Vaccines against COVID-19 administered in the EU in the autumn of 2023 will be updated to target XBB forms of the SARS-CoV-2 virus. These strains are a subgroup of Omicron and have become dominant in Europe and other parts of the world. In particular, protection against XBB.1.5 was highlighted by experts as being a priority.
Last year, the European Medicines Agency (EMA) recommended omicron boosters ahead of an anticipated ‘winter wave’ of COVID-19 cases, while the EMA’s Chief Medical Officer told Vaccines Today in September that the approach taken to adapting COVID-19 vaccines would probably mirror that taken to updating the annual flu vaccine.
This has proven to be the case and, while the WHO has recently said that COVID-19 is no longer a ‘public health emergency of international concern’, some vulnerable groups will be advised to have an updated COVID-19 booster along with their annual flu vaccine.
How many doses are needed?
The existing range of vaccines continue to be effective in preventing hospitalisation, severe disease and death due to COVID-19, according to a joint statement by the EMA and the European Centre for Disease Prevention & Control (ECDC). However, protection against the virus declines over time, particularly as new variants emerge.
A single dose of the adapted vaccine is considered sufficient for individuals above five years of age. For younger children who have never been vaccinated and have not been infected with the virus, a two or three-dose series of vaccines is advised.
People with weakened immune systems may need additional doses in line with national recommendations, European authorities said.
There should be a minimum of three months between vaccines. However, a four-month interval between doses can be considered, given the evidence showing that protection against severe disease lasts for at least four months.
Who is a priority for autumn vaccines?
The ECDC and EMA advise that the vaccination campaigns ahead of the autumn should prioritise people who are more at risk of having severe disease. These include people aged 60 years and above, people with weakened immune systems and underlying conditions putting them at higher risk of severe COVID-19 irrespective of age, and those who are pregnant.
Vaccination of healthcare workers should also be considered because of their likely increased exposure to new waves of SARS-CoV-2 and their key role in the functioning of healthcare systems.
‘Timely vaccination ahead of a potential autumn and winter 2023 surge of COVID-19 cases is essential for protecting people from severe COVID-19 and health systems from being overwhelmed,’ the authorities said in a joint statement.
