Is it possible to get infected with COVID-19 twice
Experts answer 9 questions about re-covid
Is it possible to get COVID-19 again? The answer depends on how the situation with morbidity will develop further and the pandemic as a whole. After all, if we, having been ill, remain protected, then the number of new cases of infection will decrease. But the question remains open for now. Experts of the Bloomberg edition tried to figure it out. Based on the data already studied, they gave answers to 9 questions about repeated covid.
Repeated cases of COVID-19 are registered in the world. This is a proven fact. But there are far fewer of them than many people think, the researchers note, and add that the risk of re-infection is added by rapidly spreading new strains of the virus, first discovered in Britain, Brazil, India and South Africa.
1. How many people have been infected with COVID-19 repeatedly?
The Dutch news agency BNO New is counting suspected and confirmed repeated cases of COVID-19 worldwide. There are 72 of them – as of mid-April 2021. For comparison, the total number of confirmed "first" cases of COVID-19 exceeds 143 million.
Basically, repeated infections are detected in people with obvious symptoms of covid, experts say, but there may also be asymptomatic "covid-2" that are not detected.
Scientists in Denmark conducted a large-scale analysis of the results of repeated tests for coronavirus among about 4 million residents of the country. The study was published in the Lancet on March 17.
0.65% of people who tested positive for coronavirus during the first outbreak of COVID-19 in Denmark tested positive again during the second wave.
"The data are consistent with the results of studies in the UK, Qatar and the USA, which reported that re–infection occurs in less than 1% of cases," the researchers conclude.
2. Does this mean that most COVID-19 survivors are protected from reinfection?
Rather, yes, although the risk increases in elderly patients. The study showed that the level of protection for patients under 65 years of age is 80% or higher, and approximately 47% for people 65+.
3. Why is age a risk factor?
Researchers from Denmark believe that this is due to natural age-related changes in the immune system, the so-called "immune aging". As a result, older people become more susceptible to a number of infectious diseases.
4. How long does the immune defense against infection last?
The protective effect persists on average for seven months after the COVID-19. This is stated in the study, which was attended by more than 25 thousand health workers from Britain who were tested for coronavirus every two to four weeks. The study was published on April 9 in the Lancet.
5. Is re-infection something abnormal?
No. Only some viruses, such as those that cause measles, provide something close to lifelong protection against re-infection. SARS-CoV-2 viruses are widespread mainly because of their ability to infect repeatedly.
Factors that can contribute to re–infection are insufficient response of the immune system, weakened immunity and genetic mutations in the virus itself.
6. Do virus mutations increase the risk of re-infection?
Yes. In particular, two rapidly spreading strains of SARS-CoV-2 are called particularly contagious – these are P.1, discovered in Brazil in December and 501Y.V2, first recorded in South Africa in early August 2020. It is the Brazilian one that can most likely cause re-infection, experts of the publication note.
7. How to distinguish the case of re-infection from the manifestation of the prolonged form of the first?
If the PCR test shows a positive result, it does not mean that you have been infected again. This may be an extended form of the first infection. This is determined by the SARS-CoV-2 genetic test. Scientists "isolate" the pathogen, check its genetic fingerprint and find out whether the disease is caused by one variety of SARS-CoV-2 or different. If different, the infection is repeated.
8. What happens with the second infection?
A variety of options are described. There are severe cases of recurrent COVID-19, there are mild. And there is no difference whether you were seriously ill for the first time or not. Judging by the cases described, the severity of the disease after the second infection depends on the quality of the immune response to the primary infection, the interval between infections, the infecting dose of the virus (the maximum – in contact with the infected), the state of health of the infected person.
9. Will vaccines help?
The immune system needs to be well prepared to be as ready as possible to re-fight the virus. Vaccines are the best way to "teach" our body, and not only at the expense of antibodies. COVID-19 vaccines stimulate the production of lesser–known immune players - T cells. They play an important role in the acquired immune response.
Portal "Eternal youth" http://vechnayamolodost.ru