{"id":975,"date":"2026-07-29T21:41:00","date_gmt":"2026-07-29T12:41:00","guid":{"rendered":"https:\/\/onepress.co.kr\/index.php\/briefing\/2026-07-29-elephant-mrna-vaccine-en\/"},"modified":"2026-07-29T21:41:00","modified_gmt":"2026-07-29T12:41:00","slug":"2026-07-29-elephant-mrna-vaccine-en","status":"publish","type":"briefing","link":"https:\/\/onepress.co.kr\/index.php\/briefing\/2026-07-29-elephant-mrna-vaccine-en\/","title":{"rendered":"Elephants got an mRNA vaccine too, and two infected calves never became ill"},"content":{"rendered":"

2026-07-29 21:41 KST<\/strong><\/p>\n

Two juvenile Asian elephants given an experimental mRNA vaccine were naturally infected with a deadly virus but recovered without becoming ill.<\/p>\n

This is early evidence from only two calves, not proof of vaccine efficacy or a product ready for routine use.<\/p>\n

Why elephants needed a vaccine<\/h2>\n

Elephant endotheliotropic herpesvirus, or EEHV, can trigger rapidly progressing hemorrhagic disease in young Asian elephants.<\/p>\n

Calves are especially vulnerable as maternal antibodies decline. The papers describe a fatality rate near 65% among infected juveniles.<\/p>\n

Nine were vaccinated and two met the virus<\/h2>\n

The first study vaccinated nine Asian elephants at five US zoological institutions. The mRNA recipe taught their immune systems to recognize four proteins the virus uses to enter cells.<\/p>\n

Two calves, aged six and seven, received a first dose in October 2024 and a booster in November. They were naturally infected with EEHV1A in February and March 2025.<\/p>\n

\"Explanatory
ONEPRESS explanatory image: it visualizes elephant vaccine research and is not a photograph of the actual trial or participating elephants.<\/figcaption><\/figure>\n

Infected, but no treatment was needed<\/h2>\n

Blood tests confirmed the virus in both calves, yet viral loads remained low and neither developed clinical signs or blood abnormalities.<\/p>\n

The infections cleared without drugs or fluid therapy. Researchers say vaccine-induced immunity may have prevented progression to severe disease.<\/p>\n

Did mRNA work in an elephant-sized body?<\/h2>\n

All nine trial animals produced antibodies to vaccine targets, with increased responses lasting about six months in some elephants.<\/p>\n

No serious adverse effects were reported. Elephants younger than two responded less strongly, so age and dosing still need study.<\/p>\n

Why this is not yet proof<\/h2>\n

Only two vaccinated elephants encountered documented natural infection, and there was no unvaccinated control group. Naturally mild infections cannot be completely ruled out.<\/p>\n

The result is a first clinical protection signal. Larger, repeated studies are needed before a routine program for zoo and wild elephants can be defined.<\/p>\n

Official primary sources<\/h2>\n

Primary source: Journal of Virology: multi-antigen mRNA vaccine trial<\/a><\/p>\n

Primary source: Journal of Virology: first clinical protection case report<\/a><\/p>\n

Primary source: Houston Zoo research announcement<\/a><\/p>\n

Primary source: Baylor College of Medicine veterinary vaccine program<\/a><\/p>\n","protected":false},"excerpt":{"rendered":"

Nine Asian elephants received an experimental mRNA vaccine; two calves later infected naturally recovered without symptoms or treatment.<\/p>\n","protected":false},"featured_media":0,"template":"","meta":[],"class_list":["post-975","briefing","type-briefing","status-publish","hentry"],"_links":{"self":[{"href":"https:\/\/onepress.co.kr\/index.php\/wp-json\/wp\/v2\/briefing\/975","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/onepress.co.kr\/index.php\/wp-json\/wp\/v2\/briefing"}],"about":[{"href":"https:\/\/onepress.co.kr\/index.php\/wp-json\/wp\/v2\/types\/briefing"}],"wp:attachment":[{"href":"https:\/\/onepress.co.kr\/index.php\/wp-json\/wp\/v2\/media?parent=975"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}