[ad_1]
A full REACT-2 study by British researchers from Imperial College London shows that people infected with the coronavirus appear to lose antibodies much faster than previously thought.
Researchers, on behalf of the British government, studied the level of antibodies in a population of 365,000 people in the UK after the first wave broke in March and April, between June and September.
In total, the level of antibodies in the population sample dropped by as much as 26 percent after a period of three months, the study shows.
– Measurements will last a long time
Great fall
The study found that the level of antibodies in the population sample fell most rapidly within the first six weeks of the period. Here are some of the key findings:
Therefore, it can be difficult to achieve herd immunity with a vaccine that develops antibodies, the study shows. If such a vaccine hits the market, it may mean that you have to take it multiple times, up to every six months, to get an effective level of antibodies again to achieve the effect, the researchers say.
The researchers make a reservation that it is not known how long one can be immune and how strong the immunity is after infection. Their study also does not address how other factors may play a role, such as T cells, white blood cells that find virus-infected cells and kill them, which may also be crucial in strengthening the body’s immune response. It is not peer reviewed.
Bad news for vaccines
The fact that people infected with the coronavirus appear to lose their antibodies much faster than previously thought may be bad news for some favorite vaccines.
Candidates for pharmaceutical giants AstraZeneca, which collaborates with the University of Oxford and American Johnson & Johnson, are among those who have made the most progress in developing a vaccine. Both have completed phase 2 trials and are relevant to Norway, of which the former has applied for approval from the European Medicines Agency (EMA).
They develop so-called viral vector vaccines, which deliver a modified and less dangerous virus to the body to establish a controlled infection. It should cause the body to make antibodies.
Vaccine in early April
But don’t the British researchers’ findings mean that flock immunity is difficult to achieve by eliciting antibodies, if these disappear quickly? Both yes and no, says Gunnveig Grødeland, a researcher at the Department of Immunology and Transfusion Medicine at the University of Oslo.
– This may show that we need to shift the focus from antibodies exclusively to a stronger T-cell response. We need to start thinking more broadly when it comes to vaccines. What T cells can do is kill cells that are infected with the virus and thereby control and clean up a viral infection, Grødeland tells Dagbladet’s “Right on” podcast.
Listen to the full episode here:
If we do not get an effective vaccine, what is applied is the continuation of the measures, says Grødeland.
– What we have seen so far is that it is very difficult to achieve herd immunity. If it had been easy, we would have seen immunity in regions that have been the epicenter of the coronavirus. We don’t, sadly, she says.
Health Minister Bent Høie (H) previously told Dagbladet that “it can affect the lives of all of us if we do not achieve herd immunity.”
– So those who are in risk groups must live with the danger that they can become seriously ill and in the worst case die, while those of us who are not in risk groups must live with restrictions in daily life. A vaccine can help all of us return to a more normal and safe life, Høie said.
Therefore, vaccine candidates are discontinued.
NIPH: You must wait a significant duration
Geir Bukholm, director of infection control and head of vaccine work at the Norwegian Institute of Public Health (NIPH), has seen the REACT-2 study by the British researchers. He says that the level of antibodies is known to drop quite quickly after a natural infection. This is because of how the active SARS-CoV-2 virus affects our cells in the body, including our immune systems, he says.
– Most vaccines that are in development do not contain all of this virus, but only individual proteins that the virus can produce. Therefore, there is not necessarily a connection between immunity after natural infection and immunity after vaccination with a good vaccine, Bukholm tells Dagbladet.
see more
In a dark winter
So far no vaccines have been approved. Knowledge of how effective individual vaccines are will only be available when the results of “effects” studies (phase 3 studies) are available. These results will be available around the time the vaccines receive a marketing authorization from the EMA / Norwegian Medicines Agency, Bukholm notes.
– May it be necessary to get vaccinated regularly or several times to be effective?
– Most of the vaccines in development are planned to be given in two doses with 3-4 weeks between each dose. A good vaccine is expected to provide immunity for a considerable duration after the second dose has been administered, but we will only know how long immunity lasts when the results of studies measuring the effect of vaccines are available.
– A completely different virus
How SARS-CoV-2 affects the immune system is not fully understood. This explains why Bukholm applies both to the importance of immunity through antibodies and to so-called cellular immunity (T-cell immunity) after natural infection. Therefore, we do not know the importance of natural infection for herd immunity.
When asked by Dagbladet if a viral vector vaccine developed by leaders AstraZeneca and Johnson & Johnson is effective if the antibodies disappear after a few months, the director of infection control responds:
– The mentioned study says something about how fast antibodies follow natural infection disappears. The study says nothing about how old it is antibodies after a vaccine.
Don’t wash face masks like this!
He continues:
Viral vector vaccines contain a virus, in this case an adenovirus, which is a completely different virus than the virus to be vaccinated against. This adenovirus has been given the gene for a protein (and only this one!) From SARS-CoV-2. Such an effective adenovirus vector vaccine will ensure that our immune system produces antibodies (“neutralizers”) and cellular immunity to this protein, which is supplied by SARS-CoV-2. The goal of such a vaccine concept is that this adenovirus vaccine should not contain the properties of SARS-CoV-2 that weaken the immune response (and make the antibodies disappear quickly). But as stated above, how effective such a vaccine is, we only get information about when vaccine test results are available.
