O new variant B.1.1.529, nicknamed omicron, has spread across the planet and new countries announce their detection with each passing day. While aspects such as its greater transmissibility are being investigated, the big question is one that surrounds its relationship with vaccines. Several experts respond.
How will we know if vaccines resist omicron?
“To find out, it is necessary to isolate the variant and compare it with sera from patients who have been vaccinated or infected with the virus (preferably with different variants)”, he says. Sonia Zuniga, virologist at the National Center for Biotechnology (CNB-CSIC)
“In this way it is possible to know the ability to neutralize the virus by the response of antibodies generated by vaccines. In order to have information about the efficacy, it will be necessary to spend more time and see in the epidemiological data, at a population scale, whether the efficacy of the doses was maintained or decreased”, he adds.
The fastest test to find out if there is resistance or not is to use the serum of individuals immunized with the vaccines and face them with omicron. This will indicate whether these antibodies have the ability to neutralize the virus or not.
Ignacio J. Molina (UGR)
The same explains the professor of Immunology at the University of Granada (UGR), Ignacio J. Molina: “The fastest test to find out if there is resistance or not is to use the serum of individuals immunized with the vaccines (with antibodies against the original variant, which is used as an immunogen) and face them with the micron. This will indicate whether these antibodies are capable of neutralizing the virus or not”.
“If they neutralize, the vaccines will likely be effective. This must be corroborated by another more complex test to measure the cell immunity. We will also need epidemiological data, which will tell us whether people vaccinated are more infected with the new variant”, he highlights.
How long will it take to find out?
According to Africa Gonzalez, Professor of Immunology at University of Vigo, “The laboratory data may take a few weeks, as we already have sera from immunized people and we can be tested against the new variant.”
Molina thinks the same: “The antibody test is relatively fast, we could have data in two or three weeks. The study of cellular immunity is a little slower, it can take a few months. For the study of infectivity in people it will take longer, probably about half a year”.
Less specific is Jose Jimenez, researcher of King’s College London: “It will take a while to figure out why the omicron variant is still so much in the minority. To get reliable data, you need to have a larger sample, and that’s something we don’t know if it’s going to happen. Of course, sooner we will have data in vitro of the neutralizing power of antibodies generated with vaccines”.
How to interpret the first data obtained in the laboratory
For the specialist who works in the UK, “these data will be important and will indicate whether this new variant has the potential to evade, at least partially, the antibody response. However, if that happens, it doesn’t mean that the same will happen to people; we can’t forget that the immune response it is much more than just generating antibodies”.
The immune system has already seen a ‘picture of the enemy’ with the vaccine and the infection, and even if it changes, it will continue to recognize it. Coronavirus variants do not change so drastically to lose all immunity
Africa González (Uvigo)
Likewise, González highlights how the data in vitro they cannot be completely extrapolated to reality. “The immune system is very complex. I show it as an army of different soldiers (ready sentries, with different weapons, and also elite soldiers). And in laboratories, it is customary to study only total and neutralizing antibodies”.
The fact that antibodies slightly diminish the recognition of a new variant does not always have to be directly reflected in the reality of infected people, as we are not watching the action of other ‘soldiers’. “Seeing the new virus, our immunity system also learn again. So the only real evidence will be to see the effectiveness in preventing serious illnesses, hospitalizations and deaths in people. For that, epidemiological data will be fundamental”, he insists.
What can we expect with the data available today?
“The variant is worrisome because it contains a higher number of mutations in the spike protein and, in addition, many of them are concentrated in the area of attachment to the cell receptor. At least theoretically, it is possible that the properties of the virus have changed in terms of its entry into cells and the ability of antibodies to block the infection”, emphasizes Sonia Zúñiga.
In any case, the virologist makes it clear that in biology it is not easy to predict the effect of so many changes combined and we must wait for the experimental results. Furthermore, data is still scarce and little representative, as currently most of those infected were identified in Africa, where the percentage of the vaccinated population is low compared to other places.
The variant is of concern because it contains a greater number of peak protein mutations. But in biology it is not easy to predict the effect of so many changes combined and we must wait for the experimental results. Furthermore, data are still scarce and unrepresentative.
Sonia Zuñiga (CNB)
“It is likely, as with other variants, that the neutralizing capacity of existing vaccines is lower. But it’s possible that this lesser neutralizing capacity is even more than enough to protect us from developing serious illness. That’s what happened, for example, with the delta variant”, explains Ignacio J. Molina.
As África González shows, the immune system has already seen a ‘picture of the enemy’ due to the vaccine and the infection, and even if it changes, it will continue to recognize it. “Coronavirus variants do not change so drastically to lose all immunity and omicron has mutations shared with other variants (beta, delta…) for which vaccines were still effective.”
If the worst-case scenario is true, what should be done?
“The worst prognosis would be that this new variant would be more transmissible, more virulent than the delta variant and vaccine resistant. If this happens, the current serum must be updated. Theoretically, it is an easy procedure, but it is necessary to add the entire production process, which would take two or three months”, says José Jiménez.
However, let’s not forget that the omicron variant has 32 mutations in the spike protein. “For this reason, it is possible that it will also be necessary to carry out some trial to assess the safety of the updated vaccine before its commercialization on a large scale”, he comments.
The worst prognosis would be that this new variant was more transmissible, virulent than the delta variant, and resistant to vaccines. If that happens, the current sera would have to be updated and this would take two or three months.
José Jiménez (King’s College)
Ignacio J. Molina also speaks of a period of around three months: “In fact, the contract for the extension of the order for vaccines signed between the European Union and pharmaceutical companies specifies that, if necessary, new versions of vaccines must be ready before 100 days”.
But for now, the best we can do is vaccinate all those over 18 who have not yet done so, send vaccines to developing countries and help with logistics so they can vaccinate the most vulnerable, with the aim of preventing the development of new variants, as Africa González comments.
This is how the researcher at the University of Vigo is blunt: “This global vaccination this can be done in a few weeks, as vaccines become available. However, this is not the case. It is a shame that vaccines are expiring and being thrown away in rich countries, when they can save lives. It is the cheapest and most effective procedure we have”.
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