so as to allow the patent applicant an opportunity to present a defence. In this case, the examination report had raised a vague objection to Claim 6 claiming that a sufficient disclosure had not been made and then the final order under Section 15 rejects the application on the grounds that the first five claims were not enabled, meaning that the patent applicant was essentially ambushed at the S. 15 hearing. This should not be happening at the Patent Office.
On appeal, the Delhi High Court did no better. Referring to a specific paragraph of the patent specification, the court concluded that the patent specification does “not disclose the inventive contribution fully” but at no point does the High Court provide the evidentiary basis for arriving at this conclusion. If the Patent Controller’s order does not contain the evidentiary basis, the High Court should remand the case back to the Patent Office for an evidentiary finding on the issue of enablement.
Before I conclude I should mention that since the transcripts of oral arguments are not publicly available, I do not know what exactly was argued by the patent applicant before the Delhi High Court and if these issues were not raised before the High Court, it cannot be blamed for the judgment that followed.

could this part from the judgement regarding section 10(4) (a) objecion be considered as evidence for their inference:
“17.In my considered view, a detailed examination of the complete specification, clearly reveals that the detailed description refers only to disclosure and example of deletion mutation of S. Typhimurium dam vaccine candidates. The relevant portion from the example (complete specification, page 18) is reproduced here below:
“7.2. Construction of S. Typhimurium dam vaccine candidates
comprising an additional attenuating mutation
S. Typhimurium UK-1 Adam was constructed by introducing an inframe
300 bp deletion of defined dam sequence, termed damA232 [ 19],
using standard genetic protocols [20]. The resultant S. Typhimurium
UK-1 damA232 strain (MT31 34) was shown to be sensitive to the purine
analog, 2-aminopurine (2-AP), which is toxic to strains lacking a nonfunctional
DNA adenine methylase [21 , 22], and was used as the
parental Salmonella dam vaccine strain for all studies. Secondary
virulence-attenuating deletion mutations were introduced into the
parental S. TyphimuriumUK-1 damA232 strain utilising suicide vector
pCVD442 as described [20], resulting in the construction of in-frame
deletions of defined coding sequence in the following targeted genes:
dam aroA (MT31 38; 1056 bp deletion); dam htrA (MT3142; 1341 bp
deletion); dam mgtC (MT31 46; 606 bp deletion); dam sifA (MT31 50;
807 bp deletion); dam spiC (MT31 54; 306 bp deletion); dam spvB
(MT31 58; 1563 bp deletion); and dam ssa\/ (MT31 62; 1959 bp
deletion). The resultant genetic constructs were confirmed by PCR
using primers that flank the deleted sequences.”
[Emphasis Supplied]
18. Hence, the above-extracted working example and detailed description, which are limited to deletion mutations, do not disclose the inventive contribution fully that also covers insertion and substitution. Accordingly, in my considered view, the lack of specific disclosures in respect of insertion and substitution mutations results in an insufficiency of disclosure, which renders the subject patent application non-compliant with the mandatory requirements under Section 10(4)(a) of the Act.”.
Regarding section 3(c) objection: if the mutations remain undisclosed, the endogenous mutations that are possible to be occuring in nature, how could that be claimed? could mere usage of “Recombinant”” comes for the help?
A very good analysis and comment, Prashant.
I think if the patent was granted and
1) If there is even a remote chance that the claimed loss of function mutations can occur in nature without human intervention (Sec 3c is applicable then) and someone isolates that mutated loss of function strain and use it for commercial purposes would the applicant be able to file infringement suit?
2) Submitting at least one sample u/s 10(4) would have added much weight to the application.