RSV vaccine for pregnant women provides protection for babies

Publicly released:
Australia; International; WA
Respiratory_syncytial_virus_(RSV)_infection_x400 By - Yale Rosen collection, CC BY-SA 2.0
Respiratory_syncytial_virus_(RSV)_infection_x400 By - Yale Rosen collection, CC BY-SA 2.0

In a 'gold standard' medical trial including 7,358 pregnant women, international researchers, including Australians, found administering the bivalent RSV prefusion F protein–based (RSVpreF) vaccine was 81.8% effective in preventing severe RSV in infants within 90 days of birth, and 69.4% effective in preventing severe disease within 180 days of birth. The vaccine was given to 3,682 women, while 3,676 received a non-active placebo. Adverse events reported within a month of receiving the injection were similar in the vaccine and placebo groups at around 13%, the researchers say. A related study, published at the same time, found the vaccine is also effective and safe for use in adults aged 60 and over. Both trials were funded by Pfizer, which manufactures the vaccine.

Media release

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A world-first study has found a new vaccine against potentially deadly respiratory syncytial virus (RSV) is safe and effective for use in pregnant women, to help protect their babies.

The phase-3 clinical trial in 18 countries, including Australia, found the Pfizer RSVpreF vaccine helped protect newborns from lower respiratory tract infections caused by RSV – one of the leading causes of hospitalisation for babies globally.

RSV is responsible for more than 100,000 deaths and 3.6 million hospitalisations in children around the world each year.

It infects the airways and lungs and can lead to life-threatening complications such as bronchiolitis and pneumonia.

A paper published in the prestigious New England Journal of Medicine found the vaccine, given to women who were between 24 and 36 weeks pregnant, gave their babies protection from severe RSV for up to 180 days after birth.

Professor Peter Richmond, Head of the Vaccine Trials Group at the Wesfarmers Centre of Vaccines and Infectious Diseases, based at the Telethon Kids Institute, Head of Paediatrics at The University of Western Australia and Head of Immunology at Perth Children’s Hospital, said the trial also found the vaccine to be safe for mums and their unborn babies.

“There was a significant spike in the number of RSV cases in Australia last winter as we were coming through COVID, and we know that the highest risk age group for RSV is babies in the first two to three months of life,” Professor Richmond said.

“The findings of this study are really significant in the fight against RSV in Australia."

Telethon Kids Institute was the lead site in Australia for the study.

Currently, there is no vaccine against RSV suitable for babies, but Professor Richmond said a long-lasting monoclonal antibody treatment for babies was likely to be on the market within 12 months.

“As a paediatrician who has looked after sick babies with RSV for more than 30 years, the idea that we could prevent a large proportion of these illnesses is fantastic and I feel privileged to have been involved in the process,” he said.

“I believe the potential burden of disease we may be able to prevent will be even greater than first thought, including decreasing the amount of antibiotics that are prescribed, reducing ear infections in young babies and decreasing more serious bacterial pneumonias that are associated with RSV infection.

“There is also the potential benefits of preventing longer-term complications such as chronic lung infections and asthma.”

Professor Richmond said a suite of potential vaccines for RSV was exciting news for parents in Australia and overseas.

“In the next 10 years I hope to see licensed vaccines and preventative drugs being given to mothers, babies, toddlers and older adults, with multiple vaccine and monoclonal antibody platforms available that could even be combined with COVID and influenza vaccines, helping keep our hospitals and GP surgeries much quieter over winter.

“The biggest challenge will be ensuring these vaccines are accessible and affordable in low and middle-income countries where more than 99 per cent of RSV deaths occur, especially given the effectiveness shown in the large Phase 3 trials included countries across Africa, Latin America and Asia.”

Professor Richmond urged parents of newborns to be aware of the symptoms of RSV heading into winter.

“I am concerned that parents may not be aware of RSV and the pivotal role it plays in serious infections in young children,” he said.

“If you have any concerns about your baby if they have difficulties with breathing or feeding, please don’t hesitate to seek medical advice.”

For more information about RSV research by the Wesfarmers Centre of Vaccines and Infectious Diseases or to register your interest for upcoming studies, please visit infectiousdiseases.telethonkids.org.au or email vtg@telethonkids.org.au

Attachments

Note: Not all attachments are visible to the general public. Research URLs will go live after the embargo ends.

Research Massachusetts Medical Society, Web page Bivalent Prefusion F Vaccine in Pregnancy to Prevent RSV Illness in Infants. The URL will go live after the embargo ends
Research Massachusetts Medical Society, Web page Efficacy and Safety of a Bivalent RSV Prefusion F Vaccine in Older Adults. The URL will go live after the embargo ends
Editorial / Opinion Massachusetts Medical Society, Web page RSV Illness in the Young and the Old — The Beginning of the End? The URL will go live after the embargo ends
Journal/
conference:
New England Journal of Medicine
Research:Paper
Organisation/s: Telethon Kids Institute, Pfizer, USA, the MATISSE Study Group
Funder: Pfizer; MATISSE ClinicalTrials.gov number, NCT04424316.
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