The Central Drugs Standard Control Organization (CDSCO) has rejected Indian Immunologicals Ltd’s request to test the six-in-one vaccine on humans, according to two officials and documents seen by Mint. The regulator fears the unintended release of the polio strain could revive the crippling disease that was banished from the country 14 years ago.
Documents reviewed by Mint showed that the IIL product uses antigens (attenuated viruses) from Sinovac, China’s largest private sector vaccine maker. Many vaccines use weakened viruses that force the body to make antibodies to defend against the real threat when it arrives. The difference here, however, is that the Sinovac antigen uses a Chinese variant of the virus that has never been used in any polio vaccine in India.
China’s Sinovac has sold 10 million doses of Sabin’s inactivated poliovirus vaccine (sIPV) in China, Thailand and Pakistan, the only three countries where it is used.
A green light for IIL and subsequent approvals would pave the way for the commercial launch of the vaccine in India, where polio vaccine is administered to tens of millions of infants and children each year. The rejection of the study’s proposal underscores the priority of public health and biosecurity, even as vaccine manufacturers push for new-generation combination injections in the vast market.
What worried the committee
According to documents seen by Mint, the CDSCO Expert Commission (SEC) on Vaccines has identified potential “safety and containment issues” regarding the Chinese antigen. At its Dec. 22 meeting, the committee found that IIL failed to submit data from “post-marketing surveillance,” including actual safety reports from countries where its doses were distributed. The committee noted that no study was available in any population on this specific hexavalent vaccine containing antigens of Chinese origin.
In addition, Sinovac did not have approval under the WHO’s Poliovirus Containment Certification Scheme (CCS), the committee added, concluding that “at this stage no informed decision can be made” to continue the trials. The WHO scheme provides assurance through rigorous biosafety, biosecurity and surveillance mechanisms.
CDSCO reminded IIL, a subsidiary of the National Dairy Development Board (NDDB), that Southeast Asia, including India, has been certified polio-free since 2014.
What Indian Immunologicals says
However, according to IIL, Sinovac is not new to India and has been bulk selling hepatitis A vaccine to an Indian company for almost seven years. Sinovac’s tie to the polio vaccine was based on “its excellent safety profile,” CEO Dr. K. Anand Kumar in an interview.
“Unlike the Salk IPV, which comes from a wild virus, the Sabin version uses a weakened form of the virus that is then inactivated, making it much safer to contain. Also, these are not ‘Chinese strains’ in the proprietary sense. These strains are distributed and routed through the WHO and the Netherlands Institute. In fact, the S Drinovac and Kumar IPV vaccine is already manufactured by the WHO. over the phone.
Worries about escaping from the lab
“Laboratory escape” is another nightmare for public health officials.
According to an expert panel, polio viruses for vaccine research and production must be safely stored in certified “polio core facilities”. It warned that ingestion was the natural route of transmission and even fully vaccinated factory workers could become infected and spread the live virus into the community through sewage, contaminated skin or air.
Dr. Kumar said his company would meet all the requirements.
“We have already successfully completed all pre-clinical toxicology studies and produced initial batches. While the SEC required specific restriction certificates from Sinovac, we have already communicated this to our partners to expedite the process. We will commit to and comply with all requirements set forth by the SEC,” said Dr. Kumar Mint.
Queries emailed to the Health and Family Welfare spokesperson as well as the Ministries of External Affairs and DCGI on January 15 and the Chinese Embassy in New Delhi and Sinova on January 16 remained unanswered. Inquiries emailed to the Serum Institute, GSK and Sanofi on January 15 were also not answered.
What health experts think
Preventing the reintroduction of the polio virus is a matter of national security, health experts said. Even when the viruses are weakened, they can “revert” into more dangerous, virulent forms, leading to outbreaks of circulating vaccine-derived polioviruses, they said.
Dr. Naveen Thacker, executive director of the International Pediatric Association (IPA), a global non-governmental professional organization representing more than 1 million specialists, said: “The proposal to use the Sabin strain, the same strain used in the oral polio vaccine (OPV), presents a unique challenge.” If there is an accidental leak from the lab during testing and the virus revives, it will be difficult to maintain India’s polio-free status, said Dr. Thacker. “Conducting such trials is simply not possible without robust WHO-certified facilities to manage the storage and handling of materials.
He said the missing post-marketing surveillance (PMS) data was a red flag. “What happened after the launch? This data is only from Pakistan and China; it’s not enough, so we can’t risk it,” said Dr. Thacker. “India does not currently face a shortage that would justify taking such a risk. We now have sufficient supply of traditional IPV. That was a problem a few years ago, but now supply is not a problem.”
Polio has different strains, and wild polio may still exist in some countries, said Dr. Sanjeev Bagai, senior consultant in pediatrics and chairman of Nephron Clinics, New Delhi.
“Any additional polio strain in six-in-one vaccines must comply with all guidelines and regulations. The strain must have clinical real-world validation data from phased trials that document the threshold of vaccine efficacy. If Chinese data is missing, then it is best not to use this vaccine,” he said, adding that there is no need to compromise India’s infectious disease surveillance. “The worst thing is to bring a neurotropic unverifiable burden to Indian shores.”
Pentavalent, hexavalent vaccines
Newborns in India are usually given a single shot pentavalent vaccine that protects against five diseases – diphtheria, whooping cough, tetanus, hepatitis B and Haemophilus influenzae type b. In addition, polio vaccines are given as oral drops.
However, companies such as Serum Institute of India, Panacea Biotec, GSK and Sanofi manufacture and sell hexavalent vaccines that also protect against polio. However, hexavalent vaccines are not part of the government’s universal immunization plan. Also, none of the existing hexavalent vaccines use the Chinese antigen.
A spokesman for Panacea Biotec, which makes EasySix, a hexavalent vaccine, said: “The SEC result signals that the Indian regulator is in line with the WHO Global Action Plan, so certification of poliovirus equipment is not up for negotiation. Manufacturers must demonstrate thorough alignment with the containment framework, proactively engage with national containment authorities and share broad international safety expectations for vaccine biosafety.”
“Certification for protection against poliovirus is a non-negotiable strategic biosecurity imperative. Protecting India’s hard-won polio-free status requires absolute assurance that no poliovirus can escape from manufacturing facilities. This GAP-III WHO certification provides that assurance through rigorous surveillance and reinforces confidence in our Panaceaecosystem,” said Panaceaec.
A logical step?
According to Dr. IIL’s Kumara transition is a logical step for Indian public health. “The new combination offers significant benefits to a nation with an annual birth cohort of 27 million by reducing the burden on parents and simplifying the massive logistics of procuring vaccines,” he said.
Although post-market surveillance data is being sought, it should be noted that the Sabin IPV program is relatively new globally, with licenses currently in China and sales in markets such as Pakistan, he said.
“Ultimately, bringing more players into this space is critical to cost competitiveness. Our program is designed to support both the private single-use vial market and the government’s universal immunization program with multi-dose formats should they decide to move to hexavalent protocols,” Kumar reasoned.
