Travel restrictions on COVID-19 and public health measures have led to a change in the genetics of respiratory syncytial virus (RSV), a common winter virus in Australia, according to a new study. The study, published in Nature Communications, is one of the first. to document the impact of COVID-19 on viruses already existing in Australia.
The investigation found that RSV disappeared for the first time in history recorded during 2020, but made a rapid resurgence in the summer of 2020 to 2021 after border restrictions and health measures were lifted.
Electron micrograph of human RSV virions, represented in blue. (National Institutes of Health)
Following the outbreaks in Western Australia, New South Wales and the Australian Capital Territory, researchers genetically sequenced the virus “out of season” and found various changes in its genetic code.
All but one of the previous strains of RSV have been “extinguished,” the lead researcher Dr. John-Sebastian Eden of the Institute of Infectious Diseases at the University of Sydney issued a warning.
In this June 2021 photo, a six-week-old boy, Beau, is in a hospital bed in Matoon, Illinois. Beau developed a strong cough after his church dedication ceremony. Her mother, who has a medical history, was suspected of having respiratory syncytial virus when she opened her stretcher and saw that her chest was shaking with a hard breath. (LaRanda St. John via AP) (LaRanda St. John via AP)
“For each outbreak only one genetic lineage had survived all the blockages,” Eden said.
“We need to be careful: some viruses may have almost disappeared, but they will probably recover in the near future, possibly at unusual times and with a stronger impact.
“We need to be prepared for large outbreaks of RSV outside of normal seasonal periods and our health systems are ready.”
There is currently no vaccine against RSV, which is highly contagious.
The virus infects the airways and lungs, and although it usually causes mild, cold-like symptoms, the infection can be severe, especially for babies and older adults.
Cases of colds and flu have skyrocketed in Victoria and NSW in recent weeks. (iStock)
The number of known cases of flu reported in Victoria this year rose from 10,000 to 15,000 last week, while in NSW there were 1,140 cases of respiratory illness last week, compared to 766 the previous week.
The study raises questions about how the rapid spread and evolution of RSV could report the recurrence of other viruses, including the flu.
Australia opens the first day of winter with heavy snowfall
“The constellation of flu strains circulating before and after COVID-19 has also changed a lot, which has led to challenges in how we choose the composition and timing of our annual vaccines,” Eden said.
“For example, the flu season in Australia has started much earlier than in previous years.”