COVID booster not currently suggested for health workers

The Finnish Institute for Health and Welfare (THL) does not currently recommend the coronavirus booster vaccine available in late autumn for health and social services professionals who have no chronic illnesses, said THL in a press release on Monday.

The risk of contracting a severe coronavirus disease caused by the currently circulating Omicron variants is very low for previously vaccinated adults at working age with no chronic illnesses.

Not enough research evidence is available to support the administration of booster doses to health and social services professionals at the moment.

"Vaccines tailored to specific variants are recommended as booster doses to broaden the range of the immunological response. However, we do not yet know what level of protection they afford against infections compared to the original vaccine products, and what impact this might have on sickness absences", said Merit Melin, Research Manager of THL.

At best, protecting health and social services professionals against infections and infectiousness could also indirectly protect patients and residents at institutions providing long-term care.

However, the protection provided by the original coronavirus vaccine products against infections is only moderate and short-term, or a few months.

THL studies have found that a large proportion of the population have antibodies indicating a coronavirus infection. The proportion of those who have contracted the infection increased in spring and summer 2022.

THL examined the presence of antibodies in serum samples taken from children aged 1 to 17 at HUSLAB for reasons other than laboratory tests associated with COVID-19. Antibodies indicating a coronavirus infection were found in 73% of the samples taken in May.

The proportion of adults who have contracted the infection was assessed in a population study based on a random sample.

In March, antibodies indicating a coronavirus infection were found in 27% of samples from persons aged 18 to 84 who participated in the study in the hospital district of Helsinki and Uusimaa (HUS). In May–June, 35% of those who participated in the study in HUS hospital district and four other hospital districts had these antibodies. In younger age groups, a larger proportion of subjects had antibodies indicating an infection.

“As the proportion of infected persons grew to a significant level during the Omicron wave of spring 2022, especially in the youngest age groups, a very large share of those aged 12 or over have hybrid immunity formed as the combined effect of a coronavirus infection and vaccinations. Hybrid immunity is stronger and recognises a wider range of different virus variants compared to protection developed as a result of an infection or vaccination alone”, Melin said.

Some European countries recommend booster doses for health and social services professionals this autumn.

"No research evidence showing that variant-tailored products are more effective than reference products is available to support the decisions. The recommendations are based on a hope that variant-tailored products would be more effective in preventing infections", said Hanna Nohynek, Chief Physician of THL.

"THL issues its recommendations on booster vaccinations on medical grounds", Nohynek added.

If a health and social services professional belongs to the target group for booster doses in autumn 2022 due to their age or a chronic illness, a booster vaccine is recommended for them in the same way as for others in the same target group.

The THL recommended another coronavirus booster dose in late autumn for all those aged 65 or over, those aged 18 or over who are in medical at-risk groups, and those aged 12 or over with severe immunodeficiency.

People can take the booster vaccine when at least three months have passed since you had your previous vaccination or contracted the disease.

"Your previously formed immunity also affects the additional protection you obtain from the vaccination. If you had the previous vaccination or the illness a short period ago, such as a few months, you still have a good level of previously formed immunity. In this case, the response and additional protection against infections you gain from the booster dose may be minor", said Melin.

It is advisable to take the booster dose together with the influenza vaccine. Influenza vaccinations are usually administered in November–December. People should get the booster vaccine by the end of 2022.