Can Herd Immunity End the COVID-19 Pandemic?

 COVID-19 Pandemic

The COVID-19 pandemic has created an unprecedented situation around the world, causing millions of deaths and significant damage to the global economy. For more than a year, people have listened and waited for a herd immunity that can be achieved in the long term with near-universal vaccination. Does low infection rates around the world suggest that herd immunity to COVID-19 is just around the corner?

It has been more than a year since the world first encountered the highly contagious SARS-CoV-2 virus. The resistant coronavirus has managed to proliferate and spread through communities despite social distancing measures and other precautions to stop transmission. Now that several COVID-19 vaccines have been licensed and released for use, people are confident about the development of "herd immunity." According to the United States Centers for Disease Control and Prevention, herd immunity refers to the sufficient proportion of the population that becomes immune to a particular disease due to the development of antibodies, either by vaccination or by having previously contracted the disease.

If the majority of the population become immune after vaccination, they would not be able to spread the infection to vulnerable populations. Therefore, herd immunity ensures the protection of the remaining population and reduces the risks of transmission. The development of herd immunity seems like a practical solution for fighting COVID-19 infection and therefore vaccine inoculation campaigns are in full swing. There is no "magic threshold" but generally 50-90% of the population needs immunity before infection rates begin to decline; however, the number can vary depending on how contagious the virus is. For COVID-19, herd immunity is estimated to be between 70-90%, as immunity lasts longer.

How can we achieve herd immunity with SARS-CoV-2?

While wearing masks in public, social distancing and reducing the level of interaction can help lower infection rates, the virus could mutate as communities open up widely and become even more contagious. However, there are two ways to achieve herd immunity, whether the large proportion of the population is vaccinated or infected with the virus. Achieving herd immunity in the United States would require more than 230 million Americans to become infected. However, this could lead to more hospitalizations, ICU admissions and cost millions of lives. Patients with a mild infection may also have a severe illness for weeks or other long-term side effects. Therefore, achieving herd immunity through infection becomes a painfully misconceived thought.

Another way to achieve a threshold of herd immunity is through high vaccination rates, immunizing the population en masse so that society can return to normal. Inoculating the COVID-19 virus vaccine to 70-80% of the population will not only protect vulnerable populations at high risk but will also extend the benefits of immunization beyond the direct target population. Some of the vulnerable groups that depend on herd immunity for protection against disease include:

• People with compromised immune function
• People undergoing chemotherapy treatments
• People with HIV
• Freshly burned and babies
• Elderly people

Why is vaccine equity essential for building herd immunity?

While more than 1.65 billion doses of vaccines have been administered in rich nations, only 0.8% of all vaccines have been allocated to poor countries. Rich nations have become more focused on securing vaccines for their populations while ignoring investments in cooperative initiatives for the fair distribution of vaccines around the world. However, global vaccine coverage is imperative to manage the transmission of COVID-19. The imbalance is creating the need to move beyond outdated charitable models and instead focus on expanding manufacturing and distribution capacity around the world to increase immunization. The international community must empower nations by transferring technology or passing intellectual property exemptions in the World Trade Organization for vaccines so that poor countries can produce their own vaccines.

Vaccine nationalism may not be the best solution to defeat the spread of the virus. As rich countries are implementing national vaccination plans, new and emerging variants are reducing the effectiveness of vaccines against the virus. Even with vaccination shields, rich countries are vulnerable and their economies are also at risk. The International Chamber of Commerce predicts that if poor countries are not immunized, the global economy could lose $ 9.2 trillion, while funding for access to COVID-19 (ACT) tools would require only $ 22.9 billion. of dollars. In addition, the global allocation could postpone the launch of the national vaccine, but doing so will contribute to global herd immunity.

Obstacles to achieving herd immunity

• Vaccination vaccination

Some people are reluctant to get vaccinated due to a lack of information about the safety of vaccines or widespread misinformation about them. Also, religion, political party affiliation, or ethical obligations add to doubts about vaccines. According to one study, one in four young adults does not want to be vaccinated, endangering the health of unvaccinated older adults and facilitating the rise in vaccine variants. However, education and public health messages can encourage youth and young adults to reduce vaccinations.

• Appearance of new variants

As long as there are unvaccinated populations around the world, the COVID-19 virus will continue to mutate and become more dangerous. Even if wealthy nations were to successfully achieve herd immunity, the risk of transmission would not be reduced and booster injections might be necessary to ensure protection against variants that could evade the immune response elicited by current vaccines. Furthermore, the emergence of new strains worldwide due to the mutation in the coronavirus spike protein may not induce an antibody response in the infected person.

• Delayed arrival of vaccines for children

Children have been less susceptible to the coronavirus, but not all have escaped unscathed. In addition, infected young people have inadvertently transmitted the disease to other people and thus overall infection rates have increased. Although many vaccines are being tested to determine their effectiveness against the coronavirus in children, it is only a matter of time before the virus mutates and begins to attack the young population. The devastating wave of coronavirus in Brazil is targeting younger age groups and pregnant women. Despite growing paranoia, many young mothers are unwilling to seek vaccination for their children due to misinformation about vaccines and their possible side effects.

• Limited evidence on immunity after COVID infection

Some studies suggest that SARS-CoV-2 infection offers protection against the virus for at least one year. As antibodies enhance the immune response and confer strong resistance against variants of the coronavirus, becoming infected guarantees a certain level of protection. The level of immunity that vaccines provide varies depending on how the body responds. A single dose provides some level of protection, but a second dose is essential to achieve complete immunity. While scientists have evaluated the effectiveness of vaccines for most people in the first few months, they have no data on long-term immunity, as many vaccines have not even completed a year of follow-up.

Conclusion

Vaccinating as many people as possible can be important in slowing the spread of COVID-19. However, achieving herd immunity would not guarantee complete eradication of the coronavirus, as it is highly infectious and continues to evolve. Herd immunities vary at the global, national and community levels, and change over time; therefore, even when the threshold is reached, there would be small outbreaks due to uneven vaccine coverage.

According to TechSci Research Report on "Global Coronavirus Vaccine Market By Infection Type (SARS-CoV-2, SARS-CoV, MERS-CoV), By Vaccine Type (Viral Vaccine, Viral Vector Vaccine, nucleic acid vaccine, protein-based vaccine, and others), by product type (monovalent vaccine versus multivariate vaccine), by route of administration (intramuscular, oral, intranasal), by patient type (adult versus pediatric), per user (Hospitals, Clinics, Research Institutes), Others), By Region, Competition Forecast and Opportunities, 2026 ", the global coronavirus vaccine market is projected to grow at a formidable CAGR during the forecast period due to factors such as the increasing incidence of coronavirus infection, as well as the introduction of new vaccines on the market.

According to another TechSci research report on "Global Coronavirus Diagnostics Market By Test Type (Molecular Serology Versus Serology), By User (Multiple Versus Simple), By Test Full Time (1 Hour - 12 Hours, Less Than 60 minutes, 13 hours - 24 hours, more than 1 day), by end-user (hospitals, public health laboratories, private or commercial laboratories, medical laboratories, others), by region, competition forecast and opportunities, 2026 ", The global coronavirus diagnostic market is projected to reach a market value of USD15.57 billion by 2026. The growth can be attributed to the increasing incidence of coronavirus cases and the increasing use of diagnostic test kits for them.