Vaccine Info

mRNA-1893 Zika Vaccine

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Last reviewed
July 11, 2021

mRNA-1893 Zika Vaccine Description

Moderna's mRNA-1893 contains an mRNA sequence encoding for the structural proteins of the Zika virus and is designed to cause cells to secrete virus-like particles, mimicking the response of the cell after natural infection.

mRNA-1893 Zika Vaccine Indication

mRNA-1893 is indicated for avoiding transmission of the Zika disease from a mother to an unborn child

mRNA-1893 Zika Vaccine Dosage

Interim Phase 1 Data - All four cohorts (10 µg, 30 µg, 100 µg, 250 µg) of the Phase 1 study of mRNA-1893 have been dosed. An interim analysis of the study reports safety and immunogenicity data from the 10 µg and 30 µg cohorts. Neutralizing antibody titers were assessed using Plaque Reduction Neutralization Test (PRNT50) and microneutralization assays (MN), which provide equivalent guidance for interpreting the neutralizing immune response.

Following a two-dose vaccination schedule of mRNA-1893 given 28 days apart, the 10 µg and 30 µg dose levels were both generally well-tolerated, and there were no vaccine-related serious adverse events (SAEs) or adverse events of special interest (AESI). The most frequent solicited adverse reaction was local pain at the injection site. The safety profile did not appear affected by the second vaccination nor a flavivirus-positive baseline serostatus.

The analysis also showed that the 10 µg and 30 µg dose levels induced a neutralizing antibody response in both flavivirus infection-naïve (seronegative) participants and in participants with pre-existing flavivirus antibodies (seropositive), as shown by geometric mean titers and seroconversion rates. Notably, a single vaccination of the 30 µg dose level was sufficient to convert baseline flavivirus seronegative participants.

However, there was a clear benefit of a two-dose series given 28 days apart.

mRNA-1893 Zika Vaccine News

April 14, 2020 - First interim analysis of Phase 1 Zika vaccine candidate (mRNA-1893) study shows that 10 µg and 30 µg dose levels seroconverted 94% and 100% of seronegative participants, respectively, and effectively boosted seropositive participants; both dose levels generally well-tolerated.

August 19, 2019 - Moderna Inc. announced that the Food and Drug Administration had approved its potential vaccine for the Zika virus for a fast track to approval. Fast Track is designed to facilitate the development and expedite the review of therapies and vaccines for serious conditions and fill an unmet medical need. Programs with Fast Track designation may benefit from early and frequent communication with the FDA, in addition to a rolling submission of the marketing application. 

mRNA Technology

Recognizing the broad potential of mRNA science, Moderna set out to create an mRNA technology platform that functions very much like an operating system on a computer. It is designed so that it can plug and play interchangeably with different programs. The "program” or “app” is the mRNA drug - the unique mRNA sequence that codes for a protein.

Generally, the only thing that changes from one potential mRNA medicine to another is the coding region – the actual genetic code that instructs ribosomes to make protein.

Utilizing these instruction sets gives the investigational mRNA medicines a software-like quality. Moderna also has the ability to combine different mRNA sequences encoding for different proteins in a single mRNA investigational medicine.

mRNA-1893 Zika Vaccine Clinical Trials

mRNA-1893 Zika vaccine is currently being studied in two clinical trials.