Respiratory viruses and infection control

Lorna Rothery, from Health Europa, spoke to Dr Albert Osterhaus, expert virologist and Chairman of the European Scientific Working group on Influenza and other Respiratory Viruses about the burden of respiratory infections.

Founded in 1992, the European Scientific Working group on Influenza and other Respiratory Viruses (ESWI) endeavours to reduce the burden of respiratory illnesses by facilitating cross-disciplinary research and communicating with key stakeholders to raise awareness and improve public health. Lorna Rothery spoke to the ESWI’s Chairman and leading virologist Dr Albert Osterhaus about how COVID-19 has influenced the circulation of respiratory viruses and the key measures that could be taken to mitigate the threat of viral epidemics and pandemics.

What influence has the COVID-19 pandemic had on the circulation of the influenza virus, respiratory syncytial virus (RSV), and possibly other viruses? What implications could this have during the flu season?

In countries where serious measures were taken during the pandemic, we saw a significant reduction in annual infections. We barely had any influenza in Europe, as a result of the preventive non-pharmaceutical intervention measures in place such as mask-wearing and social distancing. This is true for flu and RSV also and has been the case in many countries where systematic monitoring of the virus and infection took place.

Interestingly, there was an RSV outbreak among children in the middle of the summer, during the first relaxation of COVID measures, which we had never seen before. This showed that viruses like RSV and influenza were knocking on the door. We know that influenza and RSV, and typically other seasonal coronaviruses, usually hit in the winter months for several reasons. There has been a lot of speculation that since influenza has been away now for quite some time, and vaccination levels have dropped considerably, we may expect a very serious influenza season. There is no reason to believe that there will not be a serious influenza virus outbreak, as we have seen in previous years, but we predicted pandemics of H5 and lots of other things, and we have to be careful with those predictions.

Many European countries, including Germany and the Netherlands, are dealing with outbreaks of RSV among young children and the question is, will this affect older adults as well and are countermeasures against RSV for this age group necessary? Within the next couple of years, there will be new RSV vaccines; we have to continue to vaccinate against flu, COVID-19 and then RSV when vaccines are available.

It is important that the most vulnerable members of society, including older adults and children, are vaccinated, but this also calls into question vaccine hesitancy and affordability. Many countries in Europe do not reimburse for influenza vaccination and if RSV and COVID come on top of that, we are facing an extra problem. Additionally, we need to consider the frequency of vaccinations against viruses; ideally, you would have one vaccine to protect you against multiple viruses like flu, RSV and COVID.

There are other acute respiratory viruses too including metapneumovirus (hMPV), which was discovered at the turn of the century but has been amongst us for hundreds of years. We know it spilt over from a bird reservoir and that one is knocking on the door as well. So, it might be that we combine the RSV and hMPV vaccines and there are discussions taking place on how to do this and who is going to deliver that. In many countries, the COVID vaccines are not administered by GPs, there are municipal or national programmes to do that. However, the flu vaccines in most European countries are being given by the GPs and they have a special scheme for that.