Structure Polish Academy of Sciences

It is our behavior that will determine how severe the fourth wave of COVID-19 infections will be and whether it will paralyze the health-care system. Therefore, the current lull should not cause us to relax our vigilance.

What will the fourth wave be like?

Since mid-May 2021, we have watched the third wave of the pandemic fade away in Poland, with a significant drop in COVID-19 infections, hospitalizations, and deaths. This situation is due to not only to recent severe social contact restrictions, but also to the growing number of vaccinated individuals. The weather is favorable: it’s warmer, so we are spending a lot of time outdoors and making sure that indoor spaces are ventilated frequently. Social and economic life has largely returned to normal: schools, restaurants, sports facilities, and cultural institutions have reopened, and the limits on the number of guests for social gatherings and events are very high.

The Poles are starting to hope that the pandemic is ending for good. However, we should be prepared for a much more difficult scenario. In Poland, the re-opening of the economy and the resumption of social life combined with insufficient vaccination rates and the appearance of a new and more contagious variant of the virus may contribute to a surge in the pandemic, thus triggering a dangerous fourth wave of infections. First detected in India, this more contagious variant, called the Delta variant, has already become dominant in such countries as the UK, and it is beginning to spread among our population.

It is our behavior that will determine how severe the fourth wave will be and whether it will paralyze the health-care system. Therefore, the current lull should not cause us to relax our vigilance.

The dangerous Delta variant

Studies of the Delta variant show that it is more contagious than the Alpha variant (also called the British variant), which dominated the third wave of infections in Poland in March and April 2021. The Delta variant is estimated to be up to twice as contagious as other variants, so it can completely dominate the variants previously circulating in a given population in a matter of two months. In the UK, the Delta variant is now responsible for 90% of new infections and has caused the number of new cases detected there to rise fivefold in less than four weeks.

At the same time, the number of COVID-19 hospitalizations and deaths in the UK remains stable and very low, which results from relatively high vaccination rates. In the UK, 65% of the population have had at least one vaccine dose (compared with 44% in Poland), and over 48% (versus 33% in Poland) have been fully vaccinated (data as of 26 June 2021). This also results from the fact that most of older people (aged 60+) in the UK have already been vaccinated. The disease continues to spread, but its death toll is now much lower. Unfortunately, the situation in Poland may look a lot more dramatic.

Data indicate that the Delta variant mostly strikes those who have not been vaccinated – they account for more than two-thirds of all new cases. By contrast, those who are fully vaccinated remain highly immune.  Being fully vaccinated significantly reduces the risk of illness and very significantly reduces the risk of hospitalization in those who have contracted the disease. This has been shown by studies conducted by Public Health England / UK Health Security Agency for the viral vector vaccine (AstraZeneca) and the mRNA vaccine (BioNTech/Pfizer). There’s much to indicate that the same will hold true for other vaccines that have been granted marketing authorization.

There is also a growing number of studies showing that even if vaccinated individuals become ill, they are considerably less likely to infect those they live and interact with on a daily basis than those who have not been vaccinated.

What can we do to protect ourselves and our loved ones?

The Delta variant is already present in Poland. The first isolated cases were recorded in late April. Currently, this variant already accounts for several percent of all infections, and it’s spreading at a growing rate. We can assume that in September it will become the dominant variant in the whole of Poland. Its high contagiousness combined with the re-opening of the economy and low full vaccination rates (especially in at-risk groups) means that the Delta variant poses a much greater danger to Poland than to such countries as the UK. The Delta variant in Poland may prompt new lockdowns.

Whether we succeed in limiting the transmission of the virus and therefore avoid a severe fourth wave of infections depends largely on our behavior in the coming weeks. For this reason, we appeal to everyone to observe a few simple rules:

1. Meet outdoors with large groups of people; avoid closed spaces and crowds.
2. Postpone attending and organizing meetings until all participants are fully vaccinated – vaccine availability is now high in Poland, so everyone can book a vaccine appointment in just several days.
3. Remember to ventilate indoor spaces regularly. Wear a mask in the presence of unvaccinated people or if you’re not sure that everybody around you has been vaccinated, for examples in stores, at work, or at church.
4. Make sure you and your loved ones become fully vaccinated this summer. Acquired immunity will help us avoid a severe fourth wave of infections and prevent schools, stores, restaurants, hotels, theaters, museums, movie theaters, and churches from being closed again. Vaccines are currently available to everyone over the age of 12. In order to stop the transmission of the Delta variant and avoid new lockdown measures, children and adolescents should be vaccinated before they go back to school. Act now to make sure that your children are vaccinated.
5. Rest and take care of your mental health. Staying in good condition and mentally resilient will help you to cope better with the fourth wave of the pandemic.
6. Choose your holiday destinations carefully, avoiding those where the number of infections is on the raise (to avoid problems with returning home) and above all those characterized by the presence of more contagious variants of the virus. When the virus travels long distances, it does so inside our bodies – let’s not make it easier for it to reach Poland.
7. Get tested as soon as possible even if you only have mild symptoms. The epidemiological situation is currently good, and it can be maintained by carrying out tests, isolating those who have been infected, and quarantining the unvaccinated individuals who have had contact with the virus. Diagnostic tests are a necessary first step to effectively monitor the status of the pandemic, including detecting and controlling the first outbreaks of the new variants of the virus. Falling ill may spoil individual holiday plans, but a failure to control the pandemic more generally will necessitate renewed nationwide restrictions that will affect everyone.

We appeal to the local authorities, local communities, and local organizations, such as rural women’s associations, parish communities, and the Voluntary Fire Brigades to support and promote the vaccination campaign and ensure easier access to vaccination sites for the elderly. If you’ve had a vaccine because you’re convinced this is the right choice, try to persuade others to do the same during the summer vacation.

This summer, we have a unique opportunity to learn from the past experience in the fight against the pandemic. We know that the highly contagious Delta variant is already present in Poland, and we can’t rule out the emergence of other new variants. We should not repeat the mistake we made a year ago and believe that the virus is in retreat. We have a year of experience more, with science and vaccinations being on our side in the fight against the virus. What our summer and autumn will look like depends on our own actions.

About the team

The Interdisciplinary COVID-19 Advisory Team to the President of the Polish Academy of Sciences was set up on 30 June 2020. The team is chaired by Prof. Jerzy Duszyński, President of the PAS, with Prof. Krzysztof Pyrć (Jagiellonian University) as deputy chair and Dr. Anna Plater-Zyberk (Polish Academy of Sciences) as its secretary.

Other members of the team are:

• Dr. Aneta Afelt (University of Warsaw)
• Prof. Małgorzata Kossowska (Jagiellonian University)
• Prof. Radosław Owczuk, MD (Medical University of Gdańsk)
• Dr. Anna Ochab-Marcinek (PAS Institute of Physical Chemistry)
• Dr. Wojciech Paczos (PAS Institute of Economics, Cardiff University)
• Dr. Magdalena Rosińska, MD (National Institute for Public Health – National Hygiene Institute, Warsaw)
• Prof. Andrzej Rychard (PAS Institute of Philosophy and Sociology)
• Dr. Tomasz Smiatacz, MD (Medical University of Gdańsk)