Most European Union/European Economic Area (EU/EEA) countries have detected low proportions of the SARS-CoV-2 variants BA.4 and BA.5, however many have seen an increase in recent weeks. In Portugal, BA.5 has become the dominant SARS-CoV-2 variant and the increasing proportions of BA.5 have been accompanied by a surge in Covid-19 cases. The growth advantage reported for BA.4 and BA.5 suggest that these variants will become dominant throughout the EU/EEA, probably resulting in an increase in Covid-19 cases in coming weeks.
The extent of the increase in Covid-19 cases will depend on various factors, including immune protection against infection influenced by the timing and coverage of Covid-19 vaccination regimes, and the extent, timing and variant landscape of previous SARS-CoV-2 pandemic waves. Based on limited data, there is no evidence of BA.4 and BA.5 being associated with increased infection severity compared to the circulating variants BA.1 and BA.2. However, as in previous waves, an increase in Covid-19 cases overall can result in an increase in hospitalisations, ICU admissions and deaths.
Countries should remain vigilant for signals of BA.4 and BA.5 emergence and spread; maintain sensitive and representative testing and genomic surveillance with timely sequence reporting, and strengthen sentinel surveillance systems (primary care ILI/ARI and SARI). Countries should continue to monitor Covid-19 case rates - especially in people aged 65 and older - and severity indicators such as hospitalisations, ICU admissions, ICU occupancy and death.
Improving Covid-19 vaccine uptake of the primary course and first booster dose in populations who are yet to receive them remains a priority. It is expected that additional booster doses will be needed for those groups most at risk of severe disease, in anticipation of future waves.