MERS Vaccines 2023

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Last reviewed
September 18, 2023
Content Overview
MERS vaccine candidates protect people from severe infections generally related to interactions with camels and llamas in 2023.

Middle East Respiratory Syndrome (MERS) Vaccines 2023

The U.S. Food and Drug Administration (FDA) and the European Medicines Agency (EMA) have not approved a Middle East Respiratory Syndrome Coronavirus (MERS-CoV) vaccine candidate as of August 2023. Still, several vaccine candidates are conducting clinical trials. Efforts to develop an effective and safe human MERS-CoV vaccine have progressed, with a few vaccine candidates having reached human studies; these vaccines are based on DNA platforms (GLS-5300) and viral vector platforms (ChAdOx1) and modified vaccinia Ankara [MVA). On April 10, 2023, the U.S. government announced Project-NextGen, which intends to empower companies to expedite the development of vaccines and therapies for coronaviruses such as MERS. A study published by the  International Journal of Infectious Diseases on March 29, 2023, confirms MERS-CoV remains a threat to global health security. as variants continue circulating in humans and camels. In addition, recent recombination rates indicate co-infections with different MERS-CoV Clades: clade B (n=462), A (n=10), and C (n=5).

MERS-COV Vaccine Candidates 2023

Oxford University's Pandemic Sciences Institute and developer of the ChAdOx1 MERS vaccine announced on September 15, 2023, eighty-four people aged 50 to 70 will participate in a study in Liverpool, which follows two previous Phase I clinical trials in the U.K. and Saudi Arabia. 

MVA MERS-S (Modified Vaccinia virus Ankara) is a vaccine candidate that contains the full-length spike gene of MERS-CoV. Vaccination with MVA-MERS-S had a favorable safety profile without severe adverse events. Homologous prime-boost immunization induced humoral and cell-mediated responses against MERS-CoV. In June 2023, the U.S. CDC reported after a single modified vaccinia virus Ankara-MERS-S vaccination, seropositive camels showed increased levels of MERS-CoV‒specific T cells and antibodies, indicating the suitability of camel vaccinations in disease-endemic areas as a promising approach to control infection.

BVRS-GamVac-Combi is conducting phase 1/2 clinical studies sponsored by the Gamaleya Research Institute of Epidemiology and Microbiology, Health Ministry of the Russian Federation.

VTP-500 (ChAdOx1) MERS-CoV is a vaccine candidate from the University of Oxford that consists of the replication-deficient simian adenovirus vector ChAdOx1 MERS Spike protein antigen. The VTP-500 vaccine is administered as a single administration and with a homologous prime booster.

The inactivated rabies vectored SARS-CoV-2 S1 vaccine CORAVAX is adjuvanted with MPLA-AddaVax, a TRL4 agonist, induced high levels of neutralizing antibodies and generated a strong Th1-biased immune response. 

Avacc 101 vaccine candidate is designed to provide broad protection against SARS-CoV-1, SAR-CoV-2, and MERS-CoV. 

Novavax's MERS investigational vaccine was paused at the pre-clinical process.

MERS Cases 2023

The U.S. Centers for Disease Control and Prevention (CDC) says MERS is a viral respiratory infection. The zoonotic source of this virus remains unknown; however, since the first report of MERS-CoV infection in a patient with pneumonia who died in a Jeddah hospital in Saudi Arabia in 2012, about 2,605 cases with 945 associated fatalities (36%) have been reported from 27 countries in six World Health Organization.


A study published by the journal Nature in March 2023 stated it is generally believed that sarbecoviruses, such as SARS-CoV-2 and SARS-CoV, use angiotensin-converting enzyme 2 (ACE2) as the entry receptor, while merbecoviruses, such as MERS-CoV, HKU4, and HKU25, utilize dipeptidyl peptidase 4 (DPP4) as the entry receptor. Previous findings (2022) reveal a potential zoonotic threat that MERS-CoV could, during its evolution, be gaining the ability to use hACE2 as an entry receptor and, thus, could also coinfect ACE2-expressing cells with SARS-CoV-2.

MERS-CoV News 2023

September 15, 2023 - Oxford and Liverpool scientists launch a new MERS vaccine phase 1 clinical trial.

May 2023 - The Lancet published Vaccination strategies for mitigating MERS-CoV outbreaks. Affected countries should have plans for maintaining MERS-CoV vaccine stockpiles that are sufficiently available and ready to use, especially in populations at high risk of infection during outbreaks.

March 3, 2023 - Abstract: MERS-CoV clade B viruses are found in camelids and humans in the Middle East, but clade C viruses are not. The kinetics by which llamas shed infectious MERS-CoV are similar to those of dromedary camels. We provide experimental evidence for the extended shedding of MERS-CoV clade B viruses in llamas, which might explain why they outcompete clade C strains in the Arabian Peninsula.

December 7, 2022 - The journal Nature published an article: Close relatives of MERS-CoV in bats use ACE2 as their functional receptors, that describes MERS-CoV-related viruses that use ACE2 as an entry receptor, underscoring a promiscuity of receptor use and a potential zoonotic threat.

January 31, 2022 - The peer-reviewed Frontiers in Immunology published an ORIGINAL RESEARCH article: Inactivated Rabies Virus Vectored MERS-Coronavirus Vaccine Induces Protective Immunity in Mice, Camels, and Alpacas. The current results demonstrate that the inactivated rabies virus-vectored MERS-CoV vaccine is safe, efficacious, and can induce robust protective immune responses, representing a promising MERS camelid vaccine candidate and warranting further efficacy study.

January 28, 2022 - The Journal of Microbiology published: the MERS coronavirus vaccine development: Updating Clinical Studies using platform technologies.

November 4, 2021 - Vaccitech plc announced the publication in The Lancet Microbe of the first Phase 1 clinical trial conducted in the Middle East evaluating the safety and tolerability of the ChAdOx1 MERS (Middle Eastern Respiratory Syndrome) vaccine candidate.

November 3, 2021 - The Lancet published: Safety and immunogenicity of ChAdOx1 MERS vaccine candidate in healthy Middle Eastern adults (MERS002): an open-label, non-randomized, dose-escalation, phase 1b trial. Results Interpretation: The acceptable safety and immunogenicity data from this phase 1b trial of the ChAdOx1 MERS vaccine candidate in Healthy Middle Eastern adults, combined with previous safety and immunogenicity data from a trial in the U.K., support selecting the ChAdOx1 MERS vaccine for advancement into phase 2 clinical evaluation.

August 4, 2021 - INOVIO announced that the company had dosed the first subject in its Phase 2 trial to evaluate INO-4700, its DNA vaccine candidate for preventing MERS.

April 14, 2021 - A team of researchers in the Kingdom of Saudi Arabia studied the antibody responses in 48 human MERS-CoV infection survivors with variable disease severity in Saudi Arabia. MERS-CoV–specific neutralizing antibodies were detected for six years after postinfection. Choe et al. showed that patients with severe disease had robust MERS-CoV neutralizing antibody titers for one year. Conversely, patients with mild disease had waning antibody responses over time. 

July 24, 2019 - The Lancet published: Safety and immunogenicity of an anti-Middle East respiratory syndrome coronavirus DNA vaccine: a phase 1, open-label, single-arm, dose-escalation trial. Interpretation - The GLS-5300 MERS coronavirus vaccine was well tolerated with no vaccine-associated serious adverse events. Immune responses were dose-independent, detected in more than 85% of participants after two vaccinations, and durable through 1 year of follow-up. The data support further development of the GLS-5300 vaccine, including additional studies to test the efficacy of GLS-5300 in a region endemic to MERS coronavirus.