Question

We all know that COVID-19 is wrecking havoc in the world today but recent debates on how to handle the COVID-19 outbreak, to what extent do the debates related to COVID-19 vaccines contain issues related to individual choice versus public health and distrust of the state?  

Answer 1

A novel, infectious pathogen like SARS-CoV-2 pathogen poses a greater risk to the population because it spread at a very high rate. Such pathogens undergo geometric growth. The lag phase or the initial growth of the pathogen in the population is slow but it increases rapidly at an exponential growth thereafter in the log or exponential phase.

Whenever such an epidemic or pandemic occurs the R0 value (average reproductive number) of the pathogen is calculated. The R0 value helps in calculating the risk that pathogen has on the population. Through any series of transmission, the pathogen might modify adequately that it accomplishes such efficiency of human-to-human transmission that and an epidemic becomes probable.

COVID-19 or coronavirus disease is caused by a novel coronavirus that was not previously known. Symptoms of this disease are:-

• · Fever and cough
• · Respiratory problems
• · Pneumonia

It spreads by direct or indirect contact with an infected person or through droplets from the sneeze.

This pandemic caused a high burden of mortality and morbidity across the globe. It will result in significant social, economic, and political disruption.

This global health crisis is unpending people's lives, spreading human suffering, and killing people.

Generally, any introduction of pathogen results in two outcomes- extinction or emergence. Extinction occurs if the novel pathogen dies out because of the failure in the adaption to human transmission or by stochastic extinction. Thus, the initiation only leads to a restricted fraction of infected hosts, which is suggested as the ‘outbreak size’.

A novel pathogen of zoonotic origin arises if it is adequately adapted for human transmission and starts to expand in a self-sustaining manner. In an extensive host population, the combined number of infectious hosts is unlimited as the period goes to infinity.

The interactions between the individuals can lead to a few who are infected propagating the pathogen into the wider population. For example- a person infected with this pathogen can transmit a disease to the other person who will be a carrier for 10 more people, and those people will communicate to another hundred and then a thousand people spreading the disease.

The vaccines help to limit the penetration of the disease into the population. The vaccines are used in the process of immunization. The immune system responds to these substances carrying an antigen. The vaccines are the weakened pathogens or their products that have been treated so that they are not able to cause the disease any longer. Active immunity is a type of immunity in which antibodies are produced by the immune system in response to the foreign antigen. Active immunity lasts for a longer period of time

When some new pathogen is developed and results in a pandemic, it is difficult to treat the patient with the disease because neither any vaccine is made for the pathogen nor there is any treatment of the disease. It takes time to study the structure, origin, and functioning of the pathogens because viruses mutate and adapt at a faster rate. For example- No vaccine is still made for the novel coronavirus but many patients have recovered from the disease. It is believed that a malarial drug, hydroxychloroquine is helping in the treatment of this disease.

It is possible to study the immune response after giving the vaccine by determining the amount of antibody present in the plasma sample. This process is called antibody titer. A primary response is generated after the first exposure to the vaccine. For a few days, antibodies are not present, then there is a rise in the titer and it levels off and slowly declines when the antibodies bind with the antigen or simply break down.

A secondary response is generated after the second exposure to the vaccine. The titer extremely increases in its level and then slowly declines. The immune response is extremely high at the time of the second exposure, thus, the second exposure is also called a booster. The disease symptoms are prevented even after the exposure of the individual to the disease-causing agent because the antibodies and the antigen-specific T cells are extremely high for a longer period of time in active immunity after the second exposure.

All segments of the population are affected by the COVID-19 outbreak and are mainly detrimental to members of those groups of the society that are in most vulnerable situations, including older persons, youth, persons with disabilities, indigenous people, and people living in poverty situations.

The effects of spatial host heterogeneity that divide the human population into interconnected communities effectively are noticeable. Different types of human movement between different communities such as cities and villages, including long-term labor migration and short-term commuting can be a major threat to the social distancing and can help the pathogen to spread even more.

The major consequences of the social crisis developed by the COVID-19 pandemic will be increased discrimination, exclusion, global unemployment, and inequality.