Previous infection with omicron BA.1 or BA.2 subvariants protects vaccinated individuals four times more than BA.5 from non-infection. This is evidenced by a study from Portugal.

Previous infection with omicron subvariants BA.1 or BA.2 protected vaccinated people four times more than infection with Bachelor 5 from the absence of infection. This is evidenced by a study from Portugal. The research was published in the New England Journal of Medicine.

The researchers gained access to the national registry of Covid-19 cases. All SARS-CoV-2 infections have been recorded in the population aged 12 and over residing in Portugal. The virus type was determined for each infection taking into account the date of infection and the variable prevalent at the time.

Infection with omicron variants BA.1 and BA.2 protects against BA.5 .

“Vaccinated people who have been infected with the omicron BA.1 and BA.2 sub variants have about four times the protection from infection with the BA.5 variant, which has been circulating since June, compared to vaccinated people who have never been infected,” explains the joint study leader. Professor Luis Graça of the Joao Lobo Antunes Institute of Molecular Medicine and the University of Lisbon Medical School. Thus, infection with omicron variants BA.1 and BA.2 protects against BA.5.

Infections in 2020 and 2021 due to previous SARS-CoV-2 variants (alpha and Deltavariants) also confer protection against infection from the newer Omicron variant, although this protection is not as high. Protecting infected vaccines is called hybrid immunity.

Shows the benefit of adapted vaccines

The results are also important for the evaluation of vaccines that have been adapted to Omicron-BA.1 and allow for their usefulness to be projected, adds Luís Graça about the significance of the study. The corresponding vaccines have been available in Germany since September 5. Vaccines adapted to BA.4 and BA.5 have been approved as of October.

The usefulness of the second booster vaccination or the fourth vaccination is currently being discussed in Germany. This should not be done before six months after the last infection or vaccination. STIKO recommends them for people over 60 years of age and people over 5 years of age with an existing underlying disease. Since protection against a dangerous disease is particularly important, they should not postpone the date of a possible vaccination in order to wait for a vaccine that is better adapted to the variables currently in circulation.


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