What are the benefits of COVID-19 vaccine?

When it comes to the benefits of vaccines, the first thing we are going to talk about is the stem of the vaccines - influenza virus. The origin of the vaccine can be traced back to the Spanish flu in 1918. After the outbreak of it, people had been trying hard to find the pathogen. Later, it was found that the swine flu virus was the cause of the flu. Finally, people started to develop vaccines because of this virus. Since then, the influenza has been treated before infection instead of post infection. It means that the vaccine is used for preventing virus, reducing the infection rate. 

The development of the vaccine is started from the pandemic of influenza virus. 

Influenza, as a virus, is a self-limiting disease after infecting human body. The widespread SARS-CoV-2 can also be categorized in this type. Generally speaking, drugs aiming at such viruses are often ineffective because the recovery of self-limiting diseases mainly depends on the body's own immunity, and most people could be healed by themselves. However, with the continuous heterozygosity and evolution of influenza virus, it may cause different diseases and mortality every year. In the lack of effective preventive measures, even the viruses with weak virulence may also cause mass mortality. Public health emergency caused by these pandemics often lead to the depletion or even collapse of medical resources, medical health supplies, and drug resources in a short term, and may eventually cause wider spread of virus and other serious consequences. 

Therefore, in order to cure influenza, a large scale of vaccine manufacture is needed for virus prevention and treatment before infection. It is a problem how to cultivate such swine flu virus, because the large-scale production of the influenza virus is the precondition of vaccine development. Later, researchers used chicken embryos to isolate and cultivate influenza viruses, and produced a set of standard plan for mass production of influenza vaccines, bringing the world's first influenza vaccine. Since then, the most important way to treat influenza is to vaccinate in advance, instead of post-influenza treatment and control. Vaccines can remarkably reduce the influenza infection rate of vaccinators and reduce the risk of subsequent serious complications.

However, with the mass production of influenza vaccines, influenza viruses have also evolved. Therefore, we can see that the type of vaccine will be continuously updated with the variation and evolution of influenza virus. Therefore, a global influenza surveillance network has been established to collect the development of influenza and predict its prevalence trend, so as to make prompt preparation for the production of vaccines suitable for the latest influenza. At present, for the latest influenza, influenza vaccine is still the most effective means to prevent the large-scale outbreak of influenza. 

Vaccines are still the most effective means to fight against with such widespread SARS-CoV-2 like the "large" flu. 

People often say that they don't know when and how the flu will come next time. However, is this new type of SARS-CoV-2 a brand new "large" flu? Is SARS-CoV-2 in 2020 a brand-new flu? Therefore, vaccines are still the most effective means for the prevention and treatment of such brand-new influenza. 

The herd barrier is of great significance, because the popularity of vaccines is closely related to herd resistance. 

But what we want to mention here is why infection cases of influenza viruses still frequently occur in cities after vaccines are produced. It is because influenza virus is constantly mutated and combined every year. It cannot be completely prevented since the novel mutated viruses cannot be prevented by former vaccines. Therefore, vaccines should be evolved and improved with the variation of viruses, until the new viruses are constantly eliminated. Therefore, in order to prevent influenza, vaccination is far more enough. The following methods shall also be taken, such as wearing a mask during the high season, avoiding gathering, washing hands frequently, and taking personal sanitary protection. SARS-CoV-2 is a new infectious disease caused by a new pathogen. At the beginning of the outbreak of COVID-19, people were not immune to it. Therefore, vaccination can establish a defense in the human body and prevent its rapid spread among others. What's the significance of the transfer of antibodies of SARS-CoV-2? 

In recent reports, the newborns carrying antibodies against SARS-CoV-2 can be found in China, Spain and other countries, which means that there are newborns with antibodies at birth in the world. It indicates that the ability of pregnant women to resist the virus can be inherited to the offspring to a certain extent. In the consideration of the risks, we do not recommend vaccination for pregnant women at present. Existing cases show that most pregnant women were infected with SARS-CoV-2 during pregnancy and recovered on their own, and then transferred the antiviral feature to their babies. American Journal of Obstetrics and Gynecology once published an article about the impact of SARS-CoV-2 on pregnant women. The most surprising thing about this research is that 78% of newborns of infection patients of COVID-19 are immune to the virus. This phenomenon shows that the capability of immunity to SARS-CoV-2 can be transferred to the offspring, which is the role of the self-protection mechanism of human and the good news during the pandemic. 

Summary 

In brief, judging from the global pandemic of COVID-19, the time or place of the next outbreak of newly discovered infectious diseases can never be determined, as well as the specific types of infectious virus-carrying pathogens. Therefore, human preparedness and the research and development process of vaccines cannot be overemphasized in the prevention of infectious diseases. However, it will be a long-term and tough task to eliminate SARS-CoV-2 by the vaccine because of its global spread.