Israel's military assault may trigger a polio epidemic in Gaza if vaccines can't reach people

During the recent Democratic National Convention in Chicago, half a dozen doctors assembled to protest the public health crisis caused by Israel's ongoing military onslaught in Gaza. While the physicians spoke in large part of bombs, gunfire and the other direct consequences of armed conflict, the region faces another serious threat: poliovirus, which has been detected in Gaza wastewater since July.

"Polio could cause a serious epidemic in Israel, the region and beyond. Polio and other infectious diseases know no boundaries." — Partially conceding to the humanitarians' outrage, Israelannounced on Thursday that it will implement a series of pauses in fighting throughout September to distribute vaccines. Perhaps Israel had no choice; the reality of a variant type 2 poliovirus outbreak in Gaza had the whole region bracing for a public health crisis. Israel has already killed at least 40,000 people, including 16,000 children. Israel's military campaign began following the Hamas-led October 7th attack killed around 1,200 Israeli people, including many civilians and children. But a major epidemic would only make things worse and could potentially spread polio to other countries.

Hence why on Monday more than 1.2 million doses of the novel oral polio vaccine type 2 were delivered to Gaza, courtesy of a coalition of humanitarian groups including the World Health Organization (WHO), UNRWA (the main United Nations agency for aiding Palestinians) and UNICEF, the UN children's fund. According to experts who spoke with Salon, all of this is a big step in the right direction.

At the same time, the potential calamity has not yet been averted because Israel's ongoing assault and the current damage to Palestinian infrastructure will still make it difficult to get shots in the arms that need them at the time they are needed.

"This is the correct vaccine for the current outbreak," Dr. William Haseltine, a pioneer in fighting HIV/AIDS and chair and president of the global health think tank Access Health International, told Salon. After praising the vaccine itself and saying that overall it is a "very good move" that the shots are now in Gaza, he added that if the problem is not effectively addressed "polio could cause a serious epidemic in Israel, the region and beyond. Polio and other infectious diseases know no boundaries. This is yet another consequence of destroying all the infrastructure in a neighboring country."

Dr. Georges C. Benjamin, executive director of the American Public Health Association (APHA), also warned that polio is such a highly infectious disease, even a moderate outbreak in Gaza could easily spread through the region. As such, APHA is calling for a ceasefire "in order to distribute humanitarian aid and to address health risks like this one," Benjamin told Salon. "We also have called for the release of the hostages and for a rapid negotiated settlement of the hostilities."

Even if a ceasefire occurs, however, Israel has already caused so much damage to the region's infrastructure that it will be very challenging at this point to prevent an outbreak.

"First getting the first shot to every eligible individual is challenging but tracking these individuals for their second shot will be very, very challenging because the people don’t have a fixed location," Benjamin said. "Also the disease spreads easily in crowded conditions and where hygiene and routine environmental cleaning is not available."

Want more health and science stories in your inbox? Subscribe to Salon's weekly newsletter Lab Notes.

The reemergence of polio is particularly notable because the disease has been defeated in the past, and in theory should be easy to contain again. When Dr. Jonas Salk announced that he had developed a polio vaccine in April 1955, he not only helped eradicate an epidemic but revolutionized the science of developing vaccines in the process. In a sense, the history of fighting polio and the history of developing innovative vaccines are one and the same story. Yet polio could always become a global menace again if it happens to pop up in an area where people do not have ready access to effective inoculations.

"This is a tragic situation in that polio is one of the infections worldwide that we are hoping to eradicate and this reappearance of polio in the region absolutely can lead to spread outside of the Middle East," Dr. Monica Gandhi, an infectious disease doctor and professor of medicine at the University of California–San Francisco, told Salon. "The effects of war and the destruction of infrastructure in the region has led to exposure to raw sewage and a lack of clean water in the region, which is exposing tens and thousand of Palestinians to polio which is already circulating in the wastewater and has led to the partial paralysis of a 10-month old child."

Vaccines would prevent many more children from suffering a similar fate. The nOPV2 vaccine is very effective. Dr. Russell Medford, CEO of Covanos and Chair of the Global Center for Medical Innovation at the Georgia Institute of Technology, cited a 2024 study in The Lancet which found the vaccine was both immunoprotective and safe in a trial including 2345 infants and 600 young children in the Gambia.

"The nOPV2 vaccine is expected to effectively interrupt poliovirus transmission and thus markedly reduce the risk of seeding further polio outbreaks," Medford said. His views were echoed by Dr. Alfred Sommer, dean emeritus and professor of epidemiology at Johns Hopkins Bloomberg School of Public Health.

"Since these vaccines were supplied through UNICEF/WHO, I would expect they are standard, highly effective vaccines that have been used to eradicate polio around much of the world, particularly in low-resource populations," Sommer said. "We were on the cusp of eradicating this dreaded disease a few years ago, but the virus remained active in areas where vaccination efforts were less than ideal, and keep spreading from there to re-infect once polio-free zones."

Benjamin also emphasized that the context of war is crucial to understanding the current polio outbreak.

"The public health implications of conflict are enormous and include the physical and mental health trauma for the populations impacted," Benjamin said. "Violence is never a way to solve our differences and should be avoided."