What Matters in Global Health - 144

Global Polio Eradication Effort Faces Setbacks: 'The Switch' to New Vaccine Strategy Sparks Unintended Outbreaks, Calls for Urgent Re-evaluation

Something momentous happened in the history of polio eradication in April 2016: Over a period of 2 weeks, 155 countries and territories started to use a new version of Albert Sabin’s classic oral polio vaccine (OPV) that no longer protected against one of the three types of poliovirus. Type 2 virus had been eradicated by then, and the only remaining type 2 polio cases were touched off by the live virus in the vaccine itself. The thinking went that dropping the type 2 component from the vaccine would also end those cases.

But “the switch,” as this global move has become known, became “an unqualified failure,” according to an unusually blunt draft report commissioned by the Global Polio Eradication Initiative (GPEI) that is now open for public comments.

Unexpectedly, vaccine-derived poliovirus type 2 has circulated after the switch, paralysing more than 3300 children. And GPEI has spent over $1.8 billion trying to quash these outbreaks, mainly in Africa. Those numbers will undoubtedly increase until the polio program finds a way to deal with the problem it inadvertently created—and with the best intentions.

“It is about time someone publicly declared the switch a failure, given the obvious management and leadership errors,” says Kimberly Thompson , who heads Kid Risk, Inc. This non-profit has long modelled the consequences of various polio vaccine options.

The authors of the report wanted it to catch the program’s attention. “We need to recognize that these are paralyzed children in some of the hardest places in the world,” says Natalia Molodecky, PhD , a consultant for The Task Force for Global Health, Inc. “These are very real consequences of the program.” But, she adds, the switch was very difficult to get right. “This is a real-life example that we can learn from to guide future action.”

“We are trying to call a spade a spade,” says her co-author Roland Sutter, who, as the head of polio research at GPEI until 2020, was one of the architects of the switch. “I hope the report will be a wake-up call for the program,” Sutter says. “Polio eradication has been my life’s work and ambition, and I would really like to see it succeed.” He still thinks it’s doable.

What the switch was intended to do, reduce vaccine-derived type 2 cases to zero, “clearly didn’t happen,” acknowledges Aidan O'Leary O’Leary, director for polio eradication at the World Health Organization (WHO), one of six core partners in GPEI. “The [case numbers] speak for themselves. The key is what we do about it.”

OPV, made of live,? weakened polioviruses, is the most effective vaccine for eradicating polio because it induces strong immunity in the gut and spreads through the stool of immunised children, protecting even those who don’t get the vaccine drops. OPV has helped decrease polio cases by more than 99.9% since the eradication program began in 1988. The “wild” poliovirus is now cornered in Afghanistan and Pakistan, where it has paralysed four children so far this year.

But in rare instances, the weakened OPV viruses can regain their ability to paralyse and start to circulate among susceptible children, sparking new polio outbreaks in areas where vaccination rates are low. That’s why the endgame of the eradication initiative calls for stopping all use of OPV once the wild virus is gone and introducing a vaccine made of inactivated virus (IPV), which can’t revert to routine immunisation.

After wild type 2 poliovirus had been eradicated, the switch—which the report calls “the largest coordinated public health effort in history”—was like a trial run for that ultimate goal. GPEI created a stockpile of a monovalent vaccine targeting only type 2 to respond to the inevitable, but GPEI thought small, vaccine-derived type 2 outbreaks would initially occur. After a few years, the reasoning was that the world could stop worrying about type 2.

Some countries could quash type 2 outbreaks with the monovalent vaccine. But in Africa, the “worst-case scenario” quickly materialised, the draft report says: Type 2 outbreaks began raging out of control as an increasing number of children who were no longer receiving the type 2 virus in routine immunisation became susceptible to it. Between 3 and 4 years after the switch—“the point of no return,” the report says—cases jumped from 84 in seven countries to 548 in 21 countries. The number of cases has increased about 10-fold since 2015.

How could that happen? The draft report says the monovalent vaccination campaigns GPEI launched in response to outbreaks were too limited geographically, came too late, and often didn’t reach enough children. Because these outbreaks occurred in places where routine immunisation rates were low, there was no backdrop of protective immunity.

Another factor, the authors say, is the “inability or unwillingness of GPEI leadership to recognise the seriousness of the evolving problem and take corrective action.” A strategy committee with representatives from GPEI’s core partners—WHO, 联合国儿童基金会 , the U.S. Centres for Disease Control and Prevention (CDC), Rotary International , the Gates Foundation , and Gavi, the Vaccine Alliance —governs by consensus. A key example of its inaction, Molodecky says, is that the evaluation was commissioned only in August 2023, more than seven years after the switch. “Having a formal review at year three … would have enabled the program to make course corrections,” she says.

Now, the goal is to stop the ongoing outbreaks. Faster, broader responses will help, as will?a novel type 2 polio vaccine that is far less likely to spark outbreaks. New vaccines are in development. The report also calls for the broader use of IPV, which doesn’t stop transmission but prevents paralysis, in routine immunisation and outbreak control. Boosting routine immunisation in vulnerable populations is critical.

The report is “a hard read,” says John Vertefeuille, director of CDC’s global immunisation division and a member of the strategy committee that governs GPEI. But, he says, “I also think it will lead us to forging very effective paths to finish the job” of eradication.

Critical drug shortages in England are jeopardising patient health. As Community Pharmacy England reported, pharmacists frequently cannot fully dispense prescriptions, escalating patient distress, frustration, and health risks.

Drug shortages in?England?are now at such critical levels that patients are at risk of immediate harm and even death, pharmacists have warned.

The situation is so severe that pharmacists often have to issue “Owings” to patients – telling someone that only part of their prescription can be dispensed and asking them to return for the rest of it later once the pharmacist has sourced the remainder.

According to Community Pharmacy England (CPE), which published the report, hundreds of different drugs have become hard or impossible to obtain. It said widespread and often long-lasting shortages posed “immediate risks to patient health and wellbeing” and caused distress.

“The medicine supply challenges being faced by community pharmacies and their patients are beyond critical,” said Janet Morrison OBE , CPE’s chief executive. Patients with a wide range of clinical and therapeutic needs are being affected on a daily basis, and this is going far beyond inconvenience, leading to frustration, anxiety, and health issues.

Recent months have seen key medicines for the treatment of type 2 diabetes, ADHD and epilepsy becoming unavailable. Last year saw?shortages of HRT, adrenalines and antibiotics.

According to James Davies, the Royal Pharmaceutical Society ’s director for England, drug manufacturers, wholesalers and suppliers needed to collaborate more closely with ministers and the?NHS?“to ensure a more stable supply of medicines.”

CPE, which represents England’s 10,500 community pharmacies, based its findings on a survey of owners' views of 6,100 pharmacy premises and 2,000 of their staff. It found:

• 79% of pharmacy staff said that medicine shortages put patient health at risk.
• Since last year, 91% of pharmacy owners have seen a “significant increase” in the problem.
• 99% of pharmacy workers found a drug was unavailable at least weekly, and 72% encountered that several times a day.

Pharmacists are finding themselves on the receiving end of abuse and hostility from patients who are frustrated and angered by not being able to get the drugs they have been prescribed.

Overall, 84% of pharmacy staff have experienced patient aggression, CPE said.

Experts said global supply and manufacturing problems were contributing to drug shortages. But Morrison added, “Low prices of medicines have made the UK a less attractive market for manufacturers, and this is contributing to the reduction in supply chain resilience.”

In?a major report?last month, the Nuffield Trust think tank warned that drug shortages had become a “new normal” and were being worsened by Brexit.

Mark Dayan , its?Brexit?programme lead, said: “Nearly every available indicator shows that since 2021, we have experienced a once-unthinkable level of medicines shortages again and again. The crisis jumps between products and conditions, with no sign of slowing down.”

While other Western countries, such as Italy and Germany, were also being hit by disruptions to supply, “Brexit creates some extra obstacles for the UK because our market is now partly separated from the wider European pool of supplies,” Dayan added.

Other drugs that remain in short supply include?insulin, which Type 1 diabetics need to take, and the liquid form of salbutamol, which is used to tackle?serious breathing problems?experienced by asthma patients.

Oral Rinse Study Opens Pathway for Early Detection of Gastric Cancer

A new study finds that analyzing bacteria in a simple oral rinse could allow early detection of gastric cancer or even signal warnings before the disease develops.

Researchers analysed bacteria samples from the mouths of 98 patients scheduled for endoscopy, including 30 known to have gastric cancer, 30 with pre-malignant gastric conditions and 38 healthy volunteers.

According to the study details released last Thursday and scheduled for presentation May 20 at the Digestive Disease Week meeting in Washington, D.C., they saw distinct differences between the bacteria assortment, or microbiome, in oral rinse samples from the healthy group and the cancerous and pre-cancerous patients.

There was very little difference between the bacteria from pre-malignant patients and those with cancer, suggesting that?alterations?in the microbiome may begin as soon as the stomach starts to undergo changes that can eventually turn into cancer.

Based on their findings, the authors developed a model of the 13 bacterial groups representing the most significant differences between controls and the cancer and pre-cancerous patients. They plan to conduct larger studies.

“No formal screening guidelines for gastric cancer are available in the United States, and more than half of patients with gastric cancer receive a diagnosis when the cancer is already at an advanced stage,” study leader?Dr Shruti Reddy Perati of Rutgers Robert Wood Johnson Medical School in New Brunswick, New Jersey said in a statement.

“The ideal time to try to prevent cancer is when it’s just about to turn into cancer,” Perati added. “As a screening and prevention tool, this has enormous potential.”