COVID-19: What is Herd Immunity, and how does it work?
Herd immunity, also known as population immunity, is achieved when the effects of individual immunity are scaled to the population level. This population-level effect is frequently considered in the context of vaccination programs, which attempt to create herd immunity to protect individuals who cannot be vaccinated. Additionally, herd immunity refers to the indirect protection from a specific contagious disease when many individuals are immune. The World Health Organization supports achieving herd immunity. For some studies, herd immunity can attain through vaccination and natural infection.
Vaccination is the most prevalent way to combat and protect themselves from the virus. On the other hand, natural infection is achieved when most of the population contracts the disease and recovers. Antibodies are stimulated in the person's body because of existing or previous infections. Despite this, gaining herd immunity is too risky and can result in reinfection. With the advantages of vaccination and herd immunity, measles and mumps were prevalent but are now uncommon in most countries. As the world faces the coronavirus pandemic, health experts aim for herd immunity.
The COVID-19 pandemic has tremendously affected different countries' health and economic sectors. From December 2019 to February 2022, approximately 370 million COVID-19 cases have been reported worldwide. Therefore, this alarming situation has pushed the government and sectors to impose travel tests and vaccinations for the people.
What are vaccines?
Vaccines stimulate a person's immune system to produce disease-fighting proteins called 'antibodies,' Vaccinated individuals are protected from contracting the disease and transmitting the pathogen, effectively breaking any transmission chains. Being vaccinated, however, does not imply that people can disregard caution and endanger themselves and others.
In Europe, 81.4% of the adult population is fully vaccinated. The European Commission has secured more than 4.2 billion doses of vaccines and is continuously working to increase vaccine allocation. While the commission makes serious efforts to attain herd immunity, ensuring vaccines' safety and efficacy is also their concern. If you are a traveller and want to enter Europe, it would be better to identify the authorized vaccines in the EU and obtain a fit to fly certificate. As of January 2022, here are the authorized COVID-19 vaccines update from the European Medicines Agency (EMA).
1. BioNTech and Pfizer
The Pfizer BioNTech COVID-19 vaccine is 95% effective against symptomatic SARS-CoV-2 infection. Moreover, the vaccine is safe and effective for people with various conditions associated with an increased risk of severe disease.
This vaccine is a modified version of another virus (of the adenovirus family) that contains the gene for producing a protein present in SARS-CoV-2. A clinical trial comprising participants in the United States, South Africa, and Latin America discovered a 67% reduction in symptomatic COVID-19 cases among people who received Janssen. As a result, Janssen had a 67 per cent efficacy against moderate and severe SARS-CoV-2 infection with a single dose.
Novavax's coronavirus vaccine was engineered using nanoparticle technology through the coronavirus's genomic sequence. The vaccination induces the immune system to create antibodies when it is injected. In clinical trials, it has been found that Novavax has an 89.7% success rate against coronavirus and a 100% success rate against mild and severe illness.
The EMA conducted a rigorous assessment of the Moderna COVID-19 vaccine's quality, safety, and efficacy before authorizing its use across the European Union. The Moderna vaccine was shown to be 94.1 per cent effective against COVID-19, 14 days after the initial dose.
The AstraZeneca vaccine is safe and effective at protecting individuals against the severe complications associated with COVID-19, including death, hospitalization, and severe illness. In addition, the vaccine is 76% effective against symptomatic SARS-CoV-2 infection. However, this is only applicable to occurrences happening 15 days after the second dose
How does herd immunity work?
The main goal of herd immunity is to help people contract the disease and ensure that they are protected against coronavirus. Experts think that for herd immunity to be successful, 70% to 90% of a population must be immune to disease through infection, recovery, or vaccination.
When enough people get vaccinated, everyone, including those too young or sick to receive vaccinations, gains indirect protection against disease transmission. Because there are fewer available to infect others, an infectious disease is less likely to spread from person to person. Even if a person does become ill, the likelihood of an outbreak is low due to the increased immunity.
To sustain herd immunity, vaccines must be efficient. This effectiveness does not have to be perfect to increase herd immunity. If they have 70% vaccine efficacy, it is enough for a population to develop herd immunity.
While countries are continuously conducting vaccination programs to achieve herd immunity, it is essential to promote COVID-19 testing, either through antigen tests or PCR tests. If you are hesitant to get vaccinated, you must get tested whenever you plan to travel or feel the symptoms of coronavirus. Getting tested can help contract the spread of coronavirus and reduce the risk of breakthrough infections.
Countries must consider supplementing existing short-term immunization policies to protect the health system and at-risk populations. This should include developing a longer-term strategy for achieving and maintaining high levels of population immunity and prevention such as:
· use of masks
· social distancing
· effective testing and tracing
· strengthening health system resilience
As societies seek to recover, combining realistic expectations of herd immunity would enable policymakers to make educated choices about which vital sectors and services of the economy to prioritize for immediate reopening. In addition, these circumstances will not continue indefinitely. The pandemic will eventually pass, and medicine will win. However, until then, the only way to combat the sickness, restore businesses and re-establish a strong economy is for everyone to stay vigilant from the virus.
Find your reliable testing provider
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