PopVax is an Indian full-stack biotech building first-in-class and best-in-class vaccines and cancer immunotherapies using machine learning-driven protein design and relentless empiricism. We design, develop, and manufacture our own RNA medicines end-to-end because we believe great pharmaceutical science can only flourish in tight feedback loops that iterate rapidly. PopVax's experimental work and clinical dose production is based at the RNA Foundry, our integrated R&D and GMP-capable clinical dose production facility in Hyderabad.

PopVax's north star is our goal of developing novel vaccines and therapeutics over the next decade with the cumulative ability to save 1 million lives each year – the Million Lives Mission. To that end, we are developing first-in-class vaccines against Hepatitis C, Strep A, and adult pulmonary TB; broadly-protective best-in-class vaccines against COVID-19, influenza, malaria, and HPV; and precision immunotherapies against hard-to-treat solid tumours such as liver cancer and pancreatic cancer. Beyond existing diseases, we are leveraging our high-speed platform to build rapid-response biosecurity capabilities against engineered de novo pathogens.

Our mission is funded by Vitalik Buterin's Balvi Fund, the Gates Foundation, the US Biomedical Advanced Research and Development Authority (BARDA), Renaissance Philanthropy, and Good Ventures, with individual investments from Enveda founder Viswa Colluru and Tesla self-driving AI pioneer Dhaval Shroff. Our first program, an open-source broadly-protective COVID-19 vaccine, will begin a Phase I clinical trial in Australia in mid-2026. This is just the start – we intend to advance 6+ novel vaccine and immunotherapy programs into human clinical trials over the next three years, decisively demonstrating that world-class biotech R&D is possible in India.

No matter the job title, each person's role at PopVax is ultimately about helping bring safe, effective new medicines that represent a step-change over the current standard-of-care to the people who need them, as quickly as possible. If you are looking for a place where the ambition is high, the learning curve is steep, and the work matters to billions, you'll feel at home here.

If you're excited by the idea of advancing scientific, clinical, and regulatory frontiers of vaccines and immunotherapies, spending each day developing medicines with the potential to save millions of lives, and building a generational global pharmaceutical company in India along the way – join us!

About the role

A targeted radiopharmaceutical works or fails on a few numbers: how tightly the ligand binds, how many target sites there are per cell, how much of the signal is specific, and how fast the ligand comes off. Dosimetry, therapeutic index and candidate selection all sit on top of those numbers. We are looking for someone experienced with radioligand binding assays to work in a hot lab and test our candidates to find these numbers.

What you'll do

• Develop and run our radiolabelling methods. Chelator loading, buffer and pH selection, molar activity, temperature and time, apparent specific activity, post-labelling purification on C18 or size-exclusion cartridges. You'll take a method from cold surrogate work (nat-Ga, nat-Lu) through to a reproducible hot procedure that gives us the radiochemical purity and molar activity we need, batch after batch, and you'll write it down properly so it survives you.

• Own radiochemical QC and dose release. Radio-TLC and radio-HPLC for radiochemical purity, radionuclidic purity and identity, half-life verification, pH, endotoxin, sterility, residual solvent, free-isotope content, apyrogenicity. You'll build the release panel, qualify the methods, set the specifications with justification, and be the person who says a dose is fit to administer to a human being — or that it isn't.

• Run the interface with our partner facility. You'll be PopVax's person on their site: scheduling generator elutions and synthesis runs, agreeing on procedures with their radiopharmacy and nuclear medicine staff, qualifying their equipment for our use, resolving the inevitable mismatches between how they've always done it and what our protocol requires. This takes technical credibility and it takes tact, often in the same conversation.

• Handle the regulatory and licensing work for radioisotopes. AERB licensing and e-LORA filings, isotope procurement and transport, source inventory and accounting, waste decay storage and disposal records, and the radiopharmacy sections of clinical trial applications and ethics committee submissions. Regulators ask hard questions about radiation dosimetry and dose justification; you'll be the one with the answers.

• Own radiation safety — yours and everyone else's. ALARA in practice, not on a poster: shielding design, remote handling, contamination monitoring and surveys, personnel dosimetry, spill response, training for colleagues who don't work with isotopes daily, and the discipline to stop a run when something isn't right. You will set the standard that everyone else at PopVax follows, and you will be trusted to enforce it upward as readily as downward.

• Close the loop with the protein chemistry. Labelling behaviour is a readout on the molecule. Poor chelator occupancy, transchelation, metal contamination from IMAC, conjugate heterogeneity, radiolysis at high activity — these are conjugation and purification problems that show up first in your hands. You'll work directly with the protein engineering, analytical, and CMC teams so that what you learn in the hot lab changes how the next batch is made, rather than sitting in a deviation report.

• Build the dosimetry and preclinical imaging picture. Biodistribution studies, PET/SPECT imaging in animal models, organ dose estimates, and the human dosimetry calculations that set the starting activity in a first-in-human study. You'll do this alongside our preclinical and clinical teams, and your numbers will be in the protocol.

Who you are

• You are safety-minded, for yourself and for everyone around you. This is not a line we put in every job description. Radiation safety is a discipline that protects people who aren't in the room and can't see the hazard, and it only works when somebody holds the standard without being asked. You survey when nobody is watching. You speak up when a colleague is about to do something careless, and you do it in a way that they hear, because being right about safety is useless if nobody listens to you.

• You communicate well, across organisations. Much of this job is conducted at somebody else's facility, under somebody else's SOPs, with staff who don't report to you and have their own clinical workload. You'll also write — methods, specifications, deviation investigations, regulatory sections — and be read by regulators, ethics committees, and clinicians. You can explain a radiochemical purity failure to a nuclear medicine physician, a physicist, and a protein engineer, and each of them will come away with the right picture.

• You are a chemist, not just an operator. You can run somebody else's labelling kit, but you can also work out why it's failing. You understand chelator chemistry, metal coordination, radiolysis, the effect of trace metals, and what a specific activity number actually constrains. When a method doesn't exist for the molecule in front of you, you develop one.

• You are comfortable being the only one. You'll be PopVax's first and, for a while, only radiochemist. Nobody will hand you a protocol, a qualified method, or a fully built hot lab. That prospect should read as an opportunity rather than a warning

• Willing to stretch hours and work late evenings, when radioisotope is most available because of generator capacity.

Qualifications

• MSc, MTech, or PhD in Radiochemistry, Radiopharmacy, Nuclear Medicine Technology, Nuclear or Inorganic Chemistry, Medicinal Chemistry, or a related field — or equivalent hands-on experience demonstrating comparable depth.

• Minimum one year of hands-on experience working with radioisotopes in a nuclear medicine setting — hospital radiopharmacy, PET/cyclotron centre, or radiopharmaceutical production facility. This is a hard requirement. We are not able to train someone into first-time isotope handling on a clinical programme.

• Practical experience with diagnostic and/or therapeutic radionuclides: ⁶⁸Ga, ¹⁸F, ⁹⁹ᵐTc, ¹⁷⁷Lu, ¹³¹I, or similar. Generator elution, dispensing, dose calibration, and aseptic handling of radioactive material.

• Working knowledge of radiochemical QC: radio-TLC, radio-HPLC, dose calibrators, gamma spectroscopy, and the interpretation of radionuclidic and radiochemical purity data.

• Sound understanding of radiation protection principles and Indian radiation regulation — AERB requirements, licensing, source accounting, and waste management. RSO certification (Level II or above) is a strong advantage; if you don't hold it, you should be eligible and willing to obtain it.

• Excellent written and spoken communication, with demonstrated ability to work effectively inside another organisation's facility and with clinical staff.

• Willingness to be based in Hyderabad and to travel regularly to our partner facility.