Ending The Pachyderm Plague

Behind Colossal’s Efforts to Save Baby Elephants from a Deadly Virus

BY Stefano Daza Arango

It was a spring day in 2009, and the staff at the Columbus Zoo and Aquarium buzzed with excitement. After a long 655-day pregnancy, Phoebe, one of the zoo’s female Asian elephants, had finally gone into labor. Now, after almost two years of diligently caring for all the needs of the expecting giant, her caretakers could do nothing but wait for the arrival of her calf. As the hours dragged on, their tension and anticipation grew. And then, it happened. Beco, the zoo’s newest Asian elephant, was born (1).

Baby Beco became an instant sensation, capturing the hearts of everyone who laid eyes on him. Visitors from across the country flocked to Columbus to see him, mesmerized by the delightful sight of this tiny elephant, who exhibited an unmistakable zest for life. He weighed a whopping 303 lbs at birth, and his name—a combination of his parents’ names, Phoebe and Coco—was chosen through a public vote (2).

A juvenile Beco romping on his favorite balls just months after his birth. He was known and loved for his high energy and playful nature. Source: Grahm Jones /  Columbus Zoo and Aquarium

For years, Beco continued to charm visitors and caretakers with his tender moments, playful demeanor, and endearing antics. As he grew into adulthood, his energetic personality remained, and he played an increasingly important role in his herd (2). In May of 2022, Beco celebrated his 13th birthday, and things at the Columbus Zoo’s elephant herd were going well. Or so it appeared.

On what was to be a fateful Thursday morning in June 2022, Beco’s behavior seemed… odd. The once-energetic elephant suddenly became lethargic and showed very little interest in his usual activities. His caretakers, sensing something was amiss, quickly collected blood samples and sent them to the Smithsonian’s National Zoo for analysis. That evening, the results confirmed their worst fears: Beco had tested positive for the Elephant Endotheliotropic Herpesvirus (EEHV) – a deadly virus ravaging elephants worldwide (2). 

Upon receiving the diagnosis, the Columbus team wasted no time in attempting to save their beloved elephant. They administered antiviral medication and fluids, in addition to regular plasma infusions, whole blood, and stem cells (2). But despite their best efforts and round-the-clock work, the disease spread rapidly. That Saturday morning, just two days after the first signs of illness appeared, the young elephant passed away.

EEHVs: The Stealthy Killers

The news of Beco’s passing sent shockwaves through the zoo community, leaving a void in the hearts of the zookeepers and visitors who loved, admired, and cherished him. His story is not an isolated case but a tragic example of a prevalent disease ravaging elephants around the world.

EEHVs are a unique set of herpesvirus that infect only elephants (3). In some young elephants, primary infection with EEHV results in spread through the bloodstream, viciously attacking endothelial cells (the cells lining blood vessels) and triggering a deadly and horrific hemorrhagic disease (EEHV-HD) (4). The disease causes rapid internal bleeding, organ failure, and often death. As seen in Beco’s tragic demise, EEHV-HD is also a swift killer that can claim the life of a healthy elephant within a matter of days (3)(5)(6).

The most heart-wrenching aspect of EEHVs are their primary target: young elephants. Those between 1-15 years of age are most threatened, with the viruses accounting for nearly half of young elephant deaths in North American zoos. Asian elephants are the species most affected by EEHVs, suffering a fatality rate between 65% to 80% (3)(6). African elephants are also susceptible, but their fatality rate is generally lower (4).

Currently, multiple genetically distinct strains of EEHV have been identified (3), with EEHV1 being the most common and deadly to young Asian elephants. EEHV1 is further divided into two subtypes, EEHV1A and EEHV1B, which collectively are responsible for the majority of juvenile Asian elephant fatalities in captivity and in the wild (7).

Much like human herpes, it is believed that elephants have coevolved with EEHVs for millions of years. In fact, most adult elephants are thought to be carriers of the virus, having survived exposure and infection at some point in their lives (4). Scientists have yet to pinpoint the exact triggers that cause the virus to reactivate, but factors like stress, immune system suppression, or other environmental influences may play a role (5). Evidence is accumulating that suggests maternally acquired antibodies against EEHV might be protective, but should elephants get infected after these antibodies have declined or are undetectable, they appear to be especially vulnerable to clinical disease after infection with EEHV. (7).

Elephant Recovery at Risk

Beyond the conservation community, EEHV-HD remains largely unknown, and this “pachyderm plague” might not come to mind when considering the numerous threats facing elephants today. However, with fewer than 52,000 Asian elephants remaining and EEHVs being the leading cause of death in captive elephant calves as well as a major threat in the wild, there is significant cause for concern (8). 

In recent years, several heart-wrenching stories of juvenile elephants succumbing to EEHVs have shaken the zoo community. In 2019, the Indianapolis Zoo lost Kalina and Nyah, two young African elephants who died suddenly within days of each other (9). In 2020, Batu and Ajay, two young Asian elephants at the Rosamond Gifford Zoo in Syracuse, New York, fell victim to the lethal virus within months of each other (10). In 2021, Toledo Zoo mourned the loss of Lucas, a 9-year-old African elephant (11), and later that year, Thorn, a 3-year-old Asian elephant calf at ABQ BioPark Zoo in New Mexico, tragically passed away on Christmas Day (12). Most recently, Ajabu, the much-beloved 7-year-old African elephant at the Dallas Zoo, passed away after losing a battle with EEHV (20).

Ajabu celebrates his first birthday in 2017. He survived a case of EEHV in 2021, but tragically passed away this May after a two-week battle with a second bout of the virus. Source: Vernon Bryant / The Dallas Morning News 


The cases mentioned above represent only a fraction of EEHV-HD fatalities in U.S. zoos, with similar fatality rates occurring internationally. Although well-documented in captive elephants, the impacts of EEHVs on wild elephants can be challenging to quantify accurately. Most countries with free-ranging populations lack the testing tools necessary to diagnose EEHVs, although capacity is slowly improving (4).

As global elephant populations grapple with extreme pressures from poaching, habitat fragmentation, and human-elephant conflict, EEHVs threaten to worsen their already precarious conservation status (13).

“Elephant reproductive sustainability is severely threatened by the elephant endotheliotropic herpesviruses.” 

— Virginia Riddle Pearson, Colossal Conservation Advisory Board Member, Leading EEHV Expert

Outbreaks in wild populations can lead to a rapid decline in the number of juveniles. Given that elephants are slow breeders (females give birth to a single calf approximately every 4-5 years), the loss of young elephants carries profound implications for the reproductive success of a herd and the long-term survival of the species (14).

A Colossal Plan to Stop EEHV

At Colossal, we recognize the severity of the EEHV crisis and are dedicated to developing effective treatments and vaccines to protect elephants from this deadly herpesvirus.

To achieve this ambitious goal, we have partnered with the world’s leading EEHV researcher, Dr. Paul Ling, a professor in the Department of Microbiology and Virology at Baylor College of Medicine in Houston, Texas, and a member of Colossal’s Scientific Advisory Board (15).

Paul Ling, Ph.D. Colossal Scientific Advisory Board Member, Professor in the Department of Microbiology and Virology at Baylor College of Medicine; Colossal EEHV Lead. Source: Houston Chronicle

In an interview with Newsweek, our CEO Ben Lamm expressed enthusiasm about the partnership, stating: “Colossal is very excited to be collaborating with Paul Ling of the Baylor College of Medicine. Dr. Ling is the world’s foremost expert on EEHV and has single-handedly saved more elephants than we’ll ever know through his innovations in creating viral detection assays that allow us to treat elephants before they ever show symptoms of illness (8)”

Dr. Ling’s lab has made significant progress in identifying specific proteins from the EEHV virus. Together, we are working to engineer these proteins into a vaccine that trains elephants’ immune systems to mount a defense against the deadly pathogen. Furthermore, we are developing a “second-generation” vaccine using cutting-edge mRNA technologies, similar to the Pfizer and Moderna COVID shots.

Matt James, our Chief Animal Officer, explains that these vaccines will introduce a segment of messenger RNA into elephants’ cells, prompting them to generate proteins unique to the EEHV virus. This, in turn, stimulates the elephants’ immune systems to create protective antigens against the virus (8).

While vaccines are powerful tools in our fight against EEHVs, they alone are not sufficient. To provide life-saving care to critically ill elephants already infected with EEHV, we are also developing potent monoclonal antibody treatments.

Our vaccine and treatment work builds upon our efforts to sequence and open-source the entire genomes of African, Asian, and Forest elephant populations (3). By producing population sequence data on hundreds of African and Asian elephants, we can better understand elephant population genomes and possibly identify any genetic susceptibility to EEHVs.

“I am so thankful that two of Colossal Biosciences’ main goals are to propagate the EEHVs in vitro to aid development of vaccines and therapeutics against EEHVs-HD and to sequence (in cooperation with the International Vertebrate Genome Project) entire genomes of dwindling African and Asian elephant populations to potentially identify any genetic susceptibility to EEHVs-HD and to aid in management decisions to foster genetically sustainable wild and captive”

— Virginia Riddle Pearson, Colossal Conservation Advisory Board Member, Leading EEHV Expert


Virginia Riddle Pearson is a Colossal Conservation Board Member who has been helping conserve elephants for more than half a century. She has identified a number of new strains and substrains of EEHVs and EGHVs (the Elephant Gammaherpesviruses) in African and Asian elephants, both captive and wild. Source: Virginia Riddle Pearson

We hope that our EEHV work not only accelerates the development of life-saving technologies for elephants but also inspires other research groups globally to join the battle against EEHVs. With multiple research teams working collaboratively, we believe we can make a real difference in the fight to save the world’s elephants.

A Better Future for Elephants (and Mammoths)

As our team continues to push the boundaries of biotechnology in our ambitious endeavors to bring the mammoth back from extinction, we remain equally committed to using those same groundbreaking innovations to preserve and restore resilient populations of living elephants today.

“Colossal’s commitment to eradicating EEHV’s deadly effect on elephants will also serve to protect our future populations of woolly mammoths. This research enhances our understanding of elephant, and therefore mammoth, immune responses and will allow Colossal to arm both elephants and mammoths with traits to protect them against this deadly disease (16).”

 — Ben Lamm, Co-founder and CEO of Colossal


By developing treatments and vaccines for EEHVs, Colossal can help keep young elephants healthy and alive. Source: Discovery 

Our collaboration with Dr. Paul Ling signifies a pivotal step in the journey towards vanquishing EEHVs, and it represents just one of the many exciting projects we have launched for the conservation of elephants. By continuing to pursue innovative vaccines, revolutionary treatments, and comprehensive genome research, we strive to create a future where all elephants can thrive, free from the shadow of this deadly virus.

“Disruptive conservation methods rooted in genetics complement existing preservation efforts, and ensure a future for all elephants to thrive (16).” 

— Matt James, Chief Animal Officer at Colossal 

As we honor the memory of Beco and all the elephants who have succumbed to EEHV-HD, their stories serve not only as powerful reminders of the urgency of our work but also as beacons of hope. Together, we are forging a path towards a world where young elephants (and, eventually, young mammoths) can grow and flourish, contributing to the vibrancy of their herds and enriching the tapestry of life on our planet –  just as Beco once did for those who cherished him.



  1. Writer, Staff. “Zoo’s Baby Elephant Has a Name: BECO.” The Columbus Dispatch, The Columbus Dispatch, 11 May 2009, https://www.dispatch.com/story/news/2009/05/11/zoo-s-baby-elephant-has/23522623007/.
  2. FIELDS, JEN. “Columbus Zoo and Aquarium Heartbroken after Sudden Loss of 13-Year-Old Elephant, Beco.” Columbus Zoo and Aquarium Heartbroken After Sudden Loss of 13-Year-Old Elephant, Beco | Columbus Zoo and Aquarium, https://www.columbuszoo.org/news/columbus-zoo-and-aquarium-heartbroken-after-sudden-loss-13-year-old-elephant-beco.
  3. “Elephant Conservation.” Colossal Biosciences, https://colossal.com/elephant-conservation/.
  4. “EEHV and the North American Advisory Group.” Association of Zoos & Aquariums, https://www.aza.org/connect-stories/stories/elephant-endotheliotropic-herpesvirus-eehv-research-detection-treatment-advisory-group.
  5. Mikota, Susan. “Elephant Disease Fact Sheets .” Elephant Care International, https://web.archive.org/web/20060223062153/http://www.elephantcare.org/herpes.htm.
  6. “EEHV .” New Mexico BioPark Society , https://www.bioparksociety.org/main/eehv/.
  7. Fuery, Angela, et al. “Lethal Hemorrhagic Disease and Clinical Illness Associated with Elephant Endotheliotropic Herpesvirus 1 Are Caused by Primary Infection: Implications for the Detection of Diagnostic Proteins.” Journal of Virology, U.S. National Library of Medicine, 17 Jan. 2020, https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7000966/.
  8. Georgiou, Aristos. “Mammoth De-Extinction Firm Turns Sights on Saving Elephants from Same Fate.” Newsweek, Newsweek, 7 Oct. 2022, https://www.newsweek.com/mammoth-de-extinction-firm-turns-sights-saving-elephants-same-fate-1749986.
  9. Clark, Andrew, and Crystal Hill. “Indianapolis Zoo Elephants: What We Know about the Deaths of Kalina and Nyah.” The Indianapolis Star, Indianapolis Star, 31 May 2019, https://www.indystar.com/story/news/2019/03/27/indy-zoo-elephant-dies-kalina-nyah-eehv/3288996002/.
  10. Bender, Kelli. “’Heartbroken’ New York Zoo Loses Two Young Elephants to ‘Lethal’ Virus in One Week.” Peoplemag, PEOPLE, 15 Dec. 2020, https://people.com/pets/new-york-rosamond-gifford-zoo-two-elephant-deaths/.
  11. Todisco, Eric. “’Beloved’ 9-Year-Old Elephant Named Lucas Dies of ‘Devastating’ Viral Disease at Toledo Zoo.” Peoplemag, PEOPLE, 15 Apr. 2021, https://people.com/pets/young-elephant-dies-viral-disease-toledo-zoo/.
  12. “Asian Elephant Calf Dies of Elephant Endotheliotropic Herpesvirus.” City of Albuquerque, https://www.cabq.gov/artsculture/biopark/news/asian-elephant-calf-dies-of-elephant-endotheliotropic-herpesvirus.
  13. “National Elephant Herpesvirus Laboratory.” Smithsonian’s National Zoo, 19 July 2016, https://nationalzoo.si.edu/animals/national-elephant-herpesvirus-laboratory.
  14. 14, “Elephant.” WWF, World Wildlife Fund, https://www.worldwildlife.org/species/elephant.
  1. “Our Advisors.” Colossal Biosciences, 26 Apr. 2023, https://colossal.com/advisors/.
  2. “Saving Baby Elephants from a Deadly Herpes Virus.” Discovery, 5 Oct. 2022, https://www.discovery.com/science/elephant-vaccine. 
  3. “Start Your Adventure: Creating Unforgettable Experiences.” Chester Zoo, 17 Apr. 2023, https://www.chesterzoo.org/. 
  4. Homepage – Toledo Zoo & Aquarium, https://www.toledozoo.org/. 
  5. Feldman, Claudia. “Baylor Doctor Dedicated to Saving Young Elephants.” Houston Chronicle, 11 Oct. 2015, https://www.houstonchronicle.com/life/article/Baylor-doctor-dedicated-to-saving-young-elephants-6564175.php.
  6. 20. Jones, Aria. “Dallas Zoo Mourns Death of African Elephant Ajabu After Viral Infection.” Dallas News, 10 May 2023, www.dallasnews.com/news/2023/05/10/dallas-zoo-mourns-death-of-african-elephant-ajabu-after-viral-infection/.