Starting with an overall view of the subject, this article delves into the concept of vaccines, their types, Corbevax in particular, and its spike protein. It further discusses the mechanism of vaccines in treating viral infection, with an additional emphasis on Corbevax. This is followed by an exploration of various types of vaccines currently available. The focus then shifts to recent news about India’s government allowing Covishield or Covaxin recipients to take Corbevax as a third booster shot.
India’s New Vaccine Regulation: Corbevax as Third Booster Shot
The government of India recently made an announcement that those who have received their first or second dose of Covishield or Covaxin for Covid-19 can opt for Corbevax as their third booster shot. The previous regulation stipulated that the third dose had to be the same vaccine administered for the first and second doses. But, India’s drug regulator has now given approval for Corbevax to be used as a heterologous Covid booster dose for individuals aged 18 years and above.
Pending Approval: WHO’s Emergency Use Listing (EUL)
Despite its use in India, Corbevax is still awaiting the World Health Organisation’s Emergency Use Listing (EUL). EUL is a risk-based procedure for assessing and listing unlicensed vaccines, therapeutics, and in-vitro diagnostics. Its main aim is to expedite the availability of these products to people affected by a public health emergency. Many countries require people to get vaccinated with a product from the WHO’s approved list before they can travel internationally.
More About Corbevax: India’s Indigenously Developed Vaccine
Corbevax is a Receptor Binding Domain (RBD) protein sub-unit vaccine against Covid that has been developed indigenously in India. This form of vaccine can be stored at a temperature range between 2-8 degrees Celsius, which is well-suited to India’s conditions. Doses are typically administered 28 days apart.
The vaccine works by introducing a specific part of the SARS-CoV-2 virus, known as the spike protein, to the body. This protein is key for the virus to enter cells in the body, thus allowing it to replicate and cause disease. However, when this protein alone is administered to the body, it is not expected to be harmful as the rest of the virus is absent. The body is then likely to build an immune response against this spike protein. This helps prepare the immune system for any future infection by the actual virus, making it less likely for the person to fall severely ill.
An Overview of Other Vaccine Types
There are various types of vaccines available; each differs in how they interact with the body to build immunity. Inactivated vaccines use the killed version of the germ causing a disease. They are created by inactivating a pathogen, typically using heat or chemicals. Live-attenuated vaccines, on the other hand, use a weakened form of the germ that causes a disease.
Messenger (m) RNA vaccines work by making proteins to trigger an immune response. They carry several benefits compared to other vaccine types, such as shorter manufacturing times and no risk of causing disease in the person getting vaccinated. Toxoid vaccines create immunity to the parts of the germ that cause a disease instead of the whole germ itself.
Viral vector vaccines use a modified version of a different virus as a vector to deliver protection. Different viruses, including influenza, vesicular stomatitis virus (VSV), measles virus, and adenovirus, have been used as vectors.
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In relation to recent developments about ‘Recombinant Vector Vaccines’, genetic engineering is applied in the development of these vaccines, where bacteria and viruses are used as vectors. Recombinant vector vaccines stimulate the immune system as in natural infections and have intrinsic adjuvant properties. They are used as a channel for entry into the host organism.
Technological advancements are being readily employed to manage the COVID-19 pandemic. The development of vaccines, including Corbevax, is a key result of this technological progress. The use of technology is likely to continue playing a significant role in managing this and future pandemics.
