About the Rhyme Trial

The purpose of the Rhyme Trial is to evaluate the safety of, and immune system’s response to, 2 investigational vaccines. These investigational vaccines, called mRNA-1345 and mRNA-1365, are being evaluated to see if they can protect against respiratory syncytial virus (RSV) and human metapneumovirus (hMPV) in children ages 5–23 months. RSV and hMPV cause infections of the lungs and respiratory tract. Globally, these viruses are responsible for millions of respiratory tract infections and hospitalisations, and young children are particularly susceptible to serious infection. Despite this high disease burden, there is currently limited information on treatments for RSV and hMPV.

About the Investigational Vaccines

The investigational vaccines being evaluated in this clinical trial are called mRNA-1345 and mRNA-1365. Unlike standard vaccines, they are not made from a weakened or killed virus. Instead, they include a man-made version of a molecule called messenger ribonucleic acid (mRNA), which provides the body with instructions on how to potentially defend against a virus. mRNA makes a harmless protein that replicates the virus, triggering the body’s immune system to create antibodies. Through this natural process, the immune system may create the antibodies it needs if it ever encounters the real RSV or hMPV viruses. It is hoped that these antibodies will then be able to fight the viruses.

The investigational vaccines break down naturally and do not stay in the body. These investigational vaccines have not been tested in adults, but similar investigational vaccines against RSV and hMPV have been given to adults and children. Several other clinical trials evaluating similar investigational mRNA vaccines are also in progress.

What to Expect

Participation in the Rhyme Trial will last 24 months and includes up to 9 visits to a trial site and up to 18 phone calls.

Your child will be given 3 injections in the upper arm or leg. They will be chosen at random to receive either mRNA-1345, mRNA-1365, a placebo, or active control (in the UK, dose 3 in the placebo group will be replaced by the Nimenrix vaccine).

Your child will have up to 4 blood sample tests during the trial.

You will have up to 18 phone calls with the trial doctor after your child’s injections to monitor for any side effects.

You will be asked to use an eDiary app on your smartphone or a provided smartphone to report any side effects your child might experience for 6 days after each injection.

Your child will be closely monitored by the trial team if any symptoms of RSV or hMPV are reported at any time throughout their participation.

If you would like to find out more, please read the participant information sheet

If you are interested in joining the study or would like any further information regarding the study, please contact us on:

Email info@ovg.ox.ac.uk, Tel: 01865 611400

Kind Regards,

The Oxford Vaccine Group