Which immune response could cause a vaccine against COVID-19?

September 14, 2020

Immune reactions caused by vaccination can help protect the organism, or sometimes may aggravate the condition. It is especially important now when multiple vaccines against COVID-19 are being developed. The top immunologists analyse types of immune response to predict what kind of vaccine would be the best.

The COVID-19 pandemic is still ongoing, and it is a major challenge for healthcare professionals worldwide. Currently, there are several strategies of preventing the spread of the disease caused by the SARS-CoV-2 virus, including confinement or quarantine measures, social distancing, use of face masks, and good hygiene -- with frequent hand washing and application of antiseptics. However, it is clear that such restrictions affect our personal and professional lives. This is why vaccines against SARS-CoV-2 are being developed across the globe, as vaccination could help stop the pandemic. But these vaccines can be designed in a number of ways, and immune responses may be different. The recent keynote paper by Sechenov University scientists and their Swiss colleagues analyses which type of immune reaction would be more favourable so the vaccine could be effective. The study has been published in International Archives of Allergy and Immunology.

The vaccine, as expected, should efficiently induce high-affinity neutralising antibodies which would target SARS-CoV-2. At the same time, there are concerns that infection after vaccination might lead to eosinophilic lung disease and eosinophil associated Th2 immunopotentiation. Eosinophils are white blood cells involved in conditions such as bronchial asthma, eosinophilic oesophagitis, and hypereosinophilic syndromes. Currently, despite the limited available data, there is no indication that eosinophils play a protective or pathogenic role in COVID-19 infection.

However, eosinophils might still get involved when a person is vaccinated. For example, the research on potential vaccines against SARS-CoV-1, a closely related virus which caused an epidemic in 2002-2004, showed that pulmonary eosinophilia was induced in ferrets, monkeys, and mice after viral challenge. This fact suggests that vaccines against SARS-CoV-2 could also cause a similar immunopathology. Another source of complications might be the induced antibodies that promote viral uptake via Fc receptors.

According to the authors of the study, the most advantageous strategy should focus on vaccines that would induce the production of high-affinity virus-neutralising antibodies. These antibodies should block the interaction of SARS-CoV-2 with its cellular receptor -- angiotensin-converting enzyme 2 (ACE2). Successful vaccines are expected to polarise the T-cell response towards type 1 immunity and prevent the stimulation of cytokines which induce T-helper 2 immunity.

'From our experience with the SARS-1 vaccine, we know that mice which received the whole spike protein (responsible for ACE2 binding) exhibited some eosinophilic complications due to the Th-2 polarisation of the immune response', says Alexander Karaulov, Head of the Department of Clinical Immunology and Allergology at Sechenov University and one of the authors of the paper. 'At the same time, if the injected vaccine contained not the whole spike protein, but rather its receptor-binding domain which is directly involved in interactions with ACE2, immune-mediated pathologies (hypereosinophilic syndrome) could be avoided because of the high immunogenicity and high antibody titre. I believe this to be an important aspect, which remains poorly investigated'.
-end-
The article is the result of a collaboration between Sechenov University and the University of Bern (Switzerland).

Sechenov University

Related Immune Response Articles from Brightsurf:

Boosting chickens' own immune response could curb disease
Broiler chicken producers the world over are all too familiar with coccidiosis, a parasite-borne intestinal disease that stalls growth and winnows flocks.

Cells sacrifice themselves to boost immune response to viruses
Whether flu or coronavirus, it can take several days for the body to ramp up an effective response to a viral infection.

Children's immune response more effective against COVID-19
Children and adults exhibit distinct immune system responses to infection by the virus that causes COVID-19, a finding that helps explain why COVID-19 outcomes tend to be much worse in adults, researchers from Yale and Albert Einstein College of Medicine report Sept.

Which immune response could cause a vaccine against COVID-19?
Immune reactions caused by vaccination can help protect the organism, or sometimes may aggravate the condition.

Obesity may alter immune system response to COVID-19
Obesity may cause a hyperactive immune system response to COVID-19 infection that makes it difficult to fight off the virus, according to a new manuscript published in the Endocrine Society's journal, Endocrinology.

Immune response to Sars-Cov-2 following organ transplantation
Even patients with suppressed immune systems can achieve a strong immune response to Sars-Cov-2.

'Relaxed' T cells critical to immune response
Rice University researchers model the role of relaxation time as T cells bind to invaders or imposters, and how their ability to differentiate between the two triggers the body's immune system.

A novel mechanism that triggers a cellular immune response
Researchers at Baylor College of Medicine present comprehensive evidence that supports a novel trigger for a cell-mediated response and propose a mechanism for its action.

Platelets exacerbate immune response
Platelets not only play a key role in blood clotting, but can also significantly intensify inflammatory processes.

How to boost immune response to vaccines in older people
Identifying interventions that improve vaccine efficacy in older persons is vital to deliver healthy ageing for an ageing population.

Read More: Immune Response News and Immune Response Current Events
Brightsurf.com is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to Amazon.com.