Breakthrough vaccine trial for common baby virus

31 July 2020

31 July 2020

A ground-breaking vaccine could reduce the number of babies hospitalised for Respiratory Syncytial Virus by nearly 50 per cent, according to new research.

Women's and Children's Hospital (WCH) Senior Medical Practitioner and Professor in Vaccinology at the University of Adelaide, Professor Helen Marshall, said the large international study assessed the safety and effectiveness of a vaccine used in pregnancy to protect newborn babies against a common and potentially severe respiratory infection.

“The Respiratory Syncytial Virus (RSV) is the most common cause for babies under the age of one to be admitted to hospital in Australia,” Prof Marshall said.

“It causes infection of the lungs and respiratory tract and is so common that most children experience the virus by the age of two, with the most severe cases found in the youngest infants.

“The virus can cause pneumonia and respiratory failure and sometimes death. It can also lead to long-term effects such as persistent wheezing.”

The WCH was one of 87 centres around the world to take part in the study which saw healthy pregnant women aged between 18 and 40 years given a single dose of the vaccine as they neared the end of their pregnancy.

They were then monitored over the course of their pregnancy and their babies assessed weekly during the first six months of their life for any signs of the virus.

Almost all women (98%) who received the RSV vaccine responded well to the vaccination by producing antibodies against the RSV disease.

The vaccine was found to reduce hospitalisation due to RSV by around 45 per cent and reduce hospitalisation for infants with severe RSV disease by almost 50 per cent.

Infants of vaccinated mothers were also 46 per cent less likely to have a severe respiratory disease of any cause.

Professor Marshall said it is the first vaccine in over 20 years of RSV vaccine development to show protection against the virus.

“Infants are at highest risk of severe outcomes from RSV in the first few months of their life, which is why it so exciting for us to see evidence of the effective transfer of protective antibodies from mother to baby,” Prof Marshall said.

“The results of this study are incredibly encouraging however further research will be required to definitely establish the vaccine’s effectiveness in preventing all RSV disease in infants including milder cases.”

The Vaccination of Pregnant Women with Respiratory Syncytial Virus Vaccine and Protection of their Infants has been published in the New England Journal of Medicine.