COVID treatment drops 74% after vaccination

Vaccination reduced the number of severe coronavirus diseases requiring hospitalised treatment by an average of 74% (95% confidence interval 42%-88%) in the elderly and 84% (95% confidence interval 34%-96%) in the risk groups, according to the preliminary findings of research on the effectiveness of coronavirus vaccines in Finland.

The results are based on a register study carried out by the Finnish Institute for Health and Welfare (THL) based on the Care Register for Health Care, the National Infectious Diseases Register, and the National Vaccination Register, said the THL in a press release on Wednesday.

Vaccination data have been included for all people who have received at least one dose of the coronavirus vaccine. The effectiveness of the vaccines has been assessed separately in case of septuagenarians and those aged 16–69 in risk groups due to an already existing illness.

The study compares the risk of hospital treatment of coronavirus disease with that of those who have been vaccinated and of those who have not been. The assessment of the efficacy of the vaccinations has been standardised according to age, gender, the epidemic situation in the area, and whether the person vaccinated because his/her underlying diseases have put them in the first or second risk group to be vaccinated.

“Assessments of the effectiveness of vaccination are well in line with international results: the effectiveness after four weeks from receiving the first dose of vaccine has been 78% in Israel, 81% in Scotland, and 71-80% in England. The results depend, among other things, on the vaccine product used and the age of the subjects,” said THL Chief Physician Tuijab Leino.

All vaccine products used so far have been combined in the analysis. In Finland, the majority of mRNA vaccines have been administered to the elderly and the majority of adenovirus vector vaccines to those at risk.

Those who needed hospital care for coronavirus disease have been hospitalised within 10 days of contracting the infection on average. The effectiveness of vaccination to prevent hospitalisation has been assessed, when at least 30 days had passed since the vaccination.

“The effectiveness of vaccines may have been underestimated, since those who, due to health reasons, are the most fragile and who are likely to experience a lower efficacy of the vaccine, have received the vaccine first. However, the material is constantly supplemented and we will get more reliable results in the near future,” said Medical Specialist Eero Poukka.

All materials accumulated between 27 December 2020 and 28 March last have been included in the study. The results mainly concern the efficacy of a single dose of vaccine, as only one in 10 people who had received an mRNA vaccine had received another dose of vaccine during this period, whereas no one who had received an adenovirus vector vaccine had received a second dose.