How long will you be immune after catching Covid disease? How long does the vaccination protect? Do you have to be vaccinated again and again in order not to catch Corona? These are questions many people are currently asking themselves. And sure enough, some people anxiously received what the president of the pharmaceutical company Pfizer had just said: You might need a third vaccine from Biontech to be immune for a longer period.
“The likely scenario is that there would be a need for a third dose, somewhere between six and twelve months, and then an annual revaccination, but all of that has yet to be confirmed,” said Albert Paula, CEO of Pfizer. US CNBC in an interview.
An example of an annual revision of vaccines is the flu vaccination
Potential – and possibly annual – revaccinations have been discussed for a long time. It is also known from other viruses. From the influenza virus, for example. Here long ago it became normal. Because the protective effect of the influenza vaccination lasts about six to twelve months. In addition, the vaccine must be adjusted annually, since there are many strains of the virus: two strains of influenza A and B. The vaccine composition was based on the strain prevalent in the relevant influenza season. A quadruple vaccine has been in place in Germany since the 2018-2019 season.
Influenza viruses are also highly susceptible to mutations. They also belong to RNA viruses. Transcription errors are not fixed in the genetic material that appears during reproduction. Surface proteins change and subtypes arise. Researchers in Berlin-Charité recently said that influenza viruses are adept at evading the body’s immune response. They changed so quickly that the antibodies made by the immune system after a previous infection or vaccination were no longer able to recognize them well.
Charité researchers Comparison of a study in the specialist journal Virus Evolution The tendency for influenza and corona viruses to mutate. Because researchers have been watching for months: There are also stable mutations in the SARS-CoV-2 virus. They lead to various variants, of which, for example, the British variant B.1.1.7 currently prevalent in Germany appears to be more contagious than the previously circulating type.
Researchers have to constantly check whether existing vaccines are also effective against the new virus variant. As with the flu every year. Although it must be said that there is no one hundred percent protection. Even with the flu vaccination. If the vaccine is well adapted to the circulating influenza virus, a protective effect of up to 80 percent is observed in young adults, according to the RKI portal. In the elderly, who often have a limited immune response, the effectiveness is 41 to 63 percent. But despite current moderate vaccination rates, about 400,000 flu infections per year can be prevented in people over the age of 60. Sometimes this is especially important because of the dire consequences.
Vaccinations offer the elderly better protection than those that survive the infection
The protective effect of corona vaccines appears to be higher than that of influenza vaccines, at least if you take the manufacturer’s information. But studies seem to confirm this, too. A phase III study underway at Biontech shows that the vaccine is more than 90 percent effective for up to six months after the second vaccination, The manufacturer announced at the beginning of April. The message said there were no severe courses of Covid-19 – with hospitalization, intensive care, ventilation and death.
In Astrazeneca, the first vaccination is said to provide 76 percent three-month protection after the first vaccination, according to an Oxford study. The longer period between the first two vaccinations should increase the effectiveness – to 82.4 percent. Results of larger studies that lasted longer than six months are not yet available.
But what about immunity after infection with Corona? Shown here A study from DenmarkThat even a survivor’s Covid-19 disease does not reliably protect against renewed infection. The study, published in the Lancet specialist at the end of March, indicates protection from recurrent infection within six months for young adults at 80 percent, for people over the age of 65, however, only 47 percent – most likely due to no longer. immune system.
The Danish researchers concluded that people who had already contracted the Coronavirus should also be vaccinated. The researchers wrote: “All this data confirms that in the case of SARS-CoV-2, the hope for preventive immunity through natural infection may not be within reach, and that the global vaccination program with highly effective vaccines is the permanent solution.” Rosemary J. Boyton and Daniel M. Altmann of Imperial College, London, who were not involved in the study.
However, vaccination of infected persons should be taken into account “after six months of recovery at the earliest,” according to the guidelines of the Permanent Vaccination Committee (Stiko), in order to prevent excessive immune reactions. A single dose of the vaccine should be sufficient. But if you don’t even know if you are infected because some infections pass without symptoms, then a two-dose vaccination doesn’t hurt.
Researchers fear that the virus will become immune to vaccines
How long will the preventive effect of vaccination last – there are different estimates. Ranging from one to two years – or even more. Then it must be vaccinated again. However, this does not take into account after the coronavirus is mutating and it can penetrate the immune system for a vaccine. So it appears that the previous vaccines provide good protection against the British variant B.1.1.7, but may be less effective against the other ‘worrisome variants’. A study from Israel points to thisThat the South African variant B.1.351 can, to some extent, penetrate the immune defense created by Biontech vaccines.
There is currently concern that the virus will become immune to vaccination. At least against existing vaccines, which may be ineffective in a year or less. Fear of this Epidemiologists and virologists from 28 countries in a survey conducted by the People’s Vaccine Alliance, a consortium of nongovernmental organizations. The problem is the so-called immune escape variants. These escape variants can emerge as more and more people are vaccinated – but not enough to achieve herd immunity. The virus is under pressure of great choice. And there is a risk that the strongest viruses that are not recognized by the immune system will prevail.
The European Medicines Agency has already planned a procedure to allow for rapid approval of modified vaccines. The president of the Austrian Vaccine Manufacturers Association, Rene Gallo Daniel, said that existing vaccines can be changed within six to eight weeks so that they also work against mutations. Luca Sisen-Seine of the Helmholtz Center for Infection Research in Braunschweig said earlier vaccinations also continued to offer a certain level of protection. Because mutated viruses camouflage themselves, “viruses never become completely invisible.”
Prediction: It is likely that the ongoing adjustment of corona vaccines will not be necessary in the future
Charité researchers He dared to make a diagnosis in their studyBased on the understanding that the mutation rate of cold corona viruses is not generally as high as influenza viruses. While influenza viruses accumulate 25 mutations per 10,000 genetic components annually, corona viruses only have about six mutations, according to the researchers’ results. What is currently raising the rate is the epidemic caused by the newly emerging corona virus.
“If there are many infections, the virus can develop more quickly,” says Jan Felix Drexler, head of the study at the Institute of Virology. But: “On the basis of the development rates of the local cold Corona viruses, we assume that the SARS-CoV-2 virus will also change more slowly once the infection process subsides – that is, after receiving a large part of the world’s population,” says Drexler: “Immune protection has accumulated both through disease. Himself or through vaccination. ”So we assume that the Covid-19 vaccines will have to be checked regularly during the pandemic and adjusted if necessary.“ Once the situation stabilizes, it is possible that the vaccines will be usable for a longer period of time. ”In short: Perhaps the continuous adjustment of vaccines will not be Necessary.
Whether you will receive a vaccination at all will definitely depend on the consequences of Sars-CoV-2 in the post-pandemic phase. In any case, Pfizer chief Albert Paula thinks life can return to normal in late fall. His view of the future is like this: “Covid will be like some kind of flu. We will get the vaccine and live as normally as possible.”
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