Respiratory Syncytial Virus (RSV) Vaccine for Infants and Elders Gets EU Approval

European drug regulators have approved the region's first vaccine for the respiratory syncytial virus (RSV), which is the leading cause of hospitalizations in children. The vaccine called Abrysvo made by Pfizer was approved in the United States in May. This happened following the approval of GlaxoSmithKline’s anti-RSV drug called Arexvy last month. This new vaccine is designed to protect infants from birth through 6 months of age following the administration of the vaccine to the mother during pregnancy. This vaccine is also used for adults aged 60 years and older.

Respiratory Syncytial Virus (RSV): It's More Than Just a Cold

RSV is a common respiratory viral infection presenting mild, cold-like symptoms in children and adults. Most people recover within two weeks but it can cause serious health consequences such as bronchiolitis (inflammation of the small airways in the lung) and pneumonia (infection of the lungs), especially for infants and older adults (1^✔ ✔Trusted Source
Respiratory syncytial virus: from pathogenesis to potential therapeutic strategies

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Researchers recently estimated that respiratory syncytial virus (RSV) infection causes 160,000 hospitalizations every year in the European Union (EU). At 47%, the highest proportion occurred in people between 75-84 years of age, and nearly 92% of RSV hospitalizations were observed in older adults above 65 years.

RSV being a burden to nations, the quest for vaccines started many years before. The development began in the 1960s with an unsuccessful formalin-inactivated RSV (FI-RSV) vaccine that induced a fatal response. This response to natural RSV infection has been referred to as vaccine-associated enhanced respiratory disease (ERD).

The concerns over this response hindered the development of alternative RSV vaccines for many years. In recent years, increased understanding of the RSV and associated technological advances have resulted in the entry of multiple vaccine candidates into clinical trials.

Europe Approves New Vaccine to Protect Babies and Adults Against RSV

One among them is Abrysvo. It is a bivalent vaccine that gives protection against RSV A and B strains. The vaccine contains proteins essential for RSV to infect the body and are also the main targets of the antibodies generated to fight the infection. Abrysvo was evaluated under European Medicines Agency (EMA)’s assessment mechanism before entering the market.

Generally, the vaccine works by generating specific antibodies and T cells (immune system cells) that help prevent RSV infection. In the case of pregnant women, the antibodies cross the placenta to provide infants with protection up to 6 months after birth.

EMA’s human medicines committee (CHMP) assessed the working efficacy of the RSV vaccine based on data from two randomized, placebo-controlled, pivotal studies.

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In one study, 3,695 individuals at 24-36 weeks pregnant were administered Abrysvo while 3,697 received a dummy injection. The results showed that the vaccine was effective in reducing both lower respiratory tract infections occurring within 180 days after birth (2^✔ ✔Trusted Source
Efficacy and Safety of a Bivalent RSV Prefusion F Vaccine in Older Adults

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In the other study, 18,488 adults aged 60 years and older were administered the vaccine. The results of the study showed a reduction of RSV-associated lower respiratory tract illness with 3 or more symptoms.

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The most common side effects reported in vaccinated pregnant women between 24 and 36 weeks were pain in the injection site, headache, and muscle pain. In individuals above 60 years of age, the most frequently reported side effect was also pain.

The opinion adopted by the CHMP is the beginning step on Abrysvo’s path to patient access. The opinion will now be sent to the European Commission to decide its authorization for EU-wide marketing (3^✔ ✔Trusted Source
Meeting highlights from the Committee for Medicinal Products for Human Use (CHMP) 17-20 July 2023

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Once a marketing authorization has been granted, decisions about price and reimbursement will take place at the level of each Member State, considering the potential role/use of this medicine in the context of the national health system of that country.

References:

1. Respiratory syncytial virus: from pathogenesis to potential therapeutic strategies - (https://www.ijbs.com/v17p4073.htm)
2. Efficacy and Safety of a Bivalent RSV Prefusion F Vaccine in Older Adults - (https://www.nejm.org/doi/10.1056/NEJMoa2213836)
3. Meeting highlights from the Committee for Medicinal Products for Human Use (CHMP) 17-20 July 2023 - (https://www.ema.europa.eu/en/news/meeting-highlights-committee-medicinal-products-human-use-chmp-17-20-july-2023)

Source-Medindia