Covid-19 part-5

Drawbacks of 1st Generation Vaccine

Some disadvantages associated with this vaccine are that the virus are restored to its previous active or mutated form and can affect the host all over again with intensified impact. It also does not suit the hosts or most of the population and the vaccination is required at multiple time in order to reverse the effects of infection. Hence, proper vaccination and dosage are needed to be recommended.

Second- Generation Vaccine

The virus is first to be inactivated by being exposed to light of higher energy such as UV, gamma-rays etc. or by treating with solvents such as β-propiolactone in order to destroy the infectivity while keeping the antigen intact. It has been found to be one of the best processes to stimulate responses for years. The infectious diseases such as hepatitis A are successfully treated by the vaccine produced by this method. Using this method, many vaccines have been tried to cope with MERS as well as SARS viruses. The solvent β-propiolactone alongwith Al2(OH)3 had been formulated to cope with SARS which enhances the responses based on immunity. The formaldehyde alongwith Al2(OH)3 was employed to boost the stimulation of immunity while keeping antigen intact in mice.

This vaccine has derived proteins containing a lot of antigens and proteins involving the recombination of DNA. This has been used for treating many diseases such as meningitis etc. But when it comes to treating with corona virus, this vaccine has proteins in fragments with high binding property. In this way, it is quite useful to enhance the immunity. In order to make the exposure of protein larger to increase immunity, the proteins were treated to be upgraded.

Third-Generation Vaccine

Unlike other generation vaccines, this vaccine instead of producing enhanced immunity produces the constant stimulation of responses. It has nucleic acids involved in it. It should majorly be used against typhoid, dengue than vaccines using inactivated viruses as it is quite good for treatment with such mild infections. This vaccine go well with the newly emerged viruses as it deals with the sequence of gene of virus. The recombination of DNA was done alongwith the use of inactivated or killed viruses such that the synergic effect of combination of both the processes was observed. It was found to be quite useful in treating with corona virus.

Efficiency of Vaccine

The designing of vaccine for SARS and MERS had not been done on time as there were no animal models available or the availability was less. Since, the SARS-CoV-2 spreads rapidly and covers the masses, the human body had not been used to perform the experiment for the optimization of vaccine. One of the biggest challenges in selecting of animal model was to determine whether the animal has the immunity against the pathogen being applied on it for the purpose of stimulating the immunogenic responses. The presence of relevant and suitable receptors for the action of pathogen is also0 vital for the process of binding of RBC of virus with the enzyme present in the body.

The administration of vaccine was also done in different modes such as subcutaneous, intramuscular, intranasal etc. As in most of the cases the track used by the virus is respiratory and sometimes genital, the mucosal vaccine is of the prime importance as it stimulates the responses exactly at the site where infection occurs. Thus, the determination of best route for administration of vaccine is quite important when it comes to determining the efficiency of vaccine. The immune responses are supposed to be enhanced by the use of suitable adjuvant. The interaction between adjuvant and antigen, functioning of adjuvant, dose of adjuvant are some difficult tasks to be done before selecting adjuvant while thew SARS-CoV-2 is spreading too fast.