Eight months ago, an incident occurred that struck a severe blow to confidence in India’s vaccine industry. Thirty lakh batches of polio vaccine came under suspicion in October 2018, after samples showed that these batches contained type 2 live poliovirus, a strain that was declared eradicated by the World Health Organization in 2015.
The apparently-contaminated vaccines presented a very real threat that Indian children could be exposed to a type of polio that has not existed in the wild since the turn of the century. Despite this, media coverage of the event has largely fallen silent, save one new piece of information: the Modi government has launched a prosecution case against Ghaziabad-based vaccine maker, Bio-Med Pvt. Ltd.
Oral polio vaccines and polio cases
India still makes use of oral polio vaccines (OPVs) as part of its Universal Immunisation Programme (UIP). Though OPVs have played a major role in the global polio campaign, the major risk they hold is the potential for vaccine-derived polio (cVDPV). The threat comes from the use of live — but weakened — polio strains in the OPV. Vaccinated individuals excrete some of the live virus from the OPV into the environment. Where immunisation levels are high, cVDPV is a far lower risk. However, lower rates of immunisation expose unvaccinated individuals to the risk of cVDPV.
OPVs all used to contain type-2 wild-type polio. But this strain of the virus has not been seen in the wild since 1999. As per World Health Organization (WHO) guidelines, the type-2 strain was removed from OPVs worldwide in 2016 in order to reduce the potential for cVDPV to occur. Pharma companies and governments were ordered to destroy any remaining supplies. Type-2 was the first strain of polio to be eradicated. It also has the highest chance of the three strains to induce vaccine-derived polio.
Of course, one risk of removing one type of the virus is that no-one will have immunity to it in the future. If it is extinct and no longer used in any live vaccine, that should not cause a problem. As a backup, India has had in place routine vaccination using one dose of the inactivated polio vaccine (IPV) since 2015. This vaccine runs no risk of cVDPV due to the use of inactivated — or dead — viral particles, but it does protect against all three types. The future strategy for polio eradication globally is to switch from OPV usage to exclusive IPV use. This would eliminate the risk of any cVDPV altogether.
Despite polio being eradicated in India, it is one of the most vulnerable countries for a potential new outbreak. There were under 40 wild-type polio cases in the world last year, due to sustained efforts globally. However, India is next to Pakistan, one of only three polio-endemic nations in the world, alongside Afghanistan and Nigeria. The anti-polio drive is in a precarious position in Pakistan today owing to the spread of anti-vaccine misinformation in the country and attacks on health workers.
The legal case
The prosecution case against Bio-Med has been brought by the Central Drugs Standard Control Organisation (CDSCO) — the country’s apex drug regulation body, which operates under the Union Ministry of Health and Family Welfare. The prosecution’s case cites a breach of the Drugs and Cosmetics Act, 1940, claiming the company is the cause of a major health scare. In addition to charges against the company itself, the CDSCO will also seek to prosecute Bio-Med’s 81-year-old founder and managing director, Sarayu Garg.
A government investigation was launched into the company soon after it was revealed that batches of the vaccines had apparently been contaminated. Though the company initially protested, it was confirmed in the months following the initial finding that several other batches also contained type 2 virus. This led to the company being denied their right to continue producing and selling other products.
The investigation was then directed towards PTO Bio Farma, the Indonesian pharmaceutical company which supplied the starting components of the vaccines to Bio-Med. Bio Farma were subsequently blamed by the Indian company. An inspection team was dispatched from India to the company to inspect the facilities. However, health inspectors did not find any instances of type 2 virus in the source material when they investigated, and focus shifted back to Bio-Med.
Experts contacted by HII say that the most likely explanation is that Bio-Med failed to destroy either vials or raw materials that it had prior to May 2016. After the global deadline for eliminating type 2 virus from OPV, it was illegal to have or sell these. Either in error or to maximise profits, it is possible that Bio-Med reintroduced product from this period back into the distribution chain in 2018.
Media coverage: a double-edged sword?
Shortly after the announcement of the unsafe products, the story dropped from the news cycle. This is not uncommon: the media quickly moves on to other matters and so even potential public health crises are often rapidly forgotten. The underwhelming coverage, however, did little to raise awareness of the dangers the OPV could have posed.
In order to address concerns of growing anti-vaccine sentiment, it is the duty of both the vaccine producers, as well as the Indian government, to ensure stringent quality standards. If a repeat of this incident were to occur — particularly a case where the vaccines made it into circulation — a wave of individuals may begin to turn their backs on the very vaccines that rid India of the poliovirus in the first instance.
Further setbacks to India’s polio immunisation?
More hurdles are presenting themselves to India’s immunisation campaign against polio. The Central Drugs Laboratory in Kasauli, Himachal Pradesh, has declared sixteen batches — equating to 30,000 vials — of OPV manufactured by Bibcol (Bharat Immunological and Biologicals Corporation Limited) as ‘substandard’.
One vial is the equivalent of around twenty doses, meaning a further deficit of 600,000 doses in addition to those lost to the contamination scandal of last year. India is in need of around ninety million doses overall to provide full coverage during the national immunisation programme set to take place in June.
While 600,000 may seem like a drop in the ocean compared to this amount, it creates a shortage. The deficit will need to be picked up by other companies in order to bring about enough doses to fulfill the requirement for full coverage.
The necessity of ensuring every child is protected against the virus is ever more apparent after the near-crisis of the faulty batches last year. The detection and classification of the batches as substandard does, however, indicate that greater measures are likely being put in place to ensure quality is maintained when producing the vaccines.
India’s campaign against polio ranks among its greatest public health success stories. For a country with such a vast population and geographic diversity to host a vaccination campaign on such a scale is remarkable. Continuation of vaccination campaigns into the future is an essential component of ensuring the country remains polio-free.