Developing Universal Vaccines for Present and Future Corona-viruses

North-Western University (USA) developing Universal vaccines

New drugs are being developed to fight the current (SARS-CoV-2) and possible future corona-viruses or their variants. In focus is the key non-structural protein (nsp16) present in all coronaviruses, and an identifier that helps the virus hide from the immune system. A part of the protein binds the fragment held in place by a metal ion. Efforts are being made to make drugs that block only this component but do not affect  similar other proteins from human cells. This drug is able to combat viruses responsible for other respiratory diseases also. The NWU scientists have  succeeded in purification and crystallization of this protein  and have  studied more than 70 different viruses and reveal their interactions with possible drugs and antibodies. This work is available to the global community for designing new drugs for treating the current and future pandemics.

Materials to remove Infected Aerosols and Droplets

Plexiglass barriers are used at present for blocking virus transmission by targeting the virus-laden aerosols and infectious respiratory droplets. The plexiglass dividers deflect these harmful aerosols and droplets, causing them to move away but they remain in the air. Researchers have developed a new transparent and viscous liquid (polyelectrolyte polymer), that captures these floating aerosols and droplets, and removes them from air. This material  can be painted on plastic, glass, wood, metal, concrete, and textile surfaces. Floating particles colliding with coated surfaces get absorbed and dry up, reducing air-borne infectious diseases. Surface-trapped pathogens can then be inactivated by pre-applied sanitization.  

Understanding Viral Mutations

Coronavirus, with spike proteins on its surface, binds to ACE2, a protein receptor found on the surface of cells in our body, which get cleaved, allowing genetic material from the virus to enter the host cell. The virus manipulates the host cell to allow it (the coronavirus) to replicate and spread. Errors in its makeup cause it to undergo genetic changes or mutations. Some mutations make the virus more transmissible or more infectious, some help it to evade the immune response, making vaccines less effective.

How coronavirus wreaks Havoc

Detailed atomic-level studies show how the SARS-CoV-2 “envelope” protein gets bound to an essential human protein. Scientists obtained details of the interaction by mixing the two proteins together, freezing the sample rapidly, and then studying them with a powerful Electron Microscope. This uses high-energy electrons to interact with the sample, just as light microscopes use beams of light. Electron waves allowed them to see at much smaller scales due to their extremely short wavelength (nearly a million  times shorter than visible light). 

The “envelope” assembles new viruses inside infected cells by binding to human cell-junction proteins. The new discovery is focused on drugs that block this interaction. When lung cell junctions are disrupted, immune cells rush to control the damage, releasing small proteins called cytokines. However, the virus pulls out the cytokines from cell junction, which helps the virus to spread. With weakened cell-cell connections, it is easier for the viruses to travel through the bloodstream to infect other organs. 

Universal Vaccine for flu / Coronavirus

Hem-agglutinin (HA) is a protein on the surface of the virus that attaches to receptors on host cells. A new study shows that antibodies targeting stable portions of HA, were effective at fighting the virus. In earlier H1N1 pandemics, people developed strong and effective immune responses, suggesting a strategy for developing universal flu vaccines that generate the same responses,  and we do not require a new vaccine every year. Scientists are trying to anticipate the variants of the virus, but sometimes new, unexpected variants emerge, so that the vaccine may not be very effective. To avoid this, researchers are trying to develop a powerful universal vaccine  for any virus strain.  

Encounter with virus a second or third time, gets a response completely dominated by antibodies against more variable parts of the virus though it is not always helpful with other, different versions. Already, two doses had become necessary and now a third booster dose is under consideration as antibodies wane over time. Studies suggest that antibody levels jump five- to 10-fold after a third dose, compared to their second dose months earlier.

Scientists are trying to design a vaccine that recreates that initial encounter with H1N1, using a version of the HA protein that retains the powerful antibody-inducing components, and replaces the variable, without disturbing the immune system. In the past, two of the four pandemics were caused by H1N1 influenza, including the Spanish Flu that killed about 100 million people. The new findings are reassuring in the fight against any future H1 virus pandemic. We now have the immune toolkit ready to protect ourselves. But we have to get the right vaccine to do that.

Cambridge University studies Mutations in Alpha variant

During 2020, Cambridge scientists observed SARS-CoV-2 mutating in the case of an immune-compromised patient treated with convalescent plasma. They saw the emergence of a key mutation (the deletion of two amino acids, H69/V70), in spike protein. This deletion was found in B1.1.7, the ‘Alpha variant‘. Their deletion, present in more than 600,000 genome sequences worldwide, did not allow the virus to ‘escape’, after vaccination. A mutation that enables the virus to evade the immune system affects its ability to replicate.  Understanding mutations is important because that enables us to predict how a new variant might behave when it is first identified and we can implement public health and containment strategies early on.

 The Other Aspects

Vaccines require facilities for safe transportation and storage at ultra-cold temperatures,  as low as – 700 C.  There is a great need to stock  essentials like sanitizers, medical oxygen, personal protection equipment (PPE), ventilators, deep freezers for vaccines and other accessories in well-equipped hospitals in every city and big town (in every country) for emergent situations. International co-operation is essential as many countries can not control these pandemics in isolation. Institutional and social safeguards are needed for co-ordination. In the past, disadvantaged neighborhoods experienced more infections and deaths. Factors that fueled inequities include population density, access to healthy food and health care, capacity to socially isolate and the timely availability of vaccines. Human survival is linked with climate changes, as well as the co-odinated protection of people of all countries from future respiratory pandemics.

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