Why you should be vaccinated even if you have already had Covid-19 – ScienceNorway

Vaccines help boost the production of antibodies, providing effective protection against serious illness and death, Mona Hyster Fenstad says.

She is a senior consultant at the blood bank at St. Olavs Hospital in Central Norway.

The Covid-19 virus is rife all over Norway. The Norwegian Institute of Public Health recommends people in risk groups to get vaccinated.

They point out that elderly people in particular will be vulnerable to serious illness if they are infected with Covid-19. However, since the vast majority of us have already had Covid-19 at least once, do we really need to think about getting vaccinated?

Yes, the scientists say.

The saying what doesnt kill you makes you stronger is not true in this context. The inflammation that occurs in the body during infections such as influenza, Covid-19, and pneumonia can be harmful. Especially for people with heart or lung disease, or where other risk factors are involved, Fenstad says.

Fenstand and her international colleagues have recently published a study that looked at the effect of vaccination on people who became ill with Covid-19 before vaccines were available. This work has been closely linked to the search for antibodies that can be used as medicine against Covid-19.

At the beginning of 2020, the World Health Organization (WHO) asked scientists and therapists around the world to look for treatments for Covid-19. Among the treatments proposed was convalescent plasma therapy, which uses plasma from blood donors who have recovered from the illness," Fenstad says.

Along with NTNU colleagues, the researchers chose to take a closer look at how the antibodies in this plasma were able to neutralise new virus variants that emerged.

While big pharmaceutical companies were working hard to develop vaccines and medicines, researchers had already begun to look at the use of blood plasma from Covid-19 patients as a possible treatment.

Many of these patients had large amounts of antibodies in their blood. Plasma containing these antibodies was therefore given to seriously ill patients to help them fight the virus. It turned out that convalescent plasma therapy was primarily effective in patients who had immunodeficiencies, Fenstad says.

We were looking for so-called super-neutralisers, people who develop specific antibodies that effectively neutralise different variants of SARS-CoV-2, Denis Kainov says. He is a professor in NTNUs Department of Clinical and Molecular Medicine, and was part of the research team.

These antibodies were eventually cultivated and cloned, and then turned into medicines used to fight Covid-19.

In Norway, the first Covid-19 outbreak occurred in February 2020. The first Alpha variant was quickly followed by new, mutated variants named Beta and Delta. Omicron, which is currently the prevailing variant, was first reported in late 2021.

By April 2020, blood banks across Norway had begun collecting blood plasma from patients who had recovered from Covid-19. At St. Olavs Hospital, 72 patients were selected for a more detailed study of the antibodies in their blood plasma.

It turned out that half of these patients had serum containing antibodies that effectively neutralised the Beta variant, Kainov says.

Kainov has been searching for active substances to use in the treatment of Covid-19 and other viral diseases.

He is now looking for antibodies that could provide wider protection, including against new Covid-19 variants that might emerge.

They noticed that four patients had antibodies that effectively neutralised the Covid-19 variant that was dominant in Trondheim, Central Norway, at the time.

We followed up by taking new samples from these patients and found that their antibodies also neutralised other Covid-19 variants. In fact, they were also effective on new virus variants, Kainov says.

The conclusion is thus that it is a good idea to get vaccinated even if you have already had Covid-19 and even if the virus has mutated since the vaccine was made.

Out of the four patients, the researchers picked the one whose antibodies had been least effective against the Omicron variant. This patient had received their first vaccine dose four months after recovering from Covid-19. The efficacy of the vaccine was striking.

The vaccine boosted the production of immune cells and antibodies against all tested variants of the virus, including Omicron, Kainov says.

Kainovs colleagues in Estonia could then proceed with blood plasma from the patient, cloning and cultivating antibodies that neutralised Covid-19 viruses on a wide scale.

The results have also provided the scientists with useful knowledge about the effect of the vaccine on convalescents.

When it comes to vaccines, it is always a race. The virus is always one step ahead, and the vaccines and medicines will never be completely up to date, Fenstad says.

Their study is an in-depth study of just one patient, and it constitutes only a tiny piece of research in this field.

"However, large studies in other countries confirm our findings. Vaccines boost the production of antibodies that are also effective against new variants of the virus, she says.

The finding demonstrate that it is a good idea to get vaccinated even if you have already had Covid-19 and even if the virus has mutated since the vaccine was made. It may not prevent you from being reinfected, but it will provide protection against serious illness and death.

When you get sick with Covid-19, you develop antibodies, but the effects of these diminish and are gone after six to nine months. This is why people can get infected again and again by new variants of SARS-CoV-2. The virus mutates to avoid the immune response we have developed through previous infections or vaccines, Kainov says.

That is why vaccination is important now that it is winter.

The studies we have conducted here on Covid-19 patients are extremely important, because there will be new outbreaks of the virus. Almost seven million people have died from Covid-19. We must avoid getting into the same situation again, Kainov says.

Reference:

Fenstad et al. Boosted production of antibodies that neutralized different SARS-CoV-2 variants in a COVID-19 convalescent following messenger RNA vaccination a case study, International Journal of Infectious Diseases,2023.

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Why you should be vaccinated even if you have already had Covid-19 - ScienceNorway