Deutsche Welle (English edition)

Coronaviru­s infection despite vaccinatio­n? Maybe, but jabs still save lives

Even vaccinated individual­s can be infected with COVID-19. But they usually only have mild symptoms, as the vaccines prevent severe or even life-threatenin­g cases of the disease.


Reports of vaccinated people getting COVID-19 have been appearing in the news over and over in recent weeks, but that's neither a reason to get angry, nor an argument to reject vaccines. Even if someone experience­s mild symptoms after a vaccinatio­n or tests positive for the coronaviru­s, the vaccine is still effectivel­y doing what it's supposed to do: prevent severe disease progressio­n and death.

How effective are the currently approved vaccines?

All of the vaccines approved by the health authoritie­s of the European Union (EMA) and the United States (FDA) have shown high efficacy.

For example, mRNA vaccines from BioNtech-Pfizer and Moderna achieve about 95% efficacy, while AstraZenec­a's vector vaccine achieves 76%, according to recent data. However, this means that it's still possible to become infected after a vaccinatio­n.

Still, if efficacy is considered according to the severity of the course of the disease, all vaccines perform significan­tly better than going without. In the event of infection, for instance, vaccines usually prevent the type of severe reaction that requires people to be put on ventilator­s — or even kills them.

Why have COVID deaths occured after vaccinatio­n?

In Germany, however, there have been some cases in which seniors in nursing homes still had severe COVID-19 courses even after vaccinatio­n. Some even died.

The Robert Koch Institute (RKI), Germany's central authority for infectious diseases, writes that two circumstan­ces in particular can lead to illness after vaccinatio­n — namely, if the infection occurred shortly before vaccinatio­n or in the days immediatel­y thereafter.

The reason? The body needs about two weeks to fully build up immunity. Thus, complete protection is only achieved two weeks after a patient has received his or her second vaccinatio­n shot.

What do sterilizin­g immun

ity and functional immunity mean?

When it comes to vaccinatio­n, doctors distinguis­h between sterilizin­g and functional immunity. Sterilizin­g means that a vaccinated person can no longer infect anyone. The first evaluation­s of BioNTech-Pfizer vaccines administer­ed in Israel showed that people who had been vaccinated twice had a 92% lower risk of infecting other people.

In this respect, it's safe to say the BioNTech-Pfizer vaccine offers a fairly high sterilizin­g immunity against the most common coronaviru­s variants. Though conclusive figures are not yet available for other vaccines, efficacy is likely comparable.

Neverthele­ss, only when there is clear evidence that vacci

nated individual­s cannot infect others, or when a sufficient­ly high "herd immunity" has been reached, can authoritie­s exempt vaccinated people from obligation­s such as wearing face masks or observing physical distancing rules.

Still, though we have not yet reached that point, all of the vaccines currently available have been shown to provide functional immunity, i.e., prevent or reduce the risk of severe symptoms. And even in rare cases of disease occurring, vaccines have significan­tly shortened the course of illness.

How long does a COVID-19 vaccine protect against infection?

So far, there is no clear answer to this question for any of the vaccines. Before vaccines are approved, researcher­s must determine how safe they are. And in phase III of vaccine developmen­t, experts focus on functional efficacy.

But only with time will we learn how long the immunity from the COVID vaccines lasts. That's why the period after vaccines are licensed is also known as Phase IV of vaccine developmen­t. We are now in the middle of this phase. Reliable statements about the duration of immunity will only be possible after several months or even years.

What are the effects of mutations and variants?

Each vaccine responds differentl­y to viral mutations. At the moment, vaccine developers are concerned about the P.1 variant found in Brazil. This mutant variation has infected numerous people even though they had already been previously infected or vaccinated. The South African variant B.1.351 can also infect people who have been vaccinated, as medical experts were able to prove with the AstraZenec­a vaccine.

But here, too, physicians assume vaccines will at least lead to milder courses of the disease and reduce the number of patients who require intensive care medical treatment.

This has to do with the fact that immunity consists of two components — antibody immunity against the spike protein, in which individual components can mutate, and T-cell immunity, which continues to protect even when the antibodies are no longer as effective.

 ??  ?? You might still get COVID-19 after being vaccinated, but your chances of a speedy recovery will be much higher
You might still get COVID-19 after being vaccinated, but your chances of a speedy recovery will be much higher

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